Exoplanet - Blog Posts

Meet Our Superhero Space Telescopes!

While the first exoplanets—planets beyond our solar system—were discovered using ground-based telescopes, the view was blurry at best. Clouds, moisture, and jittering air molecules all got in the way, limiting what we could learn about these distant worlds.

A superhero team of space telescopes has been working tirelessly to discover exoplanets and unveil their secrets. Now, a new superhero has joined the team—the James Webb Space Telescope. What will it find? Credit: NASA/JPL-Caltech

To capture finer details—detecting atmospheres on small, rocky planets like Earth, for instance, to seek potential signs of habitability—astronomers knew they needed what we might call “superhero” space telescopes, each with its own special power to explore our universe. Over the past few decades, a team of now-legendary space telescopes answered the call: Hubble, Chandra, Spitzer, Kepler, and TESS.

Much like scientists, space telescopes don't work alone. Hubble observes in visible light—with some special features (superpowers?)—Chandra has X-ray vision, and TESS discovers planets by looking for tiny dips in the brightness of stars.

Kepler and Spitzer are now retired, but we're still making discoveries in the space telescopes' data. Legends! All were used to tell us more about exoplanets. Spitzer saw beyond visible light into the infrared and was able to make exoplanet weather maps! Kepler discovered more than 3,000 exoplanets.

Three space telescopes studied one fascinating planet and told us different things. Hubble found that the atmosphere of HD 189733 b is a deep blue. Spitzer estimated its temperature at 1,700 degrees Fahrenheit (935 degrees Celsius). Chandra, measuring the planet’s transit using X-rays from its star, showed that the gas giant’s atmosphere is distended by evaporation.

Adding the James Webb Space Telescope to the superhero team will make our science stronger. Its infrared views in increased ranges will make the previously unseen visible.

Soon, Webb will usher in a new era in understanding exoplanets. What will Webb discover when it studies HD 189733 b? We can’t wait to find out! Super, indeed.

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Travel to Exotic Destinations in our Galaxy!

The planets beyond our solar system – exoplanets – are so far away, often trillions of miles, that we don’t have the technology to truly see them. Even the best photos show the planets as little more than bright dots. We’ve confirmed more than 5,000 exoplanets, but we think there are billions. Space telescopes like Hubble aren’t able to take photos of these far-off worlds, but by studying them in different wavelengths of light (colors), we’ve learned enough about conditions on these planets that we can illustrate them.

We know, thanks to the now-retired Spitzer Space Telescope, that there is a thick atmosphere on a planet called 55 Cancri e about 40 light-years away. And Hubble found silicate vapor in the atmosphere of this rocky world. We also know it’s scorching-close to its Sun-like star, so … lava. Lots and lots of lava. This planet is just one of the many that the James Webb Space Telescope will soon study, telling us even more about the lava world!

You can take a guided tour of this planet (and others) and see 360-degree simulations at our new Exoplanet Travel Bureau.

Travel to the most exotic destinations in our galaxy, including:

Kepler-16b, a planet with two suns.

Then there’s PSO J318.5-22, a world with no sun that wanders the galaxy alone. The nightlife would never end on a planet without a star.

TRAPPIST-1e, which will also be studied by the Webb Space Telescope, is one of seven Earth-sized planets orbiting a star about 40 light-years from Earth. It’s close enough that, if you were standing on this exoplanet, you could see our Sun as a star in the Leo constellation! You can also see it on the poster below: look for a yellow star to the right of the top person’s eye.

We haven’t found life beyond Earth (yet) but we’re looking. Meanwhile, we can imagine the possibility of red grass and other plants on Kepler-186f, a planet orbiting a red dwarf star.

We can also imagine what it might be like to skydive on a super-Earth about seven times more massive than our home planet. You would fall about 35% faster on a super-Earth like HD 40307g, making for a thrilling ride!

Any traveler is going to want to pick up souvenirs, and we have you covered. You can find free downloads of all the posters here and others! What are you waiting for? Come explore with us!

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Image credits: NASA/JPL-Caltech

Spotted: signs of a planet about 28 million light-years away 🔎 🪐

For the first time, astronomers may have detected an exoplanet candidate outside of the Milky Way galaxy. Exoplanets are defined as planets outside of our Solar System. All other known exoplanets and exoplanet candidates have been found in the Milky Way, almost all of them less than about 3,000 light-years from Earth.

This new result is based on transits, events in which the passage of a planet in front of a star blocks some of the star's light and produces a characteristic dip. Researchers used our Chandra X-ray Observatory to search for dips in the brightness of X-rays received from X-ray bright binaries in the spiral galaxy Messier 51, also called the Whirlpool Galaxy (pictured here). These luminous systems typically contain a neutron star or black hole pulling in gas from a closely orbiting companion star. They estimate the exoplanet candidate would be roughly the size of Saturn, and orbit the neutron star or black hole at about twice the distance of Saturn from the Sun.

This composite image of the Whirlpool Galaxy was made with X-ray data from Chandra and optical light from our Hubble Space Telescope.

Credit: X-ray: NASA/CXC/SAO/R. DiStefano, et al.; Optical: NASA/ESA/STScI/Grendler

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Got a question about black holes? Let’s get to the bottom of these odd phenomena. Ask our black hole expert anything! 

Black holes are mystifying yet terrifying cosmic phenomena. Unfortunately, people have a lot of ideas about them that are more science fiction than science. Don’t worry! Our black hole expert, Jeremy Schnittman, will be answering your your questions in an Answer Time session on Wednesday, October 2 from 3pm - 4 pm ET here on NASA’s Tumblr! Make sure to ask your question now by visiting http://nasa.tumblr.com/ask!

Jeremy joined the Astrophysics Science Division at our Goddard Space Flight Center in 2010 following postdoctoral fellowships at the University of Maryland and Johns Hopkins University. His research interests include theoretical and computational modeling of black hole accretion flows, X-ray polarimetry, black hole binaries, gravitational wave sources, gravitational microlensing, dark matter annihilation, planetary dynamics, resonance dynamics and exoplanet atmospheres. He has been described as a "general-purpose astrophysics theorist," which he regards as quite a compliment. 

Fun Fact: The computer code Jeremy used to make the black hole animations we featured last week is called "Pandurata," after a species of black orchid from Sumatra. The name pays homage to the laser fusion lab at the University of Rochester where Jeremy worked as a high school student and wrote his first computer code, "Buttercup." All the simulation codes at the lab are named after flowers.

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TESS’s first-year of planet-hunting was out of this world

Have you ever looked up at the night sky and wondered ... what other kinds of planets are out there? Our Transiting Exoplanet Survey Satellite (TESS) just spent its first year bringing us a step closer to exploring the planets around the nearest and brightest stars in the southern sky and is now doing the same in the north.

TESS has been looking for dips in the brightness of stars that could be a sign of something we call “transits.” A transit happens when a planet passes between its star and us. It’s like when a bug flies in front of a light bulb. You may not notice the tiny drop in brightness when the bug blocks some of the light from reaching your eyes, but a sensitive camera could. The cameras on TESS are designed to detect those tiny drops in starlight caused by a transiting planet many light-years away.

In the last year TESS has found 24 planets and more than 900 new candidate planets. And TESS is only halfway through its goal of mapping over three-fourths of our skies, which means there’s plenty more to discover!

TESS has been looking for planets around the closest, brightest stars because they will be the best planets to explore more thoroughly with future missions. We can even see a few of these stars with our own eyes, which means we’ve been looking at these planets for millions of years and didn’t even know it.

We spent thousands of years staring at our closest neighbor, the Moon, and asking questions: What is it like? Could we live there? What is it made of (perhaps cheese?). Of course, now we can travel to the Moon and explore it ourselves (turns out, not made of cheese).

But for the worlds TESS is discovering, the commute to answer those questions would be killer. It took 35 years for Voyager 1 to cross into interstellar space (the region between stars), and it’s zipping along at over 38,000 mph! At that rate it would take more than a half-a-million years to reach the nearest stars and planets that TESS is discovering.

While exploring these distant worlds in person isn’t an option, we have other ways of learning what they are like. TESS can tell us where a planet is, its size and its overall temperature, but observatories on the ground and in space like our upcoming James Webb Space Telescope will be able to learn even more — like whether or not a planet has an atmosphere and what it’s made of.

Here are a few of the worlds that our planet hunter discovered in the last year.

Earth-Sized Planet

The first Earth-sized planet discovered by TESS is about 90% the size of our home planet and orbits a star 53 light-years away. The planet is called HD 21749 c (what a mouthful!) and is actually the second planet TESS has discovered orbiting that star, which you can see in the southern constellation Reticulum.

The planet may be Earth-sized, but it would not be a pleasant place to live. It’s very close to its star and could have a surface temperature of 800 degrees Fahrenheit, which would be like sitting inside a commercial pizza oven.

Water World?

The other planet discovered in that star system, HD 21749 b, is about three times Earth’s size and orbits the star every 36 days. It has the longest orbit of any planet within 100 light-years of our solar system detected with TESS so far.

The planet is denser than Neptune, but isn’t made of rock. Scientists think it might be a water planet or have a totally new type of atmosphere. But because the planet isn’t ideal for follow-up study, for now we can only theorize what the planet is actually like. Could it be made of pudding? Maybe … but probably not.

Magma World

One of the first planets TESS discovered, called LHS 3844 b, is roughly Earth’s size, but is so close to its star that it orbits in just 11 hours. For reference, Mercury, which is more than two and a half times closer to the Sun than we are, completes an orbit in just under three months.

Because the planet is so close to its star, the day side of the planet might get so hot that pools and oceans of magma form on its rocky surface, which would make for a rather unpleasant day at the beach.    

TESS’s Smallest Planet

The smallest planet TESS has discovered, called L 98-59 b, is between the size of Earth and Mars and orbits its star in a little over two days. Its star also hosts two other TESS-discovered worlds.

Because the planet lies so close to its star, it gets 22 times the radiation we get here on Earth. Yikes! It is also not located in its star’s habitable zone, which means there probably isn’t any liquid water on the surface. Those two factors make it an unlikely place to find life, but scientists believe it will be a good candidate for follow-up studies by other telescopes.

Other Data

While TESS’s team is hunting for planets around close, bright stars, it’s also collecting information on all sorts of other things. From transits around dimmer, farther stars to other objects in our solar system and events outside our galaxy, data from TESS can help astronomers learn a lot more about the universe. Comets and black holes and supernovae, oh my!

Interested in joining the hunt? TESS’s data are released online, so citizen scientists around the world can help us discover new worlds and better understand our universe.

