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Solar System: Things to Know This Week

Mark your calendars for summer 2018: That's when we're launching a spacecraft to touch the sun. 

In honor of our first-ever mission to the heart of the solar system, this week we’re delving into the life and times of this powerful yellow dwarf star.

1. Meet Parker 

Parker Solar Probe, our first mission to go to the sun, is named after Eugene Parker, an American astrophysicist who first theorized that the sun constantly sends out a flow of particles and energy called the solar wind. This historic mission will explore one of the last regions of the solar system to be visited by a spacecraft and help scientists unlock answers to questions they've been pondering for more than five decades.

2. Extra SPF, Please 

Parker Solar Probe will swoop within 4 million miles of the sun's surface, facing heat and radiation like no spacecraft before it. The mission will provide new data on solar activity to help us better understand our home star and its activity - information that can improve forecasts of major space-weather events that could impact life on Earth.

3. Majorly Massive 

The sun is the center of our solar system and makes up 99.8 percent of the mass of the entire solar system. If the sun were as tall as a typical front door, Earth would be about the size of a nickel.

4. Different Spin 

Since the sun is not a solid body, different parts of the sun rotate at different rates. At the equator, the sun spins once about every 25 days, but at its poles the sun rotates once on its axis every 36 Earth days.

5. Can't Stand on It

The sun is a star and a star doesn't have a solid surface. Rather, it's a ball of ionized gas 92.1% hydrogen (H2) and 7.8% helium (He) held together by its own gravity.

6. Center of Attention 

The sun isn't a planet, so it doesn't have any moons. But, the sun is orbited by eight planets, at least five dwarf planets, tens of thousands of asteroids, and hundreds of thousands to trillions of comets and icy bodies.

7. It's Hot in There 

And we mean really, really hot. The temperature at the sun's core is about 27 million degrees Fahrenheit. However, its atmosphere, the corona, can reach temperatures of 3 million degrees. (That's as if it got hotter the farther away you got from a fire, instead of cooler!) Parker Solar Probe will help scientists solve the mystery of why the corona's temperature is so much higher than the surface.

8. Travel Conditions

The sun influences the entire solar system, so studying it helps us better understand the space weather that our astronauts and spacecraft travel through.

9. Life on the Sun? 

Better to admire from afar. Thanks to its hot, energetic mix of gases and plasma, the sun can't be home to living things. However, we can thank the sun for making life on Earth possible by providing the warmth and energy that supply Earth’s food chain.

10. Chance of a Lifetime 

Last but not least, don't forget that the first total solar eclipse to sweep across the U.S. from coast-to-coast since 1918 is happening on August 21, 2017. Our toolkit has you need to know to about it. 

Want to learn more? Read our full list of the 10 things to know this week about the solar system HERE.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Wispy remains of a supernova explosion hide a possible 'survivor.' Of all the varieties of exploding stars, the ones called Type Ia are perhaps the most intriguing. Their predictable brightness lets astronomers measure the expansion of the universe, which led to the discovery of dark energy. Yet the cause of these supernovae remains a mystery. Do they happen when two white dwarf stars collide? Or does a single white dwarf gorge on gases stolen from a companion star until bursting? If the second theory is true, the normal star should survive. Astronomers used the Hubble Space Telescope to search the gauzy remains of a Type Ia supernova in a neighboring galaxy called the Large Magellanic Cloud. They found a sun-like star that showed signs of being associated with the supernova. Further investigations will be needed to learn if this star is truly the culprit behind a white dwarf's fiery demise.

 This supernova remnant is located 160,000 light-years from Earth. The actual supernova remnant is the irregular shaped dust cloud, at the upper center of the image. The gas in the lower half of the image and the dense concentration of stars in the lower left are the outskirts of a star cluster.

Image credit: NASA, ESA and H.-Y. Chu (Academia Sinica, Taipei)

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

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

It’s Friday...Come Space Out with Us

It’s Friday…which seems like a great excuse to take a look at some awesome images from space.

First, let’s start with our home planet: Earth.

This view of the entire sunlit side of Earth was taken from one million miles away…yes, one MILLION! Our EPIC camera on the Deep Space Climate Observatory captured this image in July 2015 and the picture was generated by combining three separate images to create a photographic-quality image.

Next, let’s venture out 4,000 light-years from Earth.

This image, taken by the Hubble Space Telescope, is not only stunning…but shows the colorful “last hurrah” of a star like our sun. This star is ending its life by casting off its outer layers of gas, which formed a cocoon around the star’s remaining core. Our sun will eventually burn out and shroud itself with stellar debris…but not for another 5 billion years.

