Galaxies - Blog Posts

O_o  When we peer deep into space, we don't expect to find something staring back at us...

This galactic ghoul, captured by our Hubble Space Telescope, is actually a titanic head-on collision between two galaxies. Each "eye" is the bright core of a galaxy, one of which slammed into another. The outline of the face is a ring of young blue stars. Other clumps of new stars form a nose and mouth.

Although galaxy collisions are common most of them are not head-on smashups like this Arp-Madore system. Get spooked & find out what lies inside this ghostly apparition, here. 

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The Science Goals of the James Webb Space Telescope

Our James Webb Space Telescope is an epic mission that will give us a window into the early universe, allowing us to see the time period during which the first stars and galaxies formed. Webb will not only change what we know, but also how we think about the night sky and our place in the cosmos. Want to learn more? Join two of our scientists as they talk about what the James Webb Telescope is, why it is being built and what it will help us learn about the universe…

First, meet Dr. Amber Straughn. She grew up in a small farming town in Arkansas, where her fascination with astronomy began under beautifully dark, rural skies. After finishing a PhD in Physics, she came to NASA Goddard to study galaxies using data from our Hubble Space Telescope. In addition to research, Amber's role with the Webb project’s science team involves working with Communications and Outreach activities. She is looking forward to using data from Webb in her research on galaxy formation and evolution.

We also talked with Dr. John Mather, the Senior Project Scientist for Webb, who leads our science team. He won a Nobel Prize in 2006 for confirming the Big Bang theory with extreme precision via a mission called the Cosmic Background Explorer (COBE) mission. John was the Principal Investigator (PI) of the Far IR Absolute Spectrophotometer (FIRAS) instrument on COBE.  He’s an expert on cosmology, and infrared astronomy and instrumentation. 

Now, let’s get to the science of Webb!

Dr. Amber Straughn: The James Webb Space Telescope at its core is designed to answer some of the biggest questions we have in astronomy today. And these are questions that go beyond just being science questions; they are questions that really get to the heart of who we are as human beings; questions like where do we come from? How did we get here? And, of course, the big one – are we alone?

To answer the biggest questions in astronomy today we really need a very big telescope. And the James Webb Space Telescope is the biggest telescope we’ve ever attempted to send into space. It sets us up with some really big engineering challenges.

Dr. John Mather: One of the wonderful challenges about astronomy is that we have to imagine something so we can go look for it. But nature has a way of being even more creative than we are, so we have always been surprised by what we see in the sky. That’s why building a telescope has always been interesting. Every time we build a better one, we see something we never imagined was out there. That’s been going on for centuries. This is the next step in that great series, of bigger and better and more powerful telescopes that surely will surprise us in some way that I can’t tell you.

It has never been done before, building a big telescope that will unfold in space. We knew we needed something that was bigger than the rocket to achieve the scientific discoveries that we wanted to make. We had to invent a new way to make the mirrors, a way to focus it out in outer space, several new kinds of infrared detectors, and we had to invent the big unfolding umbrella we call the sunshield.

Amber: One of Webb’s goals is to detect the very first stars and galaxies that were born in the very early universe. This is a part of the universe that we haven’t seen at all yet. We don’t know what’s there, so the telescope in a sense is going to open up this brand-new part of the universe, the part of the universe that got everything started.

John: The first stars and galaxies are really the big mystery for us. We don’t know how that happened. We don’t know when it happened. We don’t know what those stars were like. We have a pretty good idea that they were very much larger than the sun and that they would burn out in a tremendous burst of glory in just a few million years.

Amber: We also want to watch how galaxies grow and change over time. We have questions like how galaxies merge, how black holes form and how gas inflows and outflows affect galaxy evolution. But we’re really missing a key piece of the puzzle, which is how galaxies got their start.

John: Astronomy is one of the most observationally based sciences we’ve ever had. Everything we know about the sky has been a surprise. The ancients knew about the stars, but they didn’t know they were far away. They didn’t know they were like the Sun. Eventually we found that our own galaxy is one of hundreds of billions of galaxies and that the Universe is actually very old, but not infinitely old. So that was a big surprise too. Einstein thought, of course the Universe must have an infinite age, without a starting point. Well, he was wrong! Our intuition has just been wrong almost all the time. We’re pretty confident that we don’t know what we’re going to find.

Amber: As an astronomer one of the most exciting things about working on a telescope like this is the prospect of what it will tell us that we haven’t even thought of yet. We have all these really detailed science questions that we’ll ask, that we know to ask, and that we’ll answer. And in a sense that is what science is all about… in answering the questions we come up with more questions. There’s this almost infinite supply of questions, of things that we have to learn. So that’s why we build telescopes to get to this fundamental part of who we are as human beings. We’re explorers, and we want to learn about what our Universe is like. 

Webb will be the world's premier space science observatory. It will solve mysteries in our solar system, look beyond to distant worlds around other stars and probe the mysterious structures and origins of our universe – including our place in it. Webb is an international project we’re leading with our partners, ESA (European Space Agency) and the Canadian Space Agency.

To learn more about our James Webb Space Telescope, visit the website, or follow the mission on Facebook, Twitter and Instagram.

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What would happen if I go into a black hole? Do you think I would disappear forever or would I still exist inside the black hole?

Hubble’s 5 Weirdest Black Hole Discoveries

Our Hubble Space Telescope has been exploring the wonders of the universe for nearly 30 years, answering some of our deepest cosmic questions. Some of Hubble’s most exciting observations have been about black holes — places in space where gravity pulls so much that not even light can escape. As if black holes weren’t wild enough already, Hubble has helped us make discoveries that show us they’re even weirder than we thought!

Supermassive Black Holes Are Everywhere

First, these things are all over the place. If you look at any random galaxy in the universe, chances are it has a giant black hole lurking in its heart. And when we say giant, we’re talking as massive as millions or even billions of stars! 

Hubble found that the mass of these black holes, hidden away in galactic cores, is linked to the mass of the host galaxy — the bigger the galaxy, the bigger the black hole. Scientists think this may mean that the black holes grew along with their galaxies, eating up some of the stuff nearby.

Some Star Clusters Have Black Holes

A globular cluster is a ball of old, very similar stars that are bound together by gravity. They’re fairly common — our galaxy has at least 150 of them — but Hubble has found some black sheep in the herd. Some of these clusters are way more massive than usual, have a wide variety of stars and may even harbor a black hole at the center. This suggests that at least some of the globular clusters in our galaxy may have once been dwarf galaxies that we absorbed.

Black Hole Jets Regulate Star Birth

While black holes themselves are invisible, sometimes they shoot out huge jets of energy as gas and dust fall into them. Since stars form from gas and dust, the jets affect star birth within the galaxy. 

Sometimes they get rid of the fuel needed to keep making new stars, but Hubble saw that it can also keep star formation going at a slow and steady rate.