Stay tuned for TESS’s next year of science as it monitors the stars that more than 6.5 billion of us in the northern hemisphere see every night.

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A Tour of Storms Across the Solar System

Earth is a dynamic and stormy planet with everything from brief, rumbling thunderstorms to enormous, raging hurricanes, which are some of the most powerful and destructive storms on our world. But other planets also have storm clouds, lightning — even rain, of sorts. Let’s take a tour of some of the unusual storms in our solar system and beyond.

Tune in May 22 at 3 p.m. for more solar system forecasting with NASA Chief Scientist Jim Green during the latest installment of NASA Science Live: https://www.nasa.gov/nasasciencelive.

1. At Mercury: A Chance of Morning Micrometeoroid Showers and Magnetic ‘Tornadoes’

Mercury, the planet nearest the Sun, is scorching hot, with daytime temperatures of more than 800 degrees Fahrenheit (about 450 degrees Celsius). It also has weak gravity — only about 38% of Earth's — making it hard for Mercury to hold on to an atmosphere.

Its barely there atmosphere means Mercury doesn’t have dramatic storms, but it does have a strange "weather" pattern of sorts: it’s blasted with micrometeoroids, or tiny dust particles, usually in the morning. It also has magnetic “tornadoes” — twisted bundles of magnetic fields that connect the planet’s magnetic field to space.

2. At Venus: Earth’s ‘Almost’ Twin is a Hot Mess

Venus is often called Earth's twin because the two planets are similar in size and structure. But Venus is the hottest planet in our solar system, roasting at more than 800 degrees Fahrenheit (430 degrees Celsius) under a suffocating blanket of sulfuric acid clouds and a crushing atmosphere. Add to that the fact that Venus has lightning, maybe even more than Earth. 

In visible light, Venus appears bright yellowish-white because of its clouds. Earlier this year, Japanese researchers found a giant streak-like structure in the clouds based on observations by the Akatsuki spacecraft orbiting Venus.

3. At Earth: Multiple Storm Hazards Likely

Earth has lots of storms, including thunderstorms, blizzards and tornadoes. Tornadoes can pack winds over 300 miles per hour (480 kilometers per hour) and can cause intense localized damage.

But no storms match hurricanes in size and scale of devastation. Hurricanes, also called typhoons or cyclones, can last for days and have strong winds extending outward for 675 miles (1,100 kilometers). They can annihilate coastal areas and cause damage far inland.

4. At Mars: Hazy with a Chance of Dust Storms

Mars is infamous for intense dust storms, including some that grow to encircle the planet. In 2018, a global dust storm blanketed NASA's record-setting Opportunity rover, ending the mission after 15 years on the surface.

Mars has a thin atmosphere of mostly carbon dioxide. To the human eye, the sky would appear hazy and reddish or butterscotch colored because of all the dust suspended in the air. 

5. At Jupiter: A Shrinking Icon

It’s one of the best-known storms in the solar system: Jupiter’s Great Red Spot. It’s raged for at least 300 years and was once big enough to swallow Earth with room to spare. But it’s been shrinking for a century and a half. Nobody knows for sure, but it's possible the Great Red Spot could eventually disappear.

6. At Saturn: A Storm Chasers Paradise

Saturn has one of the most extraordinary atmospheric features in the solar system: a hexagon-shaped cloud pattern at its north pole. The hexagon is a six-sided jet stream with 200-mile-per-hour winds (about 322 kilometers per hour). Each side is a bit wider than Earth and multiple Earths could fit inside. In the middle of the hexagon is what looks like a cosmic belly button, but it’s actually a huge vortex that looks like a hurricane.

Storm chasers would have a field day on Saturn. Part of the southern hemisphere was dubbed "Storm Alley" by scientists on NASA's Cassini mission because of the frequent storm activity the spacecraft observed there. 

7. At Titan: Methane Rain and Dust Storms

Earth isn’t the only world in our solar system with bodies of liquid on its surface. Saturn’s moon Titan has rivers, lakes and large seas. It’s the only other world with a cycle of liquids like Earth’s water cycle, with rain falling from clouds, flowing across the surface, filling lakes and seas and evaporating back into the sky. But on Titan, the rain, rivers and seas are made of methane instead of water.

Data from the Cassini spacecraft also revealed what appear to be giant dust storms in Titan’s equatorial regions, making Titan the third solar system body, in addition to Earth and Mars, where dust storms have been observed.

8. At Uranus: A Polar Storm

Scientists were trying to solve a puzzle about clouds on the ice giant planet: What were they made of? When Voyager 2 flew by in 1986, it spotted few clouds. (This was due in part to the thick haze that envelops the planet, as well as Voyager's cameras not being designed to peer through the haze in infrared light.) But in 2018, NASA’s Hubble Space Telescope snapped an image showing a vast, bright, stormy cloud cap across the north pole of Uranus.

9. At Neptune: Methane Clouds

Neptune is our solar system's windiest world. Winds whip clouds of frozen methane across the ice giant planet at speeds of more than 1,200 miles per hour (2,000 kilometers per hour) — about nine times faster than winds on Earth.

Neptune also has huge storm systems. In 1989, NASA’s Voyager 2 spotted two giant storms on Neptune as the spacecraft zipped by the planet. Scientists named the storms “The Great Dark Spot” and “Dark Spot 2.”

10. It’s Not Just Us: Extreme Weather in Another Solar System

Scientists using NASA’s Hubble Space Telescope made a global map of the glow from a turbulent planet outside our solar system. The observations show the exoplanet, called WASP-43b, is a world of extremes. It has winds that howl at the speed of sound, from a 3,000-degree-Fahrenheit (1,600-degree-Celsius) day side, to a pitch-black night side where temperatures plunge below 1,000 degrees Fahrenheit (500 degrees Celsius).

Discovered in 2011, WASP-43b is located 260 light-years away. The planet is too distant to be photographed, but astronomers detected it by observing dips in the light of its parent star as the planet passes in front of it.

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Five Facts About the Kepler Space Telescope That Will Blow You Away!

Ten years ago, on March 6, 2009, a rocket lifted off a launch pad at Cape Canaveral Air Force Station in Florida. It carried a passenger that would revolutionize our understanding of our place in the cosmos--NASA’s first planet hunter, the Kepler space telescope. The spacecraft spent more than nine years in orbit around the Sun, collecting an unprecedented dataset for science that revealed our galaxy is teeming with planets. It found planets that are in some ways similar to Earth, raising the prospects for life elsewhere in the cosmos, and stunned the world with many other first-of-a-kind discoveries. Here are five facts about the Kepler space telescope that will blow you away:

Kepler observed more than a half million stars looking for planets beyond our solar system.

It discovered more than 2,600 new worlds…

…many of which could be promising places for life.

Kepler’s survey revealed there are more planets than stars in our galaxy.

The spacecraft is now drifting around the Sun more than 94 million miles away from Earth in a safe orbit.

NASA retired the Kepler spacecraft in 2018. But to this day, researchers continue to mine its archive of data, uncovering new worlds.

*All images are artist illustrations. Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

The Kepler space telescope has shown us our galaxy is teeming with planets — and other surprises

The Kepler space telescope has taught us there are so many planets out there, they outnumber even the stars. Here is a sample of these wondrous, weird and unexpected worlds (and other spectacular objects in space) that Kepler has spotted with its “eye” opened to the heavens.

Kepler has found that double sunsets really do exist.

Yes, Star Wars fans, the double sunset on Tatooine could really exist. Kepler discovered the first known planet around a double-star system, though Kepler-16b is probably a gas giant without a solid surface.

Kepler has gotten us closer to finding planets like Earth.

Nope. Kepler hasn’t found Earth 2.0, and that wasn’t the job it set out to do. But in its survey of hundreds of thousands of stars, Kepler found planets near in size to Earth orbiting at a distance where liquid water could pool on the surface. One of them, Kepler-62f, is about 40 percent bigger than Earth and is likely rocky. Is there life on any of them? We still have a lot more to learn.

This sizzling world is so hot iron would melt!

One of Kepler’s early discoveries was the small, scorched world of Kepler-10b. With a year that lasts less than an Earth day and density high enough to imply it’s probably made of iron and rock, this “lava world” gave us the first solid evidence of a rocky planet outside our solar system. 

If it’s not an alien megastructure, what is this oddly fluctuating star?

When Kepler detected the oddly fluctuating light from “Tabby’s Star,” the internet lit up with speculation of an alien megastructure. Astronomers have concluded it’s probably an orbiting dust cloud.  

Kepler caught this dead star cannibalizing its planet.

What happens when a solar system dies? Kepler discovered a white dwarf, the compact corpse of a star in the process of vaporizing a planet.

These Kepler planets are more than twice the age of our Sun!

The five small planets in Kepler-444 were born 11 billion years ago when our galaxy was in its youth. Imagine what these ancient planets look like after all that time?

Kepler found a supernova exploding at breakneck speed.

This premier planet hunter has also been watching stars explode. Kepler recorded a sped-up version of a supernova called a “fast-evolving luminescent transit” that reached its peak brightness at breakneck speed. It was caused by a star spewing out a dense shell of gas that lit up when hit with the shockwave from the blast. 

* All images are artist illustrations.

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10 Steps to Confirm a Planet Around Another Star

So you think you found an exoplanet -- a planet around another star? It’s not as simple as pointing a telescope to the sky and looking for a planet that waves back. Scientists gather many observations and carefully analyze their data before they can be even somewhat sure that they’ve discovered new worlds.

Here are 10 things to know about finding and confirming exoplanets.

This is an illustration of the different elements in our exoplanet program, including ground-based observatories, like the W. M. Keck Observatory, and space-based observatories like Hubble, Spitzer, Kepler, TESS, James Webb Space Telescope, WFIRST and future missions.

1. Pick your tool to take a look.

The vast majority of planets around other stars have been found through the transit method so far. This technique involves monitoring the amount of light that a star gives off over time, and looking for dips in brightness that may indicate an orbiting planet passing in front of the star.

We have two specialized exoplanet-hunting telescopes scanning the sky for new planets right now -- Kepler and the Transiting Exoplanet Survey Satellite (TESS) -- and they both work this way. Other methods of finding exoplanets include radial velocity (looking for a “wobble” in a star's position caused by a planet’s gravity), direct imaging (blocking the light of the star to see the planet) and microlensing (watching for events where a star passes in front of another star, and the gravity of the first star acts as a lens).

Here’s more about finding exoplanets.