The material expelled by the star glows with different colors depending on its composition, its density and how close it is to the hot central star. Blue samples helium; blue-green oxygen, and red nitrogen and hydrogen.

Want to see some rocks on Mars?

Here’s an image of the layered geologic past of Mars revealed in stunning detail. This color image was returned by our Curiosity Mars rover, which is currently “roving” around the Red Planet, exploring the “Murray Buttes” region.

In this region, Curiosity is investigating how and when the habitable ancient conditions known from the mission’s earlier findings evolved into conditions drier and less favorable for life.

Did you know there are people currently living and working in space?

Right now, three people from three different countries are living and working 250 miles above Earth on the International Space Station. While there, they are performing important experiments that will help us back here on Earth, and with future exploration to deep space.

This image, taken by NASA astronaut Kate Rubins shows the stunning moonrise over Earth from the perspective of the space station.

Lastly, let’s venture over to someplace REALLY hot…our sun.

The sun is the center of our solar system, and makes up 99.8% of the mass of the entire solar system…so it’s pretty huge. Since the sun is a star, it does not have a solid surface, but is a ball of gas held together by its own gravity. The temperature at the sun’s core is about 27 million degrees Fahrenheit (15 million degrees Celsius)…so HOT!

This awesome visualization appears to show the sun spinning, as if stuck on a pinwheel. It is actually the spacecraft, SDO, that did the spinning though. Engineers instructed our Solar Dynamics Observatory (SDO) to roll 360 degrees on one axis, during this seven-hour maneuver, the spacecraft took an image every 12 seconds.

This maneuver happens twice a year to help SDO’s imager instrument to take precise measurements of the solar limb (the outer edge of the sun as seen by SDO).

Thanks for spacing out with us...you may now resume your Friday. 

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

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. 

More Info

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.

More info

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.

More info

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.

More info

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.

More info

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.

More info

7. Kepler-22b

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

More info

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.

More info

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.

More info

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. 

More info

What’s Up for October?

This month is filled with exciting celestial sights. Here are 10 targets you can view this month:

10. Unusual Sunset

During a sunset, our thick atmosphere absorbs most colors of sunlight, but red light is absorbed the least. Rarely, green flashes can be seen just above the sun’s edge. As the last sliver of the disk disappears below the horizon, be sure to watch its color.

9. Belt of Venus

Just after sunset, turn around and face east. A dark shadow will move up from the horizon and gradually cover the pinkish sky. This is caused from the Earth itself blocking the sunlight and is called the Earth Shadow or the Belt of Venus.

8. Crepuscular Rays

Also just after sunset, or before dawn, you may see rays of sunlight spread like a fan. These are called crepuscular rays and are formed when sunlight streams through gaps in the clouds or mountains.

7. Aurora Borealis

The northern lights, also known as the aurora borealis, are caused by collisions between gaseous particles in Earth’s atmosphere and charged particles released from the sun. The color of the lights can changed depending on the type of gas being struck by particles of solar wind. You can find out when and where to expect aurorae at the Space Weather Prediction Center.

6. Andromeda Galaxy

Did you now that The Andromeda Galaxy is one of the few you can actually see with your naked eye? In October, look nearly overhead after sunset to see it! This galaxy is more than twice the apparent width of the moon.

5. Moon Features

Nights in mid-October are excellent for viewing the features on the moon. Areas like the Sea of Tranquility and the site of the 1969 Apollo 11 landing will be visible.

4. A Comet

This month, the European Space Agency’s Rosetta mission target, a comet with a complicated name (Comet 67P Churyumov-Gerasimenko), is still bright enough for experienced astronomers to pick out in a dark sky. On October 9, you may be able to spot it in the east near the crescent moon and Venus.

3. Meteor Showers

There are multiple meteor showers this month. On the 9th: watch the faint, slow-moving Draconids. On the 10th: catch the slow, super-bright Taurids. And on the 21st: don’t’ miss the swift and bright Orionids from the dust of Comet Halley.

2. Three Close Planets

On October 28, you’ll find a tight grouping of Jupiter, Venus and Mars in the eastern sky before sunrise.

1. Zodiacal Light

The Zodiacal light is a faint triangular glow that can be seen from a dark sky after sunset or before sunrise. What you’re seeing is sunlight reflecting off dust grains that circle the sun in the inner solar system. These dust grains travel in the same plane as the moon and planets as they journey across our sky.

For more stargazing tools visit: Star Tool Box

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com