Black Holes Growing in Colliding Galaxies

If you’ve ever spent some time stargazing, you know that staring up into a seemingly peaceful sea of stars can be very calming. But the truth is, it’s a hectic place out there in the cosmos! Entire galaxies — these colossal collections of gas, dust, and billions of stars with their planets — can merge together to form one supergalaxy. You might remember that most galaxies have a supermassive black hole at the center, so what happens to them when galaxies collide? 

In 2018, Hubble unveiled the best view yet of close pairs of giant black holes in the act of merging together to form mega black holes!

Gravitational Wave Kicks Monster Black Hole Out of Galactic Core

What better way to spice up black holes than by throwing gravitational waves into the mix! Gravitational waves are ripples in space-time that can be created when two massive objects orbit each other. 

In 2017, Hubble found a rogue black hole that is flying away from the center of its galaxy at over 1,300 miles per second (about 90 times faster than our Sun is traveling through the Milky Way). What booted the black hole out of the galaxy’s core? Gravitational waves! Scientists think that this is a case where two galaxies are in the late stages of merging together, which means their central black holes are probably merging too in a super chaotic process. 

Want to learn about more of the highlights of Hubble’s exploration? Check out this page! https://www.nasa.gov/content/goddard/2017/highlights-of-hubble-s-exploration-of-the-universe

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How Do You Solve a Problem Like Dark Energy?

Here’s the deal — the universe is expanding. Not only that, but it’s expanding faster and faster due to the presence of a mysterious substance scientists have named “dark energy.”

But before we get to dark energy, let’s first talk a bit about the expanding cosmos. It started with the big bang — when the universe started expanding from a hot, dense state about 13.8 billion years ago. Our universe has been getting bigger and bigger ever since. Nearly every galaxy we look at is zipping away from us, caught up in that expansion!

The expansion, though, is even weirder than you might imagine. Things aren’t actually moving away from each other. Instead, the space between them is getting larger.

Imagine that you and a friend were standing next to each other. Just standing there, but the floor between you was growing. You two aren’t technically moving, but you see each other moving away. That’s what’s happening with the galaxies (and everything else) in our cosmos ... in ALL directions!

Astronomers expected the expansion to slow down over time. Why? In a word: gravity. Anything that has mass or energy has gravity, and gravity tries to pull stuff together. Plus, it works over the longest distances. Even you, reading this, exert a gravitational tug on the farthest galaxy in the universe! It’s a tiny tug, but a tug nonetheless.

As the space between galaxies grows, gravity is trying to tug the galaxies back together — which should slow down the expansion. So, if we measure the distance of faraway galaxies over time, we should be able to detect if the universe's growth rate slows down.  

But in 1998, a group of astronomers measured the distance and velocity of a number of galaxies using bright, exploding stars as their “yardstick.” They found out that the expansion was getting faster.

Not slowing down.

Speeding up.

⬆️ This graphic illustrates the history of our expanding universe. We do see some slowing down of the expansion (the uphill part of the graph, where the roller coaster is slowing down). However, at some point, dark energy overtakes gravity and the expansion speeds up (the downhill on the graph). It’s like our universe is on a giant roller coaster ride, but we’re not sure how steep the hill is!

Other researchers also started looking for signs of accelerated expansion. And they found it — everywhere. They saw it when they looked at individual stars. They saw it in large scale structures of the universe, like galaxies, galaxy groups and clusters. They even saw it when they looked at the cosmic microwave background (that’s what’s in this image), a "baby picture" of the universe from just a few hundred thousand years after the big bang.

If you thought the roller coaster was wild, hold on because things are about to get really weird.

Clearly, we were missing something. Gravity wasn’t the biggest influence on matter and energy across the largest scales of the universe. Something else was. The name we’ve given to that “something else” is dark energy.

We don’t know exactly what dark energy is, and we’ve never detected it directly. But we do know there is a lot of it. A lot. If you summed up all the “stuff” in the universe — normal matter (the stuff we can touch or observe directly), dark matter, and dark energy — dark energy would make up more than two-thirds of what is out there.

That’s a lot of our universe to have escaped detection!

Researchers have come up with a few dark energy possibilities. Einstein discarded an idea from his theory of general relativity about an intrinsic property of space itself. It could be that this bit of theory got dark energy right after all. Perhaps instead there is some strange kind of energy-fluid that fills space. It could even be that we need to tweak Einstein’s theory of gravity to work at the largest scales.  

We’ll have to stay tuned as researchers work this out.

Our Wide Field Infrared Survey Telescope (WFIRST) — planned to launch in the mid-2020s — will be helping with the task of unraveling the mystery of dark energy. WFIRST will map the structure and distribution of matter throughout the cosmos and across cosmic time. It will also map the universe’s expansion and study galaxies from when the universe was a wee 2-billion-year-old up to today. Using these new data, researchers will learn more than we’ve ever known about dark energy. Perhaps even cracking open the case!

You can find out more about the history of dark energy and how a number of different pieces of observational evidence led to its discovery in our Cosmic Times series. And keep an eye on WFIRST to see how this mystery unfolds.

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Look! A cosmic block party 🥳 In this Hubble image, you’ll find 50 spiral and dwarf galaxies hanging out in our cosmic neighborhood. The main focal point of stars is actually a dwarf galaxy. Dwarf galaxies often show a hazy structure, an ill-defined shape and an appearance somewhat akin to a swarm or cloud of stars — and UGC 685 is no exception to this. These data were gathered under Hubble’s Legacy ExtraGalactic UV Survey (LEGUS) program, the sharpest and most comprehensive ultraviolet survey of star-forming galaxies in the nearby universe. Image Credit: ESA/Hubble & NASA; the LEGUS team, B. Tully, D. Calzetti

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Say hello to the Butterfly Nebula 👋

It looks like our Hubble Space Telescope captured an image of a peaceful, cosmic butterfly unfurling its celestial wings, but the truth is vastly more violent. In the Butterfly Nebula, layers of gas are being ejected from a dying star. Medium-mass stars grow unstable as they run out of fuel, which leads them to blast tons of material out into space at speeds of over a million miles per hour!

Streams of intense ultraviolet radiation cause the cast-off material to glow, but eventually the nebula will fade and leave behind only a small stellar corpse called a white dwarf. Our middle-aged Sun can expect a similar fate once it runs out of fuel in about six billion years.

Planetary nebulas like this one aren’t actually related to planets; the term was coined by astronomer William Herschel, who actually discovered the Butterfly Nebula in 1826. Through his small telescope, planetary nebulas looked like glowing, planet-like orbs. While stars that generate planetary nebulas may have once had planets orbiting them, scientists expect that the fiery death throes these stars undergo will ultimately leave any planets in their vicinity completely uninhabitable.