2. Get the data.

To find a planet, scientists need to get data from telescopes, whether those telescopes are in space or on the ground. But telescopes don’t capture photos of planets with nametags. Instead, telescopes designed for the transit method show us how brightly thousands of stars are shining over time. TESS, which launched in April and just began collecting science data, beams its stellar observations back to Earth through our Deep Space Network, and then scientists get to work.

3. Scan the data for planets.

Researchers combing through TESS data are looking for those transit events that could indicate planets around other stars. If the star’s light lessens by the same amount on a regular basis -- for example, every 10 days -- this may indicate a planet with an orbital period (or “year”) of 10 days. The standard requirement for planet candidates from TESS is at least two transits -- that is, two equal dips in brightness from the same star.

4. Make sure the planet signature couldn’t be something else.

Not all dips in a star's brightness are caused by transiting planets. There may be another object -- such as a companion star, a group of asteroids, a cloud of dust or a failed star called a brown dwarf, that makes a regular trip around the target star. There could also be something funky going on with the telescope’s behavior, how it delivered the data, or other “artifacts” in data that just aren’t planets. Scientists must rule out all non-planet options to the best of their ability before moving forward.

5. Follow up with a second detection method.

Finding the same planet candidate using two different techniques is a strong sign that the planet exists, and is the standard for “confirming” a planet. That’s why a vast network of ground-based telescopes will be looking for the same planet candidates that TESS discovers. It is also possible that TESS will spot a planet candidate already detected by another telescope in the past. With these combined observations, the planet could then be confirmed. The first planet TESS discovered, Pi Mensae c, orbits a star previously observed with the radial-velocity method on the ground. Scientists compared the TESS data and the radial-velocity data from that star to confirm the presence of planet “c.”

Scientists using the radial-velocity detection method see a star’s wobble caused by a planet’s gravity, and can rule out other kinds of objects such as companion stars. Radial-velocity detection also allows scientists to calculate the mass of the planet.

6. …or at least another telescope.

Other space telescopes may also be used to help confirm exoplanets, characterize them and even discover additional planets around the same stars. If the planet is detected by the same method, but by two different telescopes, and has received enough scrutiny that the scientists are more than 99 percent sure it’s a planet, it is said to be “validated” instead of “confirmed.”

7. Write a paper.

After thoroughly analyzing the data, and running tests to make sure that their result still looks like the signature of a planet, scientists write a formal paper describing their findings. Using the transit method, they can also report the size of the planet. The planet’s radius is related to how much light it blocks from the star, as well as the size of the star itself. The scientists then submit the study to a journal.

8. Wait for peer review.

Scientific journals have a rigorous peer review process. This means scientific experts not involved in the study review it and make sure the findings look sound. The peer-reviewers may have questions or suggestions for the scientists. When everyone agrees on a version of the study, it gets published.

9. Publish the study.

When the study is published, scientists can officially say they have found a new planet. This may still not be the end of the story, however. For example, the TRAPPIST telescope in Chile first thought they had discovered three Earth-size planets in the TRAPPIST-1 system. When our Spitzer Space Telescope and other ground-based telescopes followed up, they found that one of the original reported planets (the original TRAPPIST-1d) did not exist, but they discovered five others --bringing the total up to seven wondrous rocky worlds.

10. Catalog and celebrate -- and look closer if you can!

Confirmed planets get added to our official catalog. So far, Kepler has sent back the biggest bounty of confirmed exoplanets of any telescope -- more than 2,600 to date. TESS, which just began its planet search, is expected to discover many thousands more. Ground-based follow-up will help determine if these planets are gaseous or rocky, and possibly more about their atmospheres. The forthcoming James Webb Space Telescope will be able to take a deeper look at the atmospheres of the most interesting TESS discoveries.

Scientists sometimes even uncover planets with the help of people like you: exoplanet K2-138 was discovered through citizen scientists in Kepler’s K2 mission data. Based on surveys so far, scientists calculate that almost every star in the Milky Way should have at least one planet. That makes billions more, waiting to be found! Stay up to date with our latest discoveries using this exoplanet counter.

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Solar System 10 Things: Spitzer Space Telescope

Our Spitzer Space Telescope is celebrating 15 years since its launch on August 25, 2003. This remarkable spacecraft has made discoveries its designers never even imagined, including some of the seven Earth-size planets of TRAPPIST-1. Here are some key facts about Spitzer:

1. Spitzer is one of our Great Observatories.

Our Great Observatory Program aimed to explore the universe with four large space telescopes, each specialized in viewing the universe in different wavelengths of light. The other Great Observatories are our Hubble Space Telescope, Chandra X-Ray Observatory, and Compton Gamma-Ray Observatory. By combining data from different kinds of telescopes, scientists can paint a fuller picture of our universe.

2. Spitzer operates in infrared light.

Infrared wavelengths of light, which primarily come from heat radiation, are too long to be seen with human eyes, but are important for exploring space — especially when it comes to getting information about something extremely far away. From turbulent clouds where stars are born to small asteroids close to Earth’s orbit, a wide range of phenomena can be studied in infrared light. Objects too faint or distant for optical telescopes to detect, hidden by dense clouds of space dust, can often be seen with Spitzer. In this way, Spitzer acts as an extension of human vision to explore the universe, near and far.

What’s more, Spitzer doesn’t have to contend with Earth’s atmosphere, daily temperature variations or day-night cycles, unlike ground-based telescopes. With a mirror less than 1 meter in diameter, Spitzer in space is more sensitive than even a 10-meter-diameter telescope on Earth.

3. Spitzer was the first spacecraft to fly in an Earth-trailing orbit.

Rather than circling Earth, as Hubble does, Spitzer orbits the Sun on almost the same path as Earth. But Spitzer moves slower than Earth, so the spacecraft drifts farther away from our planet each year.

This “Earth-trailing orbit” has many advantages. Being farther from Earth than a satellite, it receives less heat from our planet and enjoys a naturally cooler environment. Spitzer also benefits from a wider view of the sky by orbiting the Sun. While its field of view changes throughout the year, at any given time it can see about one-third of the sky. Our Kepler space telescope, famous for finding thousands of exoplanets – planets outside our solar system -- also settled in an Earth-trailing orbit six years after Spitzer.

4. Spitzer began in a “cold mission.”

Spitzer has far outlived its initial requirement of 2.5 years. The Spitzer team calls the first 5.5 years “the cold mission” because the spacecraft’s instruments were deliberately cooled down during that time. Liquid helium coolant kept Spitzer’s instruments just a few degrees above absolute zero (which is minus 459 degrees Fahrenheit, or minus 273 degrees Celsius) in this first part of the mission.

5. The “warm mission” was still pretty cold.

Spitzer entered what was called the “warm mission” when the 360 liters of liquid helium coolant that was chilling its instruments ran out in May 2009.

At the “warm” temperature of minus 405 Fahrenheit, two of Spitzer's instruments -- the Infrared Spectrograph (IRS) and Multiband Imaging Photometer (MIPS) -- stopped working. But two of the four detector arrays in the Infrared Array Camera (IRAC) persisted. These “channels” of the camera have driven Spitzer’s explorations since then.

6. Spitzer wasn’t designed to study exoplanets, but made huge strides in this area.

Exoplanet science was in its infancy in 2003 when Spitzer launched, so the mission’s first scientists and engineers had no idea it could observe planets beyond our solar system. But the telescope’s accurate star-targeting system and the ability to control unwanted changes in temperature have made it a useful tool for studying exoplanets. During the Spitzer mission, engineers have learned how to control the spacecraft’s pointing more precisely to find and characterize exoplanets, too.

Using what’s called the “transit method,” Spitzer can stare at a star and detect periodic dips in brightness that happen when a planet crosses a star’s face. In one of its most remarkable achievements, Spitzer discovered three of the TRAPPIST-1 planets and confirmed that the system has seven Earth-sized planets orbiting an ultra-cool dwarf star. Spitzer data also helped scientists determine that all seven planets are rocky, and made these the best-understood exoplanets to date.

Spitzer can also use a technique called microlensing to find planets closer to the center of our galaxy. When a star passes in front of another star, the gravity of the first star can act as a lens, making the light from the more distant star appear brighter. Scientists are using microlensing to look for a blip in that brightening, which could mean that the foreground star has a planet orbiting it. Microlensing could not have been done early in the mission when Spitzer was closer to Earth, but now that the spacecraft is farther away, it has a better chance of measuring these events.

7. Spitzer is a window into the distant past.

The spacecraft has observed and helped discover some of the most distant objects in the universe, helping scientists understand where we came from. Originally, Spitzer’s camera designers had hoped the spacecraft would detect galaxies about 12 billion light-years away. In fact, Spitzer has surpassed that, and can see even farther back in time – almost to the beginning of the universe. In collaboration with Hubble, Spitzer helped characterize the galaxy GN-z11 about 13.4 billion light-years away, whose light has been traveling since 400 million years after the big bang. It is the farthest galaxy known.

8. Spitzer discovered Saturn’s largest ring.

Everyone knows Saturn has distinctive rings, but did you know its largest ring was only discovered in 2009, thanks to Spitzer? Because this outer ring doesn’t reflect much visible light, Earth-based telescopes would have a hard time seeing it. But Spitzer saw the infrared glow from the cool dust in the ring. It begins 3.7 million miles (6 million kilometers) from Saturn and extends about 7.4 million miles (12 million kilometers) beyond that.

9. The “Beyond Phase” pushes Spitzer to new limits.

In 2016, Spitzer entered its “Beyond phase,” with a name reflecting how the spacecraft operates beyond its original scope.

As Spitzer floats away from Earth, its increasing distance presents communication challenges. Engineers must point Spitzer’s antenna at higher angles toward the Sun in order to talk to our planet, which exposes the spacecraft to more heat. At the same time, the spacecraft’s solar panels receive less sunlight because they point away from the Sun, putting more stress on the battery.

The team decided to override some autonomous safety systems so Spitzer could continue to operate in this riskier mode. But so far, the Beyond phase is going smoothly.

10. Spitzer paves the way for future infrared telescopes.

Spitzer has identified areas of further study for our upcoming James Webb Space Telescope, planned to launch in 2021. Webb will also explore the universe in infrared light, picking up where Spitzer eventually will leave off. With its enhanced ability to probe planetary atmospheres, Webb may reveal striking new details about exoplanets that Spitzer found. Distant galaxies unveiled by Spitzer together with other telescopes will also be observed in further detail by Webb. The space telescope we are planning after that, WFIRST, will also investigate long-standing mysteries by looking at infrared light. Scientists planning studies with future infrared telescopes will naturally build upon the pioneering legacy of Spitzer.

Read the web version of this week’s “Solar System: 10 Things to Know” article HERE. 