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That star stuff you see here? That's what you're made of. You possess the elements ✨ ⁣

This composite image from our Chandra X-ray Observatory, the Spitzer Space Telescope and the Isaac Newton Telescope shows high-energy X-rays emitted by young, massive stars in the star cluster Cygnus OB2. This year we're celebrating the 20th anniversary of Chandra's launch. Want to dive deeper? Click here

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How Gravity Warps Light

Gravity is obviously pretty important. It holds your feet down to Earth so you don’t fly away into space, and (equally important) it keeps your ice cream from floating right out of your cone! We’ve learned a lot about gravity over the past few hundred years, but one of the strangest things we’ve discovered is that most of the gravity in the universe comes from an invisible source called “dark matter.” While our telescopes can’t directly see dark matter, they can help us figure out more about it thanks to a phenomenon called gravitational lensing.

The Gravity of the Situation

Anything that has mass is called matter, and all matter has gravity. Gravity pulls on everything that has mass and warps space-time, the underlying fabric of the universe. Things like llamas and doughnuts and even paper clips all warp space-time, but only a tiny bit since they aren’t very massive.

But huge clusters of galaxies are so massive that their gravity produces some pretty bizarre effects. Light always travels in a straight line, but sometimes its path is bent. When light passes close to a massive object, space-time is so warped that it curves the path the light must follow. Light that would normally be blocked by the galaxy cluster is bent around it, producing intensified — and sometimes multiple — images of the source. This process, called gravitational lensing, turns galaxy clusters into gigantic, intergalactic magnifying glasses that give us a glimpse of cosmic objects that would normally be too distant and faint for even our biggest telescopes to see.

Hubble “Sees” Dark Matter

Let’s recap — matter warps space-time. The more matter, the stronger the warp and the bigger its gravitational lensing effects. In fact, by studying “lensed” objects, we can map out the quantity and location of the unseen matter causing the distortion!

Thanks to gravitational lensing, scientists have measured the total mass of many galaxy clusters, which revealed that all the matter they can see isn’t enough to create the warping effects they observe. There’s more gravitational pull than there is visible stuff to do the pulling — a lot more! Scientists think dark matter accounts for this difference. It’s invisible to our eyes and telescopes, but it can’t hide its gravity!

The mismatch between what we see and what we know must be there may seem strange, but it’s not hard to imagine. You know that people can’t float in mid-air, so what if you saw a person appearing to do just that? You would know right away that there must be wires holding him up, even if you couldn’t see them.

Our Hubble Space Telescope observations are helping unravel the dark matter mystery. By studying gravitationally lensed galaxy clusters with Hubble, astronomers have figured out how much of the matter in the universe is “normal” and how much is “dark.” Even though normal matter makes up everything from pickles to planets, there’s about five times more dark matter in the universe than all the normal matter combined!

WFIRST Will Escalate the Search

One of our next major space telescopes, the Wide Field Infrared Survey Telescope (WFIRST), will take these gravitational lensing observations to the next level. WFIRST will be sensitive enough to use weak gravitational lensing to see how clumps of dark matter warp the appearance of distant galaxies. By observing lensing effects on this small scale, scientists will be able to fill in more of the gaps in our understanding of dark matter.

WFIRST will observe a sky area 100 times larger than Hubble does, but with the same awesome image quality. WFIRST will collect so much data in its first year that it will allow scientists to conduct in-depth studies that would have taken hundreds of years with previous telescopes.

WFIRST’s weak gravitational lensing observations will allow us to peer even further back in time than Hubble is capable of seeing. Scientists believe that the universe’s underlying dark matter structure played a major role in the formation and evolution of galaxies by attracting normal matter. Seeing the universe in its early stages will help scientists unravel how it has evolved over time and possibly provide clues to how it may continue to evolve. We don’t know what the future will hold, but WFIRST will help us find out.

This science is pretty mind-bending, even for scientists. Learn more as our current and future telescopes plan to help unlock these mysteries of the universe...

Hubble: https://www.nasa.gov/mission_pages/hubble/main/index.html WFIRST: https://wfirst.gsfc.nasa.gov/

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How Do Space Telescopes Break Down Light?

Space telescopes like Hubble and our upcoming James Webb Space Telescope use light not only to create images, but can also break light down into individual colors (or wavelengths). Studying light this way can give us a lot of detail about the object that emitted that light.  For example, studying the components of the light from exoplanets can tell us about its atmosphere’s color, chemical makeup, and temperature. How does this work?

Remember the primary colors you learned about in elementary school?

Those colors are known as the pigment or subtractive colors. Every other color is some combination of the primary colors: red, yellow, and blue.

Light also has its own primary colors, and they work in a similar way. These colors are known as additive or light colors.          

TVs make use of light’s colors to create the pictures we see. Each pixel of a TV screen contains some amount of red, green and blue light. The amount of each light determines the overall color of the pixel. So, each color on the TV comes from a combination of the primary colors of light: red, green and blue.

Space telescope images of celestial objects are also a combination of the colors of light.

Every pixel that is collected can be broken down into its base colors. To learn even more, astronomers break the red, green and blue light down into even smaller sections called wavelengths.

This breakdown is called a spectrum.

With the right technology, every pixel of light can also be measured as a spectrum.

Images show us the big picture, while a spectrum reveals finer details.  Astronomers use spectra to learn things like what molecules are in planet atmospheres and distant galaxies.

An Integral Field Unit, or IFU, is a special tool on the James Webb Space Telescope that captures images and spectra at the same time.

The IFU creates a unique spectrum for each pixel of the image the telescope is capturing, providing scientists with an enormous amount of valuable, detailed data. So, with an IFU we can get an image, many spectra and a better understanding of our universe.

Watch the full video where this method of learning about planetary atmospheres is explained:

The James Webb Space Telescope is our upcoming infrared space observatory, which will launch in 2021. It will spy the first galaxies that formed in the universe and shed light on how galaxies evolve, how stars and planetary systems are born and tell us about potentially habitable planets around other stars.

To learn more about NASA’s James Webb Space Telescope, visit the website, or follow the mission on Facebook, Twitter and Instagram.

Text and graphics credit: Space Telescope Science Institute

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How Big is Our Galaxy, the Milky Way?

When we talk about the enormity of the cosmos, it’s easy to toss out big numbers – but far harder to wrap our minds around just how large, how far and how numerous celestial bodies like exoplanets – planets beyond our solar system – really are.

So. How big is our Milky Way Galaxy?

We use light-time to measure the vast distances of space.

It’s the distance that light travels in a specific period of time. Also: LIGHT IS FAST, nothing travels faster than light.

How far can light travel in one second? 186,000 miles. It might look even faster in metric: 300,000 kilometers in one second. See? FAST.

How far can light travel in one minute? 11,160,000 miles. We’re moving now! Light could go around the Earth a bit more than 448 times in one minute.