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10 Ways to BBQ on an Alien World

There are over 3,700 planets in our galaxy. Many of them orbit stars outside our solar system, these are known as exoplanets. Spend a summer weekend barbecuing it up on any of these alien worlds.

(WARNING: Don't try any of this on Earth—except the last one.)

1. Lava World

Janssen aka 55 Cancri e

Hang your steak on a fishing pole and dangle your meat over the boiling pools of lava on this possible magma world. Try two to three minutes on each side to get an ashy feast of deliciousness.

2. Hot Jupiter

Dimidium aka 51 Pegasi b

Set your grill to 1800 degrees Fahrenheit (982 degrees Celsius) or hop onto the first exoplanet discovered and get a perfect char on your hot dogs. By the time your dogs are done, it’ll be New Year’s Eve, because a year on this planet is only four days long.

3. Super Earth

HD 40307 g

Super air fry your duck on this Super Earth, as you skydive in the intense gravity of a planet twice as massive as Earth. Why are you air frying a duck? We don’t know. Why are you skydiving on an exoplanet? We’re not judging.

4. Lightning Neptune

HAT-P-11b

I’ve got steaks, they’re multiplying/and I’m looooosing control. Cause the power this planet is supplying/is electrifying!

Sear your tuna to perfection in the lightning strikes that could flash across the stormy skies of this Neptune-like planet named HAT-P-11b.

5. Red Earth

Kepler-186f

Tired of all that meat? Try a multi-colored salad with the vibrant plants that could grow under the red sun of this Earth-sized planet. But it could also be a lifeless rock, so BYOB (bring your own barbecue).

6. Inferno World

Kepler-70b

Don’t take too long to prep your vegetables for the grill! The hottest planet on record will flash-incinerate your veggies in seconds!

7. Egg-shaped

WASP-12b

Picture this: You are pressure cooking your chicken on a hot gas giant in the shape of an egg. And you’re under pressure to cook fast, because this gas giant is being pulled apart by its nearby star.

8. Two suns

Kepler-16b

Evenly cook your ribs in a dual convection oven under the dual stars of this “Tatooine.” Kick back and watch your two shadows grow in the fading light of a double sunset.

9. Takeout

Venus

Order in for a staycation in our own solar system. The smell of rotten eggs rising from the clouds of sulfuric acid and choking carbon dioxide will put you off cooking, so get that meal to go.

10. Take a Breath

Earth

Sometimes the best vacations are the ones you take at home. Flip your burgers on the only planet where you can breathe the atmosphere.

Grill us on Twitter and tell us how bad our jokes are.

Read the full version of this week’s ‘Solar System: 10 Things to Know’ Article HERE.

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The Hunt for New Worlds Continues with TESS

We're getting ready to start our next mission to find new worlds! The Transiting Exoplanet Survey Satellite (TESS) will find thousands of planets beyond our solar system for us to study in more detail. It's preparing to launch from our Kennedy Space Center at Cape Canaveral in Florida.

Once it launches, TESS will look for new planets that orbit bright stars relatively close to Earth. We're expecting to find giant planets, like Jupiter, but we're also predicting we'll find Earth-sized planets. Most of those planets will be within 300 light-years of Earth, which will make follow-up studies easier for other observatories.

TESS will find these new exoplanets by looking for their transits. A transit is a temporary dip in a star's brightness that happens with predictable timing when a planet crosses between us and the star. The information we get from transits can tell us about the size of the planet relative to the size of its star. We've found nearly 3,000 planets using the transit method, many with our Kepler space telescope. That's over 75% of all the exoplanets we've found so far!

TESS will look at nearly the entire sky (about 85%) over two years. The mission divides the sky into 26 sectors. TESS will look at 13 of them in the southern sky during its first year before scanning the northern sky the year after.

What makes TESS different from the other planet-hunting missions that have come before it? The Kepler mission (yellow) looked continually at one small patch of sky, spotting dim stars and their planets that are between 300 and 3,000 light-years away. TESS (blue) will look at almost the whole sky in sections, finding bright stars and their planets that are between 30 and 300 light-years away.

TESS will also have a brand new kind of orbit (visualized below). Once it reaches its final trajectory, TESS will finish one pass around Earth every 13.7 days (blue), which is half the time it takes for the Moon (gray) to orbit. This position maximizes the amount of time TESS can stare at each sector, and the satellite will transmit its data back to us each time its orbit takes it closest to Earth (orange).

Kepler's goal was to figure out how common Earth-size planets might be. TESS's mission is to find exoplanets around bright, nearby stars so future missions, like our James Webb Space Telescope, and ground-based observatories can learn what they're made of and potentially even study their atmospheres. TESS will provide a catalog of thousands of new subjects for us to learn about and explore.

The TESS mission is led by MIT and came together with the help of many different partners. Learn more about TESS and how it will further our knowledge of exoplanets, or check out some more awesome images and videos of the spacecraft. And stay tuned for more exciting TESS news as the spacecraft launches!

Watch the Launch!

*April 16 Update*

Launch teams are standing down today to conduct additional Guidance Navigation and Control analysis, and teams are now working towards a targeted launch of the Transiting Exoplanet Survey Satellite (TESS) on Wednesday, April 18. The TESS spacecraft is in excellent health, and remains ready for launch. TESS will launch on a Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida.

For more information and updates, visit: https://blogs.nasa.gov/tess/

Live Launch Coverage!

TESS is now slated to launch on Wednesday, April 18 on a SpaceX Falcon 9 rocket from our Kennedy Space Center in Florida.

Watch HERE.

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Solar System: 10 Things to Know This Week

Planets Outside Our Solar System

Let the planet-hunting begin!

Our Transiting Exoplanet Survey Satellite (TESS), which will scan the skies to look for planets beyond our solar system—known as exoplanets—is now in Florida to begin preparations for launch in April. Below, 10 Things to know about the many, many unknown planets out there awaiting our discovery.

1—Exo-what?

We call planets in our solar system, well, planets, but the many planets we’re starting to discover outside of our solar system are called exoplanets. Basically, they’re planets that orbit another star.

2—All eyes on TRAPPIST-1.

Remember the major 2016 announcement that we had discovered seven planets 40 light-years away, orbiting a star called TRAPPIST-1? Those are all exoplanets. (Here’s a refresher.)

3—Add 95 new ones to that.

Just last month, our Kepler telescope discovered 95 new exoplanets beyond our solar system (on top of the thousands of exoplanets Kepler has discovered so far). The total known planet count beyond our solar system is now more than 3,700. The planets range in size from mostly rocky super-Earths and fluffy mini-Neptunes, to Jupiter-like giants. They include a new planet orbiting a very bright star—the brightest star ever discovered by Kepler to have a transiting planet.

4—Here comes TESS.

How many more exoplanets are out there waiting to be discovered? TESS will monitor more than 200,000 of the nearest and brightest stars in search of transit events—periodic dips in a star’s brightness caused by planets passing in front—and is expected to find thousands of exoplanets.

5—With a sidekick, too.

Our upcoming James Webb Space Telescope, will provide important follow-up observations of some of the most promising TESS-discovered exoplanets. It will also allow scientists to study their atmospheres and, in some special cases, search for signs that these planets could support life.

6—Prepped for launch.

TESS is scheduled to launch on a SpaceX Falcon 9 rocket from Cape Canaveral Air Force Station nearby our Kennedy Space Center in Florida, no earlier than April 16, pending range approval.

7—A groundbreaking find.

In 1995, 51 Pegasi b (also called "Dimidium") was the first exoplanet discovered orbiting a star like our Sun. This find confirmed that planets like the ones in our solar system could exist elsewhere in the universe.

8—Trillions await.

A recent statistical estimate places, on average, at least one planet around every star in the galaxy. That means there could be a trillion planets in our galaxy alone, many of them in the range of Earth’s size.

9—Signs of life.

Of course, our ultimate science goal is to find unmistakable signs of current life. How soon can that happen? It depends on two unknowns: the prevalence of life in the galaxy and a bit of luck. Read more about the search for life.

10—Want to explore the galaxy?

No need to be an astronaut. Take a trip outside our solar system with help from our Exoplanet Travel Bureau.

Read the full version of this week’s ‘10 Things to Know’ article HERE. 

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Are we alone in the universe?

There’s never been a better time to ponder this age-old question. We now know of thousands of exoplanets – planets that orbit stars elsewhere in the universe.

So just how many of these planets could support life?

Scientists from a variety of fields — including astrophysics, Earth science, heliophysics and planetary science — are working on this question. Here are a few of the strategies they’re using to learn more about the habitability of exoplanets.

Squinting at Earth

Even our best telescopic images of exoplanets are still only a few pixels in size. Just how much information can we extract from such limited data? That’s what Earth scientists have been trying to figure out.

One group of scientists has been taking high-resolution images of Earth from our Earth Polychromatic Imaging Camera and ‘degrading’ them in order to match the resolution of our pixelated exoplanet images. From there, they set about a grand process of reverse-engineering: They try to extract as much accurate information as they can from what seems — at first glance — to be a fairly uninformative image.

Credits: NOAA/NASA/DSCOVR

So far, by looking at how Earth’s brightness changes when land versus water is in view, scientists have been able to reverse-engineer Earth's albedo (the proportion of solar radiation it reflects), its obliquity (the tilt of its axis relative to its orbital plane), its rate of rotation, and even differences between the seasons. All of these factors could potentially influence a planet’s ability to support life.

Avoiding the “Venus Zone”

In life as in science, even bad examples can be instructive. When it comes to habitability, Venus is a bad example indeed: With an average surface temperature of 850 degrees Fahrenheit, an atmosphere filled with sulfuric acid, and surface pressure 90 times stronger than Earth’s, Venus is far from friendly to life as we know it.

The surface of Venus, imaged by Soviet spacecraft Venera 13 in March 1982

Since Earth and Venus are so close in size and yet so different in habitability, scientists are studying the signatures that distinguish Earth from Venus as a tool for differentiating habitable planets from their unfriendly look-alikes.

Using data from our Kepler Space Telescope, scientists are working to define the “Venus Zone,” an area where planetary insolation – the amount of light a given planet receives from its host star -- plays a key role in atmospheric erosion and greenhouse gas cycles.

Planets that appear similar to Earth, but are in the Venus Zone of their star, are, we think, unlikely to be able to support life.

Modeling Star-Planet Interactions

When you don’t know one variable in an equation, it can help to plug in a reasonable guess and see how things work out. Scientists used this process to study Proxima b, our closest exoplanet neighbor. We don’t yet know whether Proxima b, which orbits the red dwarf star Proxima Centauri four light-years away, has an atmosphere or a magnetic field like Earth’s. However, we can estimate what would happen if it did.