Speaking of Earth, how long does it take light from the Sun to reach our planet? 8.3 minutes. (It takes 43.2 minutes for sunlight to reach Jupiter, about 484 million miles away.) Light is fast, but the distances are VAST.

In an hour, light can travel 671 million miles. We’re still light-years from the nearest exoplanet, by the way. Proxima Centauri b is 4.2 light-years away. So… how far is a light-year? 5.8 TRILLION MILES.

A trip at light speed to the very edge of our solar system – the farthest reaches of the Oort Cloud, a collection of dormant comets way, WAY out there – would take about 1.87 years.

Our galaxy contains 100 to 400 billion stars and is about 100,000 light-years across!

One of the most distant exoplanets known to us in the Milky Way is Kepler-443b. Traveling at light speed, it would take 3,000 years to get there. Or 28 billion years, going 60 mph. So, you know, far.

SPACE IS BIG.

Read more here: go.nasa.gov/2FTyhgH

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The James Webb Space Telescope: Art + Science Continuing to Inspire

The James Webb Space Telescope – our next infrared space observatory – will not only change what we know, but also how we think about the night sky and our place in the cosmos. This epic mission to travel back in time to look back at the first stars and galaxies has inspired artists from around the world to create art inspired by the mission.

Image Credit: Anri Demchenko

It’s been exactly two years since the opening of the first James Webb Space Telescope Art + Science exhibit at the NASA Goddard Visitor Center.  The exhibit was full of pieces created by artists who had the special opportunity to visit Goddard and view the telescope in person in late 2016. 

Online Submission Image Credit: Tina Saramaga

Since the success of the event and exhibit, the Webb project has asked its followers to share any art they have created that was inspired by the mission. They have received over 125 submissions and counting!  

Image Credit: Enrico Novelli

Online Submission Image Credit: Unni Isaksen

A selection of these submissions will be on display at NASA Goddard’s Visitor Center from now until at least the end of April 2019. The artists represented in this exhibit come not just from around the country, but from around the world, showing how art and science together can bring a love of space down to Earth.

More information about each piece in the exhibit can be found in our web gallery. Want to participate and share your own art? Tag your original art, inspired by the James Webb Space Telescope, on Twitter or Instagram with #JWSTArt, or email us through our website! For more info and rules, see: http://nasa.gov/jwstart.

Webb is the work of hands and minds from across the planet. We’re leading this international project with our partners from the European Space Agency (ESA) and the Canadian Space Agency (CSA), and we’re all looking forward to its launch in 2021. Once in space, Webb will solve mysteries of our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it.

Learn more about the James Webb Space Telescope HERE, or follow the mission on Facebook, Twitter and Instagram.

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Dark Matter 101: Looking for the missing mass

Here’s the deal — here at NASA we share all kinds of amazing images of planets, stars, galaxies, astronauts, other humans, and such, but those photos can only capture part of what’s out there. Every image only shows ordinary matter (scientists sometimes call it baryonic matter), which is stuff made from protons, neutrons and electrons. The problem astronomers have is that most of the matter in the universe is not ordinary matter – it’s a mysterious substance called dark matter.  

What is dark matter? We don’t really know. That’s not to say we don’t know anything about it – we can see its effects on ordinary matter. We’ve been getting clues about what it is and what it is not for decades. However, it’s hard to pinpoint its exact nature when it doesn’t emit light our telescopes can see. 

Misbehaving galaxies

The first hint that we might be missing something came in the 1930s when astronomers noticed that the visible matter in some clusters of galaxies wasn’t enough to hold the cluster together. The galaxies were moving so fast that they should have gone zinging out of the cluster before too long (astronomically speaking), leaving no cluster behind.

Simulation credit: ESO/L. Calçada

It turns out, there’s a similar problem with individual galaxies. In the 1960s and 70s, astronomers mapped out how fast the stars in a galaxy were moving relative to its center. The outer parts of every single spiral galaxy the scientists looked at were traveling so fast that they should have been flying apart.

Something was missing – a lot of it! In order to explain how galaxies moved in clusters and stars moved in individual galaxies, they needed more matter than scientists could see. And not just a little more matter. A lot . . . a lot, a lot. Astronomers call this missing mass “dark matter” — “dark” because we don’t know what it is. There would need to be five times as much dark matter as ordinary matter to solve the problem.  

Holding things together

Dark matter keeps galaxies and galaxy clusters from coming apart at the seams, which means dark matter experiences gravity the same way we do.

In addition to holding things together, it distorts space like any other mass. Sometimes we see distant galaxies whose light has been bent around massive objects on its way to us. This makes the galaxies appear stretched out or contorted. These distortions provide another measurement of dark matter.

Undiscovered particles?

There have been a number of theories over the past several decades about what dark matter could be; for example, could dark matter be black holes and neutron stars – dead stars that aren’t shining anymore? However, most of the theories have been disproven. Currently, a leading class of candidates involves an as-yet-undiscovered type of elementary particle called WIMPs, or Weakly Interacting Massive Particles.

Theorists have envisioned a range of WIMP types and what happens when they collide with each other. Two possibilities are that the WIMPS could mutually annihilate, or they could produce an intermediate, quickly decaying particle. In both cases, the collision would end with the production of gamma rays — the most energetic form of light — within the detection range of our Fermi Gamma-ray Space Telescope.

Tantalizing evidence close to home

A few years ago, researchers took a look at Fermi data from near the center of our galaxy and subtracted out the gamma rays produced by known sources. There was a left-over gamma-ray signal, which could be consistent with some forms of dark matter.

While it was an exciting finding, the case is not yet closed because lots of things at the center of the galaxy make gamma rays. It’s going to take multiple sightings using other experiments and looking at other astronomical objects to know for sure if this excess is from dark matter.

In the meantime, Fermi will continue the search, as it has over its 10 years in space. Learn more about Fermi and how we’ve been celebrating its first decade in space.

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Things That Go Bump in the Gamma Rays

Some people watch scary movies because they like being startled. A bad guy jumps out from around a corner! A monster emerges from the shadows! Scientists experience surprises all the time, but they’re usually more excited than scared. Sometimes theories foreshadow new findings — like when there’s a dramatic swell in the movie soundtrack — but often, discoveries are truly unexpected. 

Scientists working with the Fermi Gamma-Ray Space Telescope have been jumping to study mysterious bumps in the gamma rays for a decade now. Gamma rays are the highest-energy form of light. Invisible to human eyes, they’re created by some of the most powerful and unusual events and objects in the universe. In celebration of Halloween, here are a few creepy gamma-ray findings from Fermi’s catalog.

Stellar Graveyards

If you were to walk through a cemetery at night, you’d expect to trip over headstones or grave markers. Maybe you’d worry about running into a ghost. If you could explore the stellar gravesite created when a star explodes as a supernova, you’d find a cloud of debris expanding into interstellar space. Some of the chemical elements in that debris, like gold and platinum, go on to create new stars and planets! Fermi found that supernova remnants IC 443 and W44 also accelerate mysterious cosmic rays, high-energy particles moving at nearly the speed of light. As the shockwave of the supernova expands, particles escape its magnetic field and interact with non-cosmic-ray particles to produce gamma rays. 

Ghost Particles

But the sources of cosmic rays aren’t the only particle mysteries Fermi studies. Just this July, Fermi teamed up with the IceCube Neutrino Observatory in Antarctica to discover the first source of neutrinos outside our galactic neighborhood. Neutrinos are particles that weigh almost nothing and rarely interact with anything. Around a trillion of them pass through you every second, ghost-like, without you noticing and then continue on their way. (But don’t worry, like a friendly ghost, they don’t harm you!) Fermi traced the neutrino IceCube detected back to a supermassive black hole in a distant galaxy. By the time it reached Earth, it had traveled for 3.7 billion years at almost the speed of light!

Black Widow Pulsars

Black widows and redbacks are species of spiders with a reputation for devouring their partners. Astronomers have discovered two types of star systems that behave in a similar way. Sometimes when a star explodes as a supernova, it collapses back into a rapidly spinning, incredibly dense star called a pulsar. If there’s a lighter star nearby, it can get stuck in a close orbit with the pulsar, which blasts it with gamma rays, magnetic fields and intense winds of energetic particles. All these combine to blow clouds of material off the low-mass star. Eventually, the pulsar can eat away at its companion entirely.

Dark Matter

What’s scarier than a good unsolved mystery? Dark matter is a little-understood substance that makes up most of the matter in the universe. The stuff that we can see — stars, people, haunted houses, candy — is made up of normal matter. But our surveys of the cosmos tell us there’s not enough normal matter to keep things working the way they do. There must be another type of matter out there holding everything together. One of Fermi’s jobs is to help scientists narrow down the search for dark matter. Last year, researchers noticed that most of the gamma rays coming from the Andromeda galaxy are confined to its center instead of being spread throughout. One possible explanation is that accumulated dark matter at the center of the galaxy is emitting gamma rays!

Fermi has helped us learn a lot about the gamma-ray universe over the last 10 years. Learn more about its accomplishments and the other mysteries it’s working to solve. What other surprises are waiting out among the stars?

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10 Frequently Asked Questions About the James Webb Space Telescope

Got basic questions about the James Webb Space Telescope and what amazing things we’ll learn from it? We’ve got your answers right here! 

The James Webb Space Telescope, or Webb, is our upcoming infrared space observatory, which will launch in 2021. It will spy the first luminous objects that formed in the universe and shed light on how galaxies evolve, how stars and planetary systems are born, and how life could form on other planets.

1. What is the James Webb Space Telescope?

Our James Webb Space Telescope is a giant space telescope that observes infrared light. Rather than a replacement for the Hubble Space Telescope, it’s a scientific successor that will complement and extend its discoveries.

Being able to see longer wavelengths of light than Hubble and having greatly improved sensitivity will let Webb look further back in time to see the first galaxies that formed in the early universe, and to peer inside dust clouds where stars and planetary systems are forming today.

2. What are the most exciting things we will learn?

We have yet to observe the era of our universe’s history when galaxies began to form. 

We have a lot to learn about how galaxies got supermassive black holes in their centers, and we don't really know whether the black holes caused the galaxies to form or vice versa.

We can't see inside dust clouds with high resolution, where stars and planets are being born nearby, but Webb will be able to do just that. 

We don't know how many planetary systems might be hospitable to life, but Webb could tell whether some Earth-like planets have enough water to have oceans.

We don't know much about dark matter or dark energy, but we expect to learn more about where the dark matter is now, and we hope to learn the history of the acceleration of the universe that we attribute to dark energy. 

And then, there are the surprises we can't imagine!

3. Why is Webb an infrared telescope?

By viewing the universe at infrared wavelengths with such sensitivity, Webb will show us things never before seen by any other telescope. For example, it is only at infrared wavelengths that we can see the first stars and galaxies forming after the Big Bang. 

And it is with infrared light that we can see stars and planetary systems forming inside clouds of dust that are opaque to visible light, such as in the above visible and infrared light comparison image of the Carina Nebula.

4. Will Webb take amazing pictures like Hubble? Can Webb see visible light?

YES, Webb will take amazing pictures! We are going to be looking at things we've never seen before and looking at things we have seen before in completely new ways.

The beauty and quality of an astronomical image depends on two things: the sharpness and the number of pixels in the camera. On both of these counts, Webb is very similar to, and in many ways better than, Hubble. 

Additionally Webb can see orange and red visible light. Webb images will be different, but just as beautiful as Hubble's. Above, there is another comparison of infrared and visible light Hubble images, this time of the Monkey Head Nebula.

5. What will Webb's first targets be?

The first targets for Webb will be determined through a process similar to that used for the Hubble Space Telescope and will involve our experts, the European Space Agency (ESA), the Canadian Space Agency (CSA), and scientific community participants.

The first engineering target will come before the first science target and will be used to align the mirror segments and focus the telescope. That will probably be a relatively bright star or possibly a star field.

6. How does Webb compare with Hubble?

Webb is designed to look deeper into space to see the earliest stars and galaxies that formed in the universe and to look deep into nearby dust clouds to study the formation of stars and planets.

In order to do this, Webb has a much larger primary mirror than Hubble (2.5 times larger in diameter, or about 6 times larger in area), giving it more light-gathering power. It also will have infrared instruments with longer wavelength coverage and greatly improved sensitivity than Hubble. 

Finally, Webb will operate much farther from Earth, maintaining its extremely cold operating temperature, stable pointing and higher observing efficiency than with the Earth-orbiting Hubble.

7. What will Webb tell us about planets outside our solar system? Will it take photos of these planets?

Webb will be able to tell us the composition of the atmospheres of planets outside our solar system, aka exoplanets. It will observe planetary atmospheres through the transit technique. A transit is when a planet moves across the disc of its parent star. 

Webb will also carry coronographs to enable photography of exoplanets (planets outside our solar system) near bright stars (if they are big and bright and far from the star), but they will be only "dots," not grand panoramas. Coronographs block the bright light of stars, which could hide nearby objects like exoplanets.

Consider how far away exoplanets are from us, and how small they are by comparison to this distance! We didn’t even know what Pluto really looked like until we were able to send an observatory to fly right near it in 2015, and Pluto is in our own solar system!

8. Will we image objects in our own solar system?

Yes! Webb will be able to observe the planets at or beyond the orbit of Mars, satellites, comets, asteroids and objects in the distant, icy Kuiper Belt.

Many important molecules, ices and minerals have strong characteristic signatures at the wavelengths Webb can observe. 