The scientists started by calculating the radiation emitted by Proxima Centauri based on observations from our Chandra X-ray Observatory. Given that amount of radiation, they estimated how much atmosphere Proxima b would be likely to lose due to ionospheric escape — a process in which the constant outpouring of charged stellar material strips away atmospheric gases.

With the extreme conditions likely to exist at Proxima b, the planet could lose the equivalent of Earth’s entire atmosphere in 100 million years — just a fraction of Proxima b’s 4-billion-year lifetime. Even in the best-case scenario, that much atmospheric mass escapes over 2 billion years. In other words, even if Proxima b did at one point have an atmosphere like Earth, it would likely be long gone by now.

Imagining Mars with a Different Star

We think Mars was once habitable, supporting water and an atmosphere like Earth’s. But over time, it gradually lost its atmosphere – in part because Mars, unlike Earth, doesn’t have a protective magnetic field, so Mars is exposed to much harsher radiation from the Sun's solar wind.

But as another rocky planet at the edge of our solar system’s habitable zone, Mars provides a useful model for a potentially habitable planet. Data from our Mars Atmosphere and Volatile Evolution, or MAVEN, mission is helping scientists answer the question: How would Mars have evolved if it were orbiting a different kind of star?

Scientists used computer simulations with data from MAVEN to model a Mars-like planet orbiting a hypothetical M-type red dwarf star. The habitable zone of such a star is much closer than the one around our Sun.

Being in the habitable zone that much closer to a star has repercussions. In this imaginary situation, the planet would receive about 5 to 10 times more ultraviolet radiation than the real Mars does, speeding up atmospheric escape to much higher rates and shortening the habitable period for the planet by a factor of about 5 to 20.

These results make clear just how delicate a balance needs to exist for life to flourish. But each of these methods provides a valuable new tool in the multi-faceted search for exoplanet life.  Armed with these tools, and bringing to bear a diversity of scientific perspectives, we are better positioned than ever to ask: are we alone?

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Researchers Just Found (For The First Time) An 8th Planet Orbiting A Star Far, Far Away

Our Milky Way galaxy is full of hundreds of billions of worlds just waiting to be found. In 2014, scientists using data from our planet-hunting Kepler space telescope discovered seven planets orbiting Kepler-90, a Sun-like star located 2,500 light-years away. Now, an eighth planet has been identified in this planetary system, making it tied with our own solar system in having the highest number of known planets. Here’s what you need to know:

The new planet is called Kepler-90i.

Kepler-90i is a sizzling hot, rocky planet. It’s the smallest of eight planets in the Kepler-90 system. It orbits so close to its star that a “year” passes in just 14 days.

Average surface temperatures on Kepler-90i are estimated to hover around 800 degrees Fahrenheit, making it an unlikely place for life as we know it.

Its planetary system is like a scrunched up version of our solar system.

The Kepler-90 system is set up like our solar system, with the small planets located close to their star and the big planets farther away. This pattern is evidence that the system’s outer gas planets—which are about the size of Saturn and Jupiter—formed in a way similar to our own.

But the orbits are much more compact. The orbits of all eight planets could fit within the distance of Earth’s orbit around our Sun! Sounds crowded, but think of it this way: It would make for some great planet-hopping.

Kepler-90i was discovered using machine learning.

Most planets beyond our solar system are too far away to be imaged directly. The Kepler space telescope searches for these exoplanets—those planets orbiting stars beyond our solar system—by measuring how the brightness of a star changes when a planet transits, or crosses in front of its disk. Generally speaking, for a given star, the greater the dip in brightness, the bigger the planet!

Researchers trained a computer to learn how to identify the faint signal of transiting exoplanets in Kepler’s vast archive of deep-space data. A search for new worlds around 670 known multiple-planet systems using this machine-learning technique yielded not one, but two discoveries: Kepler-90i and Kepler-80g. The latter is part of a six-planet star system located 1,000 light-years away.

This is just the beginning of a new way of planet hunting.

Kepler-90 is the first known star system besides our own that has eight planets, but scientists say it won’t be the last. Other planets may lurk around stars surveyed by Kepler. Next, researchers are using machine learning with sophisticated computer algorithms to search for more planets around 150,000 stars in the Kepler database.

In the meantime, we’ll be doing more searching with telescopes.

Kepler is the most successful planet-hunting spacecraft to date, with more than 2,500 confirmed exoplanets and many more awaiting verification. Future space missions, like the Transiting Exoplanet Survey Satellite (TESS), the James Webb Space Telescope and Wide-Field Infrared Survey Telescope (WFIRST) will continue the search for new worlds and even tell us which ones might offer promising homes for extraterrestrial life.

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*All images of exoplanets are artist illustrations.

What in the Universe is an Exoplanet?

Simply put, an exoplanet is a planet that orbits another star. 

All of the planets in our solar system orbit around the Sun. Planets that orbit around other stars outside our solar system are called exoplanets.

Just because a planet orbits a star (like Earth) does not mean that it is automatically stable for life. The planet must be within the habitable zone, which is the area around a star in which water has the potential to be liquid…aka not so close that all the water would evaporate, and not too far away where all the water would freeze.

Exoplanets are very hard to see directly with telescopes. They are hidden by the bright glare of the stars they orbit. So, astronomers use other ways to detect and study these distant planets by looking at the effects these planets have on the stars they orbit.

One way to search for exoplanets is to look for "wobbly" stars. A star that has planets doesn’t orbit perfectly around its center. From far away, this off-center orbit makes the star look like it’s wobbling. Hundreds of planets have been discovered using this method. However, only big planets—like Jupiter, or even larger—can be seen this way. Smaller Earth-like planets are much harder to find because they create only small wobbles that are hard to detect.

How can we find Earth-like planets in other solar systems?

In 2009, we launched a spacecraft called Kepler to look for exoplanets. Kepler looked for planets in a wide range of sizes and orbits. And these planets orbited around stars that varied in size and temperature.

Kepler detected exoplanets using something called the transit method. When a planet passes in front of its star, it’s called a transit. As the planet transits in front of the star, it blocks out a little bit of the star's light. That means a star will look a little less bright when the planet passes in front of it. Astronomers can observe how the brightness of the star changes during a transit. This can help them figure out the size of the planet.

By studying the time between transits, astronomers can also find out how far away the planet is from its star. This tells us something about the planet’s temperature. If a planet is just the right temperature, it could contain liquid water—an important ingredient for life.

So far, thousands of planets have been discovered by the Kepler mission.

We now know that exoplanets are very common in the universe. And future missions have been planned to discover many more!

Next month, we’re launching an explorer-class planet finder — the Transiting Exoplanet Survey Satellite (TESS). This mission will search the entire sky for exoplanets — planets outside our solar system that orbit sun-like stars.

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Solar System: 10 Things to Know This Week...Halloween Edition!

This week, we're getting into the Halloween spirit with 10 spooktacular things to let your imagination run wild. 

It's not Halloween without our favorite scary characters, but what if they could stop bothering us Earthlings and go far, far away? We begin with where Dracula, Frankenstein, and other creepy creatures might choose to live if the galaxy were theirs to claim...

1. The dark (k)night.

The prince of darkness himself, Dracula, can finally seek sweet respite from the Sun. We think he'd love to live on a rocky planet named YZ Ceti d that orbits so close to its red star that it's tidally locked keeping one side of the planet in perpetual nighttime and the other side in perpetual daytime, with a brilliant red sky (though we can guess which side Dracula will prefer). 

2. Where art thou, werewolves? 

Home sweet home for our furry Full Moon friends might just be on Trappist-1, a planetary system with seven planets—and where standing on one planet would mean the other planets look like six moons (some as big as our Moon in the sky). 

3. Left in the dust. 

We couldn't think of anyone better to live on Proxima b than The Mummy. Hopefully this ancient monster can finally rest in peace on an exoplanet that scientists theorize is a desert planet once home to ancient oceans. 

4. Cloudy with a chance of Frankenstein.

One scientific experiment we'd like to conduct: whether Frankenstein would rather live on HAT-P-11b or Kepler-3b, theorized to have fierce thunderstorms and lightning. 

5. The walking dead. 

We're pretty confident that if zombies were to pick a planet, they'd want one that shares their love of death and destruction. We think they'd feel right at home on one of the pulsar planets, which are scorched by radiation because they orbit a dead star. 

6. Rest your weary bones. 

Skeletons need look no further: Osiris, an exoplanet that's so close to a star that it's "losing its flesh" as the star destroys it, seems like a perfect match. 

7. Enough of the scary stuff. 

For kids out there, turn pumpkin decorating into an out-of-this-world activity with space-themed stencils, from Saturn to the Sun. 

8. Spooky sounds. 

Cassini's radio emissions from Saturn could give creaky doors and howling winds a run for their money. Listen to the eerie audio recordings here and find more HERE.

9. Pumpkin-carve like a NASA engineer. 

NASA engineers design and build robots that can fly millions of miles to study other planets for a living—so on Halloween, they can't help but bring that creative thinking to the grand old tradition of pumpkin carving. Take a cue from their creations with these insider tips.

10. Detective for a day. 

From blades of ice on Pluto to a fuzzy, white "bunny" photographed on Mars, become a solar system sleuth and see if you can solve the stellar mysteries in this slideshow (then compare with how scientists cracked the case). 

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We Just Identified More Than 200 New (Potential) Planets

The Kepler space telescope is our first mission capable of identifying Earth-size planets around other stars. On Monday, June 19, 2017, scientists from many countries gathered at our Ames Research Center to talk about the latest results from the spacecraft, which include the identification of more than 200 potential new worlds! Here’s what you need to know:

We found 219 new planet candidates.

All of these worlds were found in a patch of sky near the Cygnus constellation in our Milky Way galaxy. Between 2009 and 2013, Kepler searched more than 200,000 stars in the region for orbiting planets. The 219 new planet candidates are part of the more than 4,000 planet candidates and 2,300 confirmed planets Kepler has identified to date.

Ten of these worlds are like our own.

Out of the 219 new planet candidates, 10 are possibly rocky, terrestrial worlds and orbit their star in the habitable zone – the range of distances from a star where liquid water could pool on the surface of a rocky planet.

Small planets come in two sizes.

Kepler has opened up our eyes to the existence of many small worlds. It turns out a lot of these planets are either approximately 1.5 times the size of Earth or just smaller than Neptune. The cool names given to planets of these sizes? Super Earths and mini-Neptunes.

Some of the new planets could be habitable. 