Webb will also monitor the weather of planets and their moons. 

Because the telescope and instruments have to be kept cold, Webb’s protective sunshield will block the inner solar system from view. This means that the Sun, Earth, Moon, Mercury, and Venus, and of course Sun-grazing comets and many known near-Earth objects cannot be observed.

9. How far back will Webb see? 

Webb will be able to see what the universe looked like around a quarter of a billion years (possibly back to 100 million years) after the Big Bang, when the first stars and galaxies started to form.

10. When will Webb launch and how long is the mission?

Webb will launch in 2021 from French Guiana on a European Space Agency Ariane 5 rocket. 

Webb’s mission lifetime after launch is designed to be at least 5-1/2 years, and could last longer than 10 years. The lifetime is limited by the amount of fuel used for maintaining the orbit, and by the possibility that Webb’s components will degrade over time in the harsh environment of space.

Looking for some more in-depth FAQs? You can find them HERE.

Learn more about the James Webb Space Telescope HERE, or follow the mission on Facebook, Twitter and Instagram.

IMAGE CREDITS Carina Nebula: ESO/T. Preibisch Monkey Head Nebula: NASA, ESA, the Hubble Heritage Team (STScI/AURA), and J. Hester

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When galaxies collide — a common event in the universe — a fresh burst of star formation typically takes place as gas clouds mash together. At this point, the galaxy has a blue hue, but the color does not mean it is cold: it is a result of the intense heat of newly formed blue–white stars. Those stars do not last long, and after a few billion years the reddish hues of aging, smaller stars dominate an elliptical galaxy's spectrum. 

Our Hubble Space Telescope (@NASAHubble) caught sight of a soft, diffuse-looking galaxy, perhaps the aftermath of a long-ago galactic collision when two spiral galaxies, each perhaps much like the Milky Way, swirled together for millions of years.

In such mergers, the original galaxies are often stretched and pulled apart as they wrap around a common center of gravity. After a few back-and-forths, this starry tempest settles down into a new, round object. The now subdued celestial body is technically known as an elliptical galaxy.

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Credit: ESA/Hubble & NASA

The Beauty of Webb Telescope’s Mirrors

The James Webb Space Telescope’s gold-plated, beryllium mirrors are beautiful feats of engineering. From the 18 hexagonal primary mirror segments, to the perfectly circular secondary mirror, and even the slightly trapezoidal tertiary mirror and the intricate fine-steering mirror, each reflector went through a rigorous refinement process before it was ready to mount on the telescope. This flawless formation process was critical for Webb, which will use the mirrors to peer far back in time to capture the light from the first stars and galaxies. 

The James Webb Space Telescope, or Webb, is our upcoming infrared space observatory, which will launch in 2019. It will spy the first luminous objects that formed in the universe and shed light on how galaxies evolve, how stars and planetary systems are born, and how life could form on other planets.  

A polish and shine that would make your car jealous

All of the Webb telescope’s mirrors were polished to accuracies of approximately one millionth of an inch. The beryllium mirrors were polished at room temperature with slight imperfections, so as they change shape ever so slightly while cooling to their operating temperatures in space, they achieve their perfect shape for operations.

The Midas touch

Engineers used a process called vacuum vapor deposition to coat Webb’s mirrors with an ultra-thin layer of gold. Each mirror only required about 3 grams (about 0.11 ounces) of gold. It only took about a golf ball-sized amount of gold to paint the entire main mirror!

Before the deposition process began, engineers had to be absolutely sure the mirror surfaces were free from contaminants. 

The engineers thoroughly wiped down each mirror, then checked it in low light conditions to ensure there was no residue on the surface.

Inside the vacuum deposition chamber, the tiny amount of gold is turned into a vapor and deposited to cover the entire surface of each mirror.

Primary, secondary, and tertiary mirrors, oh my!

Each of Webb’s primary mirror segments is hexagonally shaped. The entire 6.5-meter (21.3-foot) primary mirror is slightly curved (concave), so each approximately 1.3-meter (4.3-foot) piece has a slight curve to it.

Those curves repeat themselves among the segments, so there are only three different shapes — 6 of each type. In the image below, those different shapes are labeled as A, B, and C.

Webb’s perfectly circular secondary mirror captures light from the 18 primary mirror segments and relays those images to the telescope's tertiary mirror.

The secondary mirror is convex, so the reflective surface bulges toward a light source. It looks much like a curved mirror that you see on the wall near the exit of a parking garage that lets motorists see around a corner.

Webb’s trapezoidal tertiary mirror captures light from the secondary mirror and relays it to the fine-steering mirror and science instruments. The tertiary mirror sits at the center of the telescope’s primary mirror. The tertiary mirror is the only fixed mirror in the system — all of the other mirrors align to it.

All of the mirrors working together will provide Webb with the most advanced infrared vision of any space observatory we’ve ever launched!

Who is the fairest of them all?

The beauty of Webb’s primary mirror was apparent as it rotated past a cleanroom observation window at our Goddard Space Flight Center in Greenbelt, Maryland. If you look closely in the reflection, you will see none other than James Webb Space Telescope senior project scientist and Nobel Laureate John Mather!

Learn more about the James Webb Space Telescope HERE, or follow the mission on Facebook, Twitter and Instagram.

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View these celestial beauties taken by the Hubble Space Telescope and released as a set of views in a modern day "Messier Catalog." 

Spotting comets was all the rage in the middle of the 18th century, and at the forefront of the comet hunt was a young French astronomer named Charles Messier. In 1774, in an effort to help fellow comet seekers steer clear of astronomical objects that were not comets (something that frustrated his own search for these elusive entities), Messier published the first version of his “Catalog of Nebulae and Star Clusters,” a collection of celestial objects that weren’t comets and should be avoided during comet hunting. Today, rather than avoiding these objects, many amateur astronomers actively seek them out as interesting targets to observe with backyard telescopes, binoculars or sometimes even with the naked eye.

Hubble’s version of the Messier catalog includes eight newly processed images never before released by NASA. The images were extracted from more than 1.3 million observations that now reside in the Hubble data archive. Some of these images represent the first Hubble views of the objects, while others include newer, higher resolution images taken with Hubble’s latest cameras.

Learn more: https://www.nasa.gov/content/goddard/hubble-s-messier-catalog

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Why Webb Needs to Chill

Our massive James Webb Space Telescope just recently emerged from about 100 days of cryogenic testing to make sure it can work perfectly at incredibly cold temperatures when it’s in deep space. 

How cold did it get and why? Here’s the whole scoop...

Webb is a giant infrared space telescope that we are currently building. It was designed to see things that other telescopes, even the amazing Hubble Space Telescope, can’t see.  

Webb’s giant 6.5-meter diameter primary mirror is part of what gives it superior vision, and it’s coated in gold to optimize it for seeing infrared light.  

Why do we want to see infrared light?