Water is a key ingredient to life as we know it. Many of the new planet candidates are likely to have small rocky cores enveloped by a thick atmosphere of hydrogen and helium, and some are thought to be ocean worlds. That doesn’t necessarily mean the oceans of these planets are full of water, but we can dream, can’t we?

Other Earths are out there.

Kepler’s survey has made it possible for us to measure the number of Earth-size habitable zone planets in our galaxy. Determining how many planets like our own that exist is the big question we’ll explore next.

The hunt for new planets continues.

Kepler continues to search for planets in different regions of space. With the launch of our Transiting Exoplanet Survey Satellite (TESS) and the James Webb Space Telescope (JWST) in 2018, we’re going to search for planets nearest the sun and measure the composition of their atmospheres. In the mid-2020s, we have our sights on taking a picture of small planets like Earth with our Wide-Field Infrared Survey Telescope (WFIRST).

*All images of planets are artist illustrations.

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It’s May the 4th: Are Star Wars Planets Real?

Look at what we’ve found so far.

Is your favorite Star Wars planet a desert world or an ice planet or a jungle moon?

It’s possible that your favorite planet exists right here in our galaxy. Astronomers have found over 3,700 planets around other stars, called “exoplanets.”

Some of these alien worlds could be very similar to arid Tatooine, watery Scarif and even frozen Hoth, according to our scientists.

Find out if your planet exists in a galaxy far, far away or all around you. And May the Fourth be with you!

Planets With Two Suns

From Luke Skywalker’s home world Tatooine, you can stand in the orange glow of a double sunset. The same could said for Kepler-16b, a cold gas giant roughly the size of Saturn, that orbits two stars. Kepler-16b was the Kepler telescope’s first discovery of a planet in a “circumbinary” orbit (that is, circling both stars, as opposed to just one, in a double star system). 

The best part is that Tatooine aka Kepler-16b was just the first. It has family. A LOT of family. Half the stars in our galaxy are pairs, rather than single stars like our sun. If every star has at least one planet, that’s billions of worlds with two suns. Billions! Maybe waiting for life to be found on them.

Desert Worlds

Mars is a cold desert planet in our solar system, and we have plenty of examples of scorching hot planets in our galaxy (like Kepler-10b), which orbits its star in less than a day)! Scientists think that if there are other habitable planets in the galaxy, they’re more likely to be desert planets than ocean worlds. That’s because ocean worlds freeze when they’re too far from their star, or boil off their water if they’re too close, potentially making them unlivable. Perhaps, it’s not so weird that both Luke Skywalker and Rey grew up on planets that look a lot alike.

Ice Planets

An icy super-Earth named OGLE-2005-BLG-390Lb reminded scientists so much of the frozen Rebel base they nicknamed it “Hoth,” after its frozen temperature of minus 364 degrees Fahrenheit. Another Hoth-like planet was discovered in April 2017; an Earth-mass icy world orbiting its star at the same distance as Earth orbits the sun. But its star is so faint, the surface of OGLE-2016-BLG-1195Lb is probably colder than Pluto.

Forest worlds

Both the forest moon of Endor and Takodana, the home of Han Solo’s favorite cantina in “Force Awakens,” are green like our home planet. But astrobiologists think that plant life on other worlds could be red, black, or even rainbow-colored!

In February 2017, the Spitzer Space Telescope discovered seven Earth-sized planets in the same system, orbiting the tiny red star TRAPPIST-1.

The light from a red star, also known as an M dwarf, is dim and mostly in the infrared spectrum (as opposed to the visible spectrum we see with our sun). And that could mean plants with wildly different colors than what we’re used to seeing on Earth. Or, it could mean animals that see in the near-infrared.

What About Moons?

In Star Wars, Endor, the planet with the cute Ewoks, is actually a habitable moon of a gas giant. Now, we’re looking for life on the moons of our own gas giants. Saturn’s moon Enceladus or Jupiter’s moon Europa are ocean worlds that may well support life. Our Cassini spacecraft explored the Saturn system and its moons, before the mission ended in 2017. Watch the video and learn more about the missions’s findings.

And Beyond

The next few years will see the launch of a new generation of spacecraft to search for planets around other stars. Our TESS spacecraft launched in April 2018, and will discover new exoplanets by the end of the year. The James Webb Space Telescope is slated to launch in 2020. That’s one step closer to finding life.

You might want to take our ‘Star Wars: Fact or Fiction?’ quiz. Try it! Based on your score you may obtain the title of Padawan, Jedi Knight, or even Jedi Master! 

You don’t need to visit a galaxy far, far away to find wondrous worlds. Just visit this one ... there’s plenty to see.

Discover more about exoplanets here: https://exoplanets.nasa.gov/

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Pi Guides the Way

It may be irrational but pi plays an important role in the everyday work of scientists at NASA. 

What Is Pi ?

Pi is the ratio of a circle’s circumference to its diameter. It is also an irrational number, meaning its decimal representation never ends and it never repeats. Pi has been calculated to more than one trillion digits, 

Why March 14?

March 14 marks the yearly celebration of the mathematical constant pi. More than just a number for mathematicians, pi has all sorts of applications in the real world, including on our missions. And as a holiday that encourages more than a little creativity – whether it’s making pi-themed pies or reciting from memory as many of the never-ending decimals of pi as possible (the record is 70,030 digits).

While 3.14 is often a precise enough approximation, hence the celebration occurring on March 14, or 3/14 (when written in standard U.S.  month/day format), the first known celebration occurred in 1988, and in 2009, the U.S. House of Representatives passed a resolution designating March 14 as Pi Day and encouraging teachers and students to celebrate the day with activities that teach students about pi.

5 Ways We Use Pi at NASA

Below are some ways scientists and engineers used pi.

Keeping Spacecraft Chugging Along

Propulsion engineers use pi to determine the volume and surface area of propellant tanks. It’s how they size tanks and determine liquid propellant volume to keep spacecraft going and making new discoveries. 

Getting New Perspectives on Saturn

A technique called pi transfer uses the gravity of Titan’s moon, Titan, to alter the orbit of the Cassini spacecraft so it can obtain different perspectives of the ringed planet.

Learning the Composition of Asteroids

Using pi and the asteroid’s mass, scientists can calculate the density of an asteroid and learn what it’s made of--ice, iron, rock, etc.

Measuring Craters

knowing the circumference, diameter and surface area of a crater can tell scientists a lot about the asteroid or meteor that may have carved it out.

Determining the Size of Exoplanets

Exoplanets are planets that orbit suns other than our own and scientists use pi to search for them. The first step is determining how much the light curve of a planet’s sun dims when a suspected planets passes in front of it.

Want to learn more about Pi? Visit us on Pinterest at: https://www.pinterest.com/nasa/pi-day/

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Largest Batch of Earth-size, Habitable Zone Planets

Our Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in an area called the habitable zone, where liquid water is most likely to exist on a rocky planet.

This exoplanet system is called TRAPPIST-1, named for The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile. In May 2016, researchers using TRAPPIST announced they had discovered three planets in the system.

Assisted by several ground-based telescopes, Spitzer confirmed the existence of two of these planets and discovered five additional ones, increasing the number of known planets in the system to seven.

This is the FIRST time three terrestrial planets have been found in the habitable zone of a star, and this is the FIRST time we have been able to measure both the masses and the radius for habitable zone Earth-sized planets.

All of these seven planets could have liquid water, key to life as we know it, under the right atmospheric conditions, but the chances are highest with the three in the habitable zone.

At about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius. Because they are located outside of our solar system, these planets are scientifically known as exoplanets. To clarify, exoplanets are planets outside our solar system that orbit a sun-like star.

In this animation, you can see the planets orbiting the star, with the green area representing the famous habitable zone, defined as the range of distance to the star for which an Earth-like planet is the most likely to harbor abundant liquid water on its surface. Planets e, f and g fall in the habitable zone of the star.

Using Spitzer data, the team precisely measured the sizes of the seven planets and developed first estimates of the masses of six of them. The mass of the seventh and farthest exoplanet has not yet been estimated.

For comparison…if our sun was the size of a basketball, the TRAPPIST-1 star would be the size of a golf ball.

Based on their densities, all of the TRAPPIST-1 planets are likely to be rocky. Further observations will not only help determine whether they are rich in water, but also possibly reveal whether any could have liquid water on their surfaces.

The sun at the center of this system is classified as an ultra-cool dwarf and is so cool that liquid water could survive on planets orbiting very close to it, closer than is possible on planets in our solar system. All seven of the TRAPPIST-1 planetary orbits are closer to their host star than Mercury is to our sun.

 The planets also are very close to each other. How close? Well, if a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth’s sky.

The planets may also be tidally-locked to their star, which means the same side of the planet is always facing the star, therefore each side is either perpetual day or night. This could mean they have weather patterns totally unlike those on Earth, such as strong wind blowing from the day side to the night side, and extreme temperature changes.

Because most TRAPPIST-1 planets are likely to be rocky, and they are very close to one another, scientists view the Galilean moons of Jupiter – lo, Europa, Callisto, Ganymede – as good comparisons in our solar system. All of these moons are also tidally locked to Jupiter. The TRAPPIST-1 star is only slightly wider than Jupiter, yet much warmer. 

How Did the Spitzer Space Telescope Detect this System?

Spitzer, an infrared telescope that trails Earth as it orbits the sun, was well-suited for studying TRAPPIST-1 because the star glows brightest in infrared light, whose wavelengths are longer than the eye can see. Spitzer is uniquely positioned in its orbit to observe enough crossing (aka transits) of the planets in front of the host star to reveal the complex architecture of the system. 

Every time a planet passes by, or transits, a star, it blocks out some light. Spitzer measured the dips in light and based on how big the dip, you can determine the size of the planet. The timing of the transits tells you how long it takes for the planet to orbit the star.

The TRAPPIST-1 system provides one of the best opportunities in the next decade to study the atmospheres around Earth-size planets. Spitzer, Hubble and Kepler will help astronomers plan for follow-up studies using our upcoming James Webb Space Telescope, launching in 2018. With much greater sensitivity, Webb will be able to detect the chemical fingerprints of water, methane, oxygen, ozone and other components of a planet’s atmosphere.

At 40 light-years away, humans won’t be visiting this system in person anytime soon...that said...this poster can help us imagine what it would be like: 

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House of Horrors: Exoplanet Edition

Astronomers may be closer than ever to discovering a planet that’s habitable like our own, but along the way they’ve discovered some very scary exoplanets – places where conditions are far too harsh for life as we know it to exist.

Okay, but what IS an exoplanet???

We’ve rounded up some of the most frightening, deadly exoplanets, places that make even the scariest haunted house on Earth pale in comparison. Check them out...

Radiation Bath, Anyone?

The exoplanets PSR B1257+12 B, C & D were among the first discovered, and also happened to be three of the weirdest! The entire system is a graveyard, remnants of what used to be a normal, functional solar system before the star blew apart in a giant explosion known as a supernova.

The massive shockwave from the supernova stripped away any atmosphere or living creatures that might have once lived on these planets, leaving behind ghostly, rocky shells, dead planets orbiting the corpse of an extinct star.

Except that the system isn’t completely dead…the remaining core from the old star has become a zombie star called a pulsar. Literally spinning in its grave, it makes a full rotation every 6.22 milliseconds and emits an intense beam of radiation that can be detected from Earth. The star’s unfortunate planets are thus bathed in deadly radiation on a regular basis, making sure that this system remains a cosmic no-man’s land.

A Mighty Wind

The sound of howling wind is a must for any Earth-based haunted house, but weather conditions on HD 189733 b make it a very dangerous place to go trick-or-treating.

At first glance, this exoplanet looks like the typical “hot Jupiter” — a huge gas planet perched dangerously to a burning-hot star, with daytime temperatures around a balmy 1,770 degrees Fahrenheit. This exoplanet is also “tidally locked” in its orbit, which means that the same side of the planet always faces its star.

But when scientists measured the planet’s nighttime temperature, they were shocked to find that it was only 500 degrees cooler. How does the back side of the planet stay so warm?

The answer is wind! Insanely fast, dangerous wind that whisks heat from day-side to night-side at a speed of 4,500 mph, nearly six times the speed of sound! In fact, astronomers estimate that wind speeds might top out at 5,400 mph, conditions that make hurricanes on Earth look like a breezy day at the beach.

Newborn Exoplanet Around Scorching Star

This exoplanet, named K2-33b, is the youngest fully formed exoplanet ever detected. This planet is a bit larger than Neptune and whips tightly around its star every five days. Since this planet sits nearly 10 times closer to its star than Mercury is to our sun, it’s HOT!

No matter how cute you think infants are, this is one baby you’d want to stay away from.

Boil, Boil, Toil and Trouble

The planet HD 209458 b (aka. Osiris - the god of death) has a few things in common with Earth: water vapor, methane and carbon dioxide in its atmosphere, key ingredients for life on our planet. Don’t be fooled, though, because this planet is a rolling cauldron of almost unimaginable heat.

Even the hottest summer days on Earth don’t get as dangerous as the conditions here. A planet that orbits so close to its host star that its atmosphere is literally boiling off, ripped away from the planet as it whips around on its breakneck 3.5-day orbit.

All Alone and Very, Very Cold

While most of the exoplanets found so far are hellishly hot, OGLE-2005-BLG-390L b has the distinction of being extremely cold.

The planet takes about 10 Earth years to orbit its tiny dwarf star, and it’s a chilly trip; the average temperature on this exoplanet is 50 Kelvin, or minus 370 degrees Fahrenheit! A good costume for trick-or-treating on this frigid planet would be a toasty self-heating spacesuit, an oxygen supply, ice skates and plenty of hot cocoa.

Of course, don’t expect to find many houses with candy here, because despite the fact that it’s just a few times bigger than Earth, this exoplanet is an uninhabitable ice ball stuck in a perpetual winter freeze.

A Scorched World

Kepler-10b is a scorched world, orbiting at a distance that’s more than 20 times closer to its star than Mercury is to our own sun. The daytime temperatures are expected to be more than 2,500 degrees Fahrenheit, hotter than lava flows here on Earth. 

Intense radiation from the star has kept the planet from holding onto an atmosphere, but flecks of silicates and iron that have boiled off a molten surface are swept away by the stellar radiation.

Learn more about worlds beyond our solar system at: https://exoplanets.nasa.gov/

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A Space Odyssey: 21 Years of Searching for Another Earth

There are infinite worlds both like and unlike this world of ours. We must believe that in all worlds there are living creatures and plants and other things we see in this world. – Epicurus, c. 300 B.C.

Are we alone? Are there other planets like ours? Does life exist elsewhere in the universe?

These are questions mankind has been asking for years—since the time of Greek philosophers. But for years, those answers have been elusive, if not impossible to find.

The month of October marks the 21st anniversary of the discovery of the first planet orbiting another sun-like star (aka. an exoplanet), 51 Pegasi b or “Dimidium.” Its existence proved that there were other planets in the galaxy outside our solar system.*

Even more exciting is the fact that astronomers are in hot pursuit of the first discovery of an Earth-like exoplanet orbiting a star other than the sun. The discovery of the so-called "blue dot" could redefine our understanding of the universe and our place in it, especially if astronomers can also find signs that life exists on that planet's surface.

Astronomy is entering a fascinating era where we're beginning to answer tantalizing questions that people have pondered for thousands of years.

Are we alone?

In 1584, when the Catholic monk Giordano Bruno asserted that there were "countless suns and countless earths all rotating around their suns," he was accused of heresy.

But even in Bruno's time, the idea of a plurality of worlds wasn't entirely new. As far back as ancient Greece, humankind has speculated that other solar systems might exist and that some would harbor other forms of life.

Still, centuries passed without convincing proof of planets around even the nearest stars.

Are there other planets like ours?

The first discovery of a planet orbiting a star similar to the sun came in 1995. The Swiss team of Michel Mayor and Didier Queloz of Geneva announced that they had found a rapidly orbiting gas world located blisteringly close to the star 51 Pegasi.

This announcement marked the beginning of a flood of discoveries. Exotic discoveries transformed science fiction into science fact:

a pink planet

worlds with two or even three suns

a gas giant as light as Styrofoam

a world in the shape of an egg

a lava planet

But what about another Earth?

Our first exoplanet mission**, Kepler, launched in 2009 and revolutionized how astronomers understand the universe and our place in it. Kepler was built to answer the question—how many habitable planets exist in our galaxy?

And it delivered: Thousands of planet discoveries poured in, providing statistical proof that one in five sun-like stars (yellow, main-sequence G type) harbor Earth-sized planets orbiting in their habitable zones– where it’s possible liquid water could exist on their surface.

Now, our other missions like the Hubble and Spitzer space telescopes point at promising planetary systems (TRAPPIST-1) to figure out whether they are suitable for life as we know it.

Does life exist elsewhere in the universe?

Now that exoplanet-hunting is a mainstream part of astronomy, the race is on to build instruments that can find more and more planets, especially worlds that could be like our own.

Our Transiting Exoplanet Survey Satellite (TESS), set for launch in 2017-2018, will look for super-Earth and Earth-sized planets around stars much closer to home. TESS will find new planets the same way Kepler does—via the transit method—but will cover 400 times the sky area.

The James Webb Space Telescope, to launch in 2018, wil be our most powerful space telescope to date. Webb will use its spectrograph to look at exoplanet atmospheres, searching for signs of life.

We still don’t know where or which planets are in the habitable zones of the nearest stars­ to Earth. Searching out our nearest potentially habitable neighbors will be the next chapter in this unfolding story.

*The first true discovery of extrasolar planets was actually a triplet of dead worlds orbiting the remains of an exploded star, called a pulsar star. Two of three were found by Dr. Alexander Wolszczan in 1992– a full three years before Dimidium’s discovery. But because they are so strange, and can’t support life as we know it, most scientists would reserve the “first” designation for a planet orbiting a normal star.

** The French CoRoT mission, launched in 2006, was the first dedicated exoplanet space mission. It has contributed dozens of confirmed exoplanets to the ranks and boasts a roster of some of the most well-studied planets outside our solar system.

To stay up-to-date on our latest exoplanet discoveries, visit: https://exoplanets.nasa.gov

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TESS: The Planet Hunter

So you’re thinking...who’s TESS? But, it’s more like: WHAT is TESS? 

The Transiting Exoplanet Survey Satellite (TESS) is an explorer-class planet finder that is scheduled to launch in April 2018. This mission will search the entire sky for exoplanets — planets outside our solar system that orbit sun-like stars.

In the first-ever space borne all-sky transit survey, TESS will identify planets ranging from Earth-sized to gas giants, orbiting a wide range of stellar types and orbital distances.

The main goal of this mission is to detect small planets with bright host stars in the solar neighborhood, so that we can better understand these planets and their atmospheres.

TESS will have a full time job monitoring the brightness of more than 200,000 stars during a two year mission. It will search for temporary drops in brightness caused by planetary transits. These transits occur when a planet’s orbit carries it directly in front of its parent star as viewed from Earth (cool GIF below).

TESS will provide prime targets for further, more detailed studies with the James Webb Space Telescope (JWST), as well as other large ground-based and space-based telescopes of the future.

What is the difference between TESS and our Kepler spacecraft?

TESS and Kepler address different questions: Kepler answers "how common are Earth-like planets?" while TESS answers “where are the nearest transiting rocky planets?”

What do we hope will come out of the TESS mission?

The main goal is to find rocky exoplanets with solid surfaces at the right distance from their stars for liquid water to be present on the surface. These could be the best candidates for follow-up observations, as they fall within the “habitable zone” and be at the right temperatures for liquid water on their surface.

TESS will use four cameras to study sections of the sky’s north and south hemispheres, looking for exoplanets. The cameras would cover about 90 percent of the sky by the end of the mission. This makes TESS an ideal follow-up to the Kepler mission, which searches for exoplanets in a fixed area of the sky. Because the TESS mission surveys the entire sky, TESS is expected to find exoplanets much closer to Earth, making them easier for further study.

Stay updated on this planet-hunting mission HERE.

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Worlds That Will Make You Believe Star Wars is Real

The fantastical planets in Star Wars preceded our discovery of real planets outside our solar system…but fiction isn’t too far from the facts. When we send our spacecraft into the solar system and point our telescopes beyond, we often see things that seem taken right out of the Star Wars universe.

Is there a more perfect time than May the 4th to compare real worlds to the ones depicted in Star Wars? 

Probably not...so here are a few:

Mimas

Saturn’s moon, Mimas, has become known as the "Death Star" moon because of how its 80-mile wide Herschel crater creates a resemblance to the Imperial battle station, especially when seen in this view from our Cassini spacecraft. 

Kepler-452b

The most recently revealed exoplanet dubbed as Earth’s bigger, older cousin, Kepler-452b, might make a good stand-in for Coruscant — the high tech world seen in several Star Wars films whose surface is encased in a single, globe-spanning city. Kepler-452b belongs to a star system 1.5 billion years older than Earth’s! That would give any technologically adept species more than a billion-year jump ahead of us.