Lots of stuff in space emits infrared light, so being able to observe it gives us another tool for understanding the universe. For example, sometimes dust obscures the light from objects we want to study – but if we can see the heat they are emitting, we can still “see” the objects to study them.

It’s like if you were to stick your arm inside a garbage bag. You might not be able to see your arm with your eyes – but if you had an infrared camera, it could see the heat of your arm right through the cooler plastic bag.

Credit: NASA/IPAC

With a powerful infrared space telescope, we can see stars and planets forming inside clouds of dust and gas.

We can also see the very first stars and galaxies that formed in the early universe. These objects are so far away that…well, we haven’t actually been able to see them yet. Also, their light has been shifted from visible light to infrared because the universe is expanding, and as the distances between the galaxies stretch, the light from them also stretches towards redder wavelengths. 

We call this phenomena “redshift.”  This means that for us, these objects can be quite dim at visible wavelengths, but bright at infrared ones. With a powerful enough infrared telescope, we can see these never-before-seen objects.

We can also study the atmospheres of planets orbiting other stars. Many of the elements and molecules we want to study in planetary atmospheres have characteristic signatures in the infrared.

Because infrared light comes from objects that are warm, in order to detect the super faint heat signals of things that are really, really far away, the telescope itself has to be very cold. How cold does the telescope have to be? Webb’s operating temperature is under 50K (or -370F/-223 C). As a comparison, water freezes at 273K (or 32 F/0 C).

How do we keep the telescope that cold? 

Because there is no atmosphere in space, as long as you can keep something out of the Sun, it will get very cold. So Webb, as a whole, doesn’t need freezers or coolers - instead it has a giant sunshield that keeps it in the shade. (We do have one instrument on Webb that does have a cryocooler because it needs to operate at 7K.)

Also, we have to be careful that no nearby bright things can shine into the telescope – Webb is so sensitive to faint infrared light, that bright light could essentially blind it. The sunshield is able to protect the telescope from the light and heat of the Earth and Moon, as well as the Sun.  

Out at what we call the Second Lagrange point, where the telescope will orbit the Sun in line with the Earth, the sunshield is able to always block the light from bright objects like the Earth, Sun and Moon.

How do we make sure it all works in space? 

By lots of testing on the ground before we launch it. Every piece of the telescope was designed to work at the cold temperatures it will operate at in space and was tested in simulated space conditions. The mirrors were tested at cryogenic temperatures after every phase of their manufacturing process.

The instruments went through multiple cryogenic tests at our Goddard Space Flight Center in Maryland.

Once the telescope (instruments and optics) was assembled, it even underwent a full end-to-end test in our Johnson Space Center’s giant cryogenic chamber, to ensure the whole system will work perfectly in space.  

What’s next for Webb? 

It will move to Northrop Grumman where it will be mated to the sunshield, as well as the spacecraft bus, which provides support functions like electrical power, attitude control, thermal control, communications, data handling and propulsion to the spacecraft.

Learn more about the James Webb Space Telescope HERE, or follow the mission on Facebook, Twitter and Instagram.

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Webb 101: 10 Facts about the James Webb Space Telescope

Did you know…?

1. Our upcoming James Webb Space Telescope will act like a powerful time machine – because it will capture light that’s been traveling across space for as long as 13.5 billion years, when the first stars and galaxies were formed out of the darkness of the early universe.

2. Webb will be able to see infrared light. This is light that is just outside the visible spectrum, and just outside of what we can see with our human eyes.

3. Webb’s unprecedented sensitivity to infrared light will help astronomers to compare the faintest, earliest galaxies to today's grand spirals and ellipticals, helping us to understand how galaxies assemble over billions of years.

Hubble’s infrared look at the Horsehead Nebula. Credit: NASA/ESA/Hubble Heritage Team

4. Webb will be able to see right through and into massive clouds of dust that are opaque to visible-light observatories like the Hubble Space Telescope. Inside those clouds are where stars and planetary systems are born.

5. In addition to seeing things inside our own solar system, Webb will tell us more about the atmospheres of planets orbiting other stars, and perhaps even find the building blocks of life elsewhere in the universe.

Credit: Northrop Grumman

6. Webb will orbit the Sun a million miles away from Earth, at the place called the second Lagrange point. (L2 is four times further away than the moon!)

7. To preserve Webb’s heat sensitive vision, it has a ‘sunshield’ that’s the size of a tennis court; it gives the telescope the equivalent of SPF protection of 1 million! The sunshield also reduces the temperature between the hot and cold side of the spacecraft by almost 600 degrees Fahrenheit.

8.  Webb’s 18-segment primary mirror is over 6 times bigger in area than Hubble's and will be ~100x more powerful. (How big is it? 6.5 meters in diameter.)

9.  Webb’s 18 primary mirror segments can each be individually adjusted to work as one massive mirror. They’re covered with a golf ball's worth of gold, which optimizes them for reflecting infrared light (the coating is so thin that a human hair is 1,000 times thicker!).

10. Webb will be so sensitive, it could detect the heat signature of a bumblebee at the distance of the moon, and can see details the size of a US penny at the distance of about 40 km.

BONUS!  Over 1,200 scientists, engineers and technicians from 14 countries (and more than 27 U.S. states) have taken part in designing and building Webb. The entire project is a joint mission between NASA and the European and Canadian Space Agencies. The telescope part of the observatory was assembled in the world’s largest cleanroom at our Goddard Space Flight Center in Maryland.

Webb is currently at Northrop Grumman where the telescope will be mated with the spacecraft and undergo final testing. Once complete, Webb will be packed up and be transported via boat to its launch site in French Guiana, where a European Space Agency Ariane 5 rocket will take it into space.

Learn more about the James Webb Space Telescope HERE, or follow the mission on Facebook, Twitter and Instagram.

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What’s Up for September 2017?

Set your sights beyond the solar system and take a late summertime road trip along the Milky Way!

On September 15 the Cassini spacecraft ends its glorious Saturnian science tour by plunging into the atmosphere of Saturn, becoming forever a part of the ringed planet. Learn more about the end of mission activities HERE. 

This month Saturn is the only prominent evening planet low in the southwest sky. 

Look for it near the constellation Sagittarius. Above and below Saturn--from a dark sky--you can't miss the summer Milky Way spanning the sky from northeast to southwest.

Grab a pair of binoculars and scan the teapot-shaped Sagittarius, where stars and some brighter clumps appear as steam from the teapot. Those bright clumps are near the center of our galaxy, which is full of gas, dust and stars.

Directly overhead is the great Summer Triangle of stars. Vega, Altair and Deneb are in the pretty constellations Lyra, Aquila and Cygnus.

As you gaze toward the northeast you'll see Cassiopeia, the familiar W-shaped constellation...and Perseus. Through your binoculars, look for the Perseus Double Cluster. Both of the clusters are visible with the naked eye, are 7500 light years away, and contain more than 300 blue-white super-giant stars!