CoRoT-7b

At 3,600 degrees Fahrenheit, CoRoT-7B is a HOT planet. Discovered in 2010 with France’s CoRoT satellite, it’s some 480 light-years away, and has a diameter 70% larger than Earth’s, with nearly five times the mass. Possibly the boiled-down remnant of a Saturn-sized planet, its orbit is so tight that its star looms much larger in its sky than our sun appears to us, keeping its sun-facing surface molten!  This scorching planet orbiting close to its star could be a good analog for planet Mustafar from Star Wars. 

Kepler-16b

Luke Skywalker’s home planet, Tatooine, is said to possess a harsh, desert environment, swept by sandstorms as it roasts under the glare of twin suns. Real exoplanets in the thrall of two or more suns are even harsher! Kepler-16b was the Kepler telescope’s first discovery of a planet in a “circumbinary” orbit (a.k.a, circling both stars, as opposed to just one, in a double star system). This planet, however, is likely cold, about the size of Saturn, and gaseous, though partly composed of rock.

OGLE-2005-BLG-390

Fictional Hoth is a frozen tundra that briefly serves as a base for the hidden Rebel Alliance. It’s also the nickname of real exoplanet OGLE-2005-BLG-390, a cold super-Earth whose surface temperature clocks in at minus 364 degrees Fahrenheit.

Kepler-22b

Kepler-22b, analog to the Star Wars planet Kamino…which was the birthplace of the army of clone soldiers, is a super-Earth that could be covered in a super ocean. The jury is still out on Kepler-22b’s true nature; at 2.4 times Earth’s radius, it might even be gaseous. But if the ocean world idea turns out to be right, we can envision a physically plausible Kamino-like planet.

Gas Giants

Gas giants of all stripes populate the real exoplanet universe; in Star Wars, a gas giant called Bespin is home to a “Cloud City” actively involved in atmospheric mining. Mining the atmospheres of giant gas planets is a staple of science fiction. We too have examined the question, and found that gases such as helium-3 and hydrogen could theoretically be extracted from the atmospheres of Uranus and Neptune. 

Exomoons

Endor, the forested realm of the Ewoks, orbits a gas giant. Exomoon detection is still in its infancy for scientists on Earth. However, a possible exomoon (a moon circling a distant planet) was observed in 2014 via microlensing. It will remain unconfirmed, however, since each microlensing event can be seen only once.

May the 4th be with you!

Discover more about exoplanets here: https://exoplanets.jpl.nasa.gov/

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A Spacecraft's Second Life: Our K2 mission

A critical failure that ended one mission has borne an unexpected and an exciting new science opportunity. The Kepler spacecraft, known for finding thousands of planets orbiting other stars, has a new job as the K2 mission.

Like its predecessor, K2 detects the tiny, telltale dips in the brightness of a star as an object passes or transits it, to possibly reveal the presence of a planet. Searching close neighboring stars for near-Earth-sized planets, K2 is finding planets ripe for follow-up studies on their atmospheres and to see what the planet is made of. A step up from its predecessor, K2 is revealing new info on comets, asteroids, dwarf planets, ice giants and moons. It will also provide new insight into areas as diverse as the birth of new stars, how stars explode into spectacular supernovae, and even the evolution of black holes.

K2 is expanding the planet-hunting legacy and has ushered in entirely new opportunities in astrophysics research, yet this is only the beginning.

Searching Nearby for Signs of Life

Image credit: ESO/L. Calçada

Scientists are excited about nearby multi-planet system known as K2-3. This planetary system, discovered by K2, is made of three super-Earth-sized planets orbiting a cool M-star (or red dwarf) 135 light-years away, which is relatively close in astronomical terms. To put that distance into perspective, if the Milky Way galaxy was scaled down to the size of the continental U.S. it would be the equivalent of walking the three-mile long Golden Gate Park in San Francisco, California. At this distance, our other powerful space-investigators – the Hubble Space Telescope and the forthcoming James Webb Space Telescope (JWST) – could study the atmospheres of these worlds in search of chemical fingerprints that could be indicative of life. K2 expects to find a few hundred of these close-by, near-Earth-sized neighbors.

K2 won’t be alone in searching for nearby planets outside our solar system. Revving up for launch around 2017-2018, our Transiting Exoplanet Survey Satellite (TESS) plans to monitor 200,000 close stars for planets, with a focus on finding Earth and Super-Earth-sized planets.

The above image is an artist rendering of Gliese 581, a planetary system representative of K2-3.

Neptune's Moon Dance

Movie credit: NASA Ames/SETI Institute/J. Rowe

Spying on our neighbors in our own solar system, K2 caught Neptune in a dance with its moons Triton and Nereid. On day 15 (day counter located in the top right-hand corner of the green frame) of the sped-up movie, Neptune appears, followed by its moon Triton, which looks small and faint. Keen-eyed observers can also spot Neptune's tiny moon Nereid at day 24. Neptune is not moving backward but appears to do so because of the changing position of the Kepler spacecraft as it orbits around the sun. A few fast-moving asteroids make cameo appearances in the movie, showing up as streaks across the K2 field of view. The red dots are a few of the stars K2 examines in its search for transiting planets outside of our solar system. An international team of astronomers is using these data to track Neptune’s weather and probe the planet’s internal structure by studying subtle brightness fluctuations that can only be observed with K2.

Dead Star Devours Planet

Image credit: CfA/Mark A. Garlick

K2 also caught a white dwarf – the dead core of an exploded star –vaporizing a nearby tiny rocky planet. Slowly the planet will disintegrate, leaving a dusting of metals on the surface of the star. This trail of debris blocks a tiny fraction of starlight from the vantage point of the spacecraft producing an unusual, but vaguely familiar pattern in the data. Recognizing the pattern, scientists further investigated the dwarf’s atmosphere to confirm their find. This discovery has helped validate a long-held theory that white dwarfs are capable of cannibalizing possible remnant planets that have survived within its solar system.

Searching for Far Out Worlds

NASA/JPL-Caltech

In April, spaced-based K2 and ground-based observatories on five continents will participate in a global experiment in exoplanet observation and simultaneously monitor the same region of sky towards the center of our galaxy to search for small planets, such as the size of Earth, orbiting very far from their host star or, in some cases, orbiting no star at all. For this experiment, scientists will use gravitational microlensing – the phenomenon that occurs when the gravity of a foreground object focuses and magnifies the light from a distant background star.

The animation demonstrates the principles of microlensing. The observer on Earth sees the source (distant) star when the lens (closer) star and planet pass through the center of the image. The inset shows what may be seen through a ground-based telescope. The image brightens twice, indicating when the star and planet pass through the observatory's line of sight to the distant star.

Full microlensing animation available HERE.

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10 Intriguing Worlds Beyond Our Solar System

In celebration of the 20th anniversary of the first confirmed planet around a sun-like star, a collection of some interesting exoplanets has been put together. Some of these are rocky, some are gaseous and some are very, very cold. But there’s one thing each these strange new worlds have in common: All have advanced scientific understanding of our place in the cosmos. Check out these 10 exoplanets, along with artist’s concepts depicting what they might look like. For an extended list of 20 exoplanets, go HERE. 

1. Kepler-186f

Kepler-186f was the first rocky planet to be found within the habitable zone -- the region around the host star where the temperature is right for liquid water. This planet is also very close in size to Earth. Even though we may not find out what’s going on at the surface of this planet anytime soon, it’s a strong reminder of why new technologies are being developed that will enable scientists to get a closer look at distance worlds. 

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2. HD 209458 b (nickname “Osiris”)

The first planet to be seen in transit (crossing its star) and the first planet to have it light directly detected. The HD 209458 b transit discovery showed that transit observations were feasible and opened up an entire new realm of exoplanet characterization.

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3. Kepler-11 system

This was the first compact solar system discovered by Kepler, and it revealed that a system can be tightly packed, with at least five planets within the orbit of Mercury, and still be stable. It touched off a whole new look into planet formation ideas and suggested that multiple small planet systems, like ours, may be common.

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4. Kepler-16b

A real-life "Tatooine," this planet was Kepler's first discovery of a planet that orbits two stars -- what is known as a circumbinary planet.

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5. 51 Pegasi b

This giant planet, which is about half the mass of Jupiter and orbits its star every four days, was the first confirmed exoplanet around a sun-like star, a discovery that launched a whole new field of exploration.

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6. CoRoT 7b

The first super-Earth identified as a rocky exoplanet, this planet proved that worlds like the Earth were indeed possible and that the search for potentially habitable worlds (rocky planets in the habitable zone) might be fruitful.

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7. Kepler-22b

A planet in the habitable zone and a possible water-world planet unlike any seen in our solar system.

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8. Kepler-10b

Kepler's first rocky planet discovery is a scorched, Earth-size world that scientists believe may have a lava ocean on its surface.

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9. Kepler-444 system

The oldest known planetary system has five terrestrial-sized planets, all in orbital resonance. This weird group showed that solar systems have formed and lived in our galaxy for nearly its entire existence.

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10. 55 Cancri e

Sauna anyone? 55 Cancri e is a toasty world that rushes around its star every 18 hours. It orbits so closely -- about 25 times closer than Mercury is to our sun -- that it is tidally locked with one face forever blistering under the heat of its sun. The planet is proposed to have a rocky core surrounded by a layer of water in a “supercritical” state, where it is both liquid and gas, and then the whole planet is thought to be topped by a blanket of steam. 

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An Exo-What...?

Simply put, an exoplanet is a planet that orbits another star. That said, just because a planet orbits a star (like Earth) does not mean that it is automatically stable for life. The planet must be within the habitable zone, which is the area around a star in which water has the potential to be liquid…aka not so close that all the water would evaporate, and not too far away where all the water would freeze.

Recently, with the help of our Kepler spacecraft, scientists have discovered the most Earth-like exoplanet ever, Kepler-452b. Pretty cool! This chart shows 12 other exoplanet discoveries that are less than twice the size of Earth, and live in the habitable zone of their host star. Kepler-452b is special because all previous findings have orbited stars that are smaller and cooler than Earth’s.

You may be thinking, “Okay, so what? There’s an Earth-like planet that spins around a similar sized sun.” Well, Kepler-452b orbits its sun at nearly the same distance from its star as Earth does from our sun, which means that conditions on the plant could be similar to those here on Earth!

We can already guess your next question…”When are we going to Kepler-452b?!” Well, this planet is located in the constellation Cygnus which is 1,400 light-years away, so not anytime soon. However, our Kepler spacecraft continues to search for Earth-like exoplanets and gather important scientific information about them.