Every star and every object you can see with your unaided eye is part of the Milky Way. With one exception: the great Andromeda galaxy, which is faintly visible through binoculars on the opposite side of the night sky from Saturn and the teapot.

You can find out about our missions studying the solar system and universe at: https://www.nasa.gov/topics/solarsystem/index.html

Watch the full What’s Up for September video: 

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The James Webb Space Telescope: A Story of Art & Science

Artists of all kinds were invited to apply for the chance to visit our Goddard Space Flight Center to be inspired by the giant, golden, fully-assembled James Webb Space Telescope mirror.

Art/Photo Credit: Jedidiah Dore

Webb has a mirror that is nearly 22 feet high and (to optimize it for infrared observations) is covered in a microscopic layer of actual gold.

Art/Photo Credit: Susan Lin

Because of Webb’s visually striking appearance, the project hosted a special viewing event on Wednesday, Nov. 2, 2016.

Photo Credit: Maggie Masetti

There was an overwhelming response to the event invitation and ultimately twenty-four people were selected to attend. They represented a broad range of artistic media and styles, including: watercolor, 3D printed sculpture, silk screening, acrylics, sumi-e (East Asian brush technique), comics, letterpress, woodwork, metalwork, jewelry making, fiber art, ink, mural painting, kite-making, tattooing, scientific illustration, poetry, songwriting, and video making.

Art/Photo Credit: Sue Reno

Project scientists and engineers spoke with visitors to give context to what they were seeing and explain why Webb is an engineering marvel, and how it will change our view of the universe. 

Among other things, Webb will see the first stars and galaxies that formed in the early universe and help us to better understand how planetary systems form and evolve. It will help us answer questions about who we, as humans, are and where we came from.

Art Credit: Jessica Lee Photo Credit: Maggie Masetti

The artists spent several hours sitting right in front of the telescope, where they sketched, painted, took photos and even filmed a music video.

Art Credit: Joanna Barnum Photo Credit: Maggie Masetti

While some of the pieces of art are finished, most of the artists went home with their heads full of ideas and sketchbooks full of notes. Stay tuned for more info on where you can see their final works displayed!

Art/Photo Credit: Susan Lin

Finished art from the event continues to be added HERE.

The James Webb Space Telescope is finishing environmental testing at our Goddard Space Flight Center in Greenbelt, Maryland. Next it will head to our Johnson Space Center in Houston for an end-to-end test at cryogenic temperatures. After that, it goes to Northrop Grumman to be mated with the giant tennis court-sized sunshield and the spacecraft bus.  The observatory will launch in October of 2018 from a European Space Agency (ESA) launch site in French Guiana, aboard an Ariane 5 rocket.  Webb is a collaboration of NASA, ESA, and the Canadian Space Agency (CSA).

Follow Webb on Facebook, Twitter and Instagram.

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10 “Out of This World" Facts About the James Webb Space Telescope

Wouldn’t it be neat to see a period of the universe’s history that we’ve never seen before? That’s exactly what the James Webb Space Telescope (JWST) will be able to do…plus more!

Specifically, Webb will see the first objects that formed as the universe cooled down after the Big Bang. We don’t know exactly when the universe made the first stars and galaxies – or how for that matter. That is what we are building Webb to help answer.

Here are 10 awesome facts about this next generation space telescope:

1. The James Webb Space Telescope is the world’s largest and next premier space observatory. It will extend the discoveries of the Hubble Space telescope and observe the birthplaces of stars, galaxies, planets and life over billions of years.

2. It is named after James Webb, NASA’s second administrator and champion of our science.

3. At 3 stories high and the size of a tennis court, it will be 100 times more powerful than Hubble!

4. It is so big that it has to fold origami-style to fit in the rocket, which is only 5.4 meters wide...And then it will unfurl, segment by segment, once in space.

5. The telescope will observe infrared light with unprecedented sensitivity. It will see the first galaxies born after the Big Bang over 13.5 billion years ago.

6. Webb's infrared cameras are so sensitive they must be shielded from light from the sun, Earth, and moon. The 5-layer sunshield is like having sunblock of SPF 1 million.

7. Webb will orbit the sun 1 million miles from Earth, where the telescope will operate at temperatures below -390 F (-235 C).

8. Webb’s mirrors are coated with a super thin layer of gold only about 1000 atoms thick to optimize their reflectivity in the infrared.

9. Webb will launch from French Guiana in 2018. It is launched near the equator because the faster spin of Earth there gives the rocket an extra push.

10. Webb is an international mission, with contributions from the European Space Agency and Canadian Space Agency. Once operational, scientists from all over the world will be able to use Webb to explore our solar system, planets outside our solar system, stars and galaxies.

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10 Times More Galaxies!

The universe suddenly looks a lot more crowded…

We already estimated that there were about 100 billion galaxies in the observable universe, but new research shows that this estimate is at least 10 times too low!

First, what is the observable universe? Well, it is the most distant part of the universe we can see from Earth because, in theory, the light from these objects have had time to reach Earth.

In a new study using surveys taken by the Hubble Space Telescope and other observatories, astronomers came to the surprising conclusion that there are at least 10 times more galaxies in the observable universe than previously thought. This places the universe’s estimated population at, minimally, 2 trillion galaxies!

The results have clear implications for galaxy formation, and also helps shed light on an ancient astronomical paradox – why is the sky dark at night?

Most of these newly discovered galaxies were relatively small and faint, with masses similar to those of the satellite galaxies surrounding the Milky Way.

Using deep-space images from the Hubble Space Telescope and other observatories, astronomers converted the images into 3-D, in order to make accurate measurements of the number of galaxies at different epochs in the universe’s history.

In addition, they used new mathematical models, which allowed them to infer the existence of galaxies that the current generation of telescopes cannot observe. This led to the surprising conclusion that in order for the numbers of galaxies we now see and their masses to add up, there must be a further 90% of galaxies in the observable universe that are too faint and too far away to be seen with present-day telescopes.

The myriad small faint galaxies from the early universe merged over time into the larger galaxies we can now observe.

That means that over 90% of the galaxies in the universe have yet to be studied! In the near future, the James Webb Space Telescope will be able to study these ultra-faint galaxies and give us more information about their existence.

So back to the question…Why is the sky dark at night if the universe contains an infinity of stars? Researchers came to the conclusion that indeed there actually is such an abundance of galaxies that, in principle, every patch in the sky contains part of a galaxy.

However, starlight from the galaxies is invisible to the human eye and most modern telescopes due to other known factors that reduce visible and ultraviolet light in the universe. Those factors are the reddening of light due to the expansion of space, the universe’s dynamic nature, and the absorption of light by intergalactic dust and gas. All combined, this keeps the night sky dark to our vision.

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