How Well Do You Know Neptune?

Chandra X-Ray Observatory, We Appreciate You

On July 23, 1999, the Space Shuttle Columbia blasted off from the Kennedy Space Center carrying the Chandra X-ray Observatory. In the two decades that have passed, Chandra’s powerful and unique X-ray eyes have contributed to a revolution in our understanding of the cosmos.

Since its launch 20 years ago, Chandra's unrivaled X-ray vision has changed the way we see the universe.

Chandra has captured galaxy clusters – the largest gravitationally bound objects in the universe – in the process of merging.

Chandra has shown us the powerful wind and shock fronts that rumble through star-forming systems.

And a star school, so to speak -- home to thousands of the Milky Way's biggest and brightest.

Carl Sagan said, "We are made of star-stuff." It's true. Most of the elements necessary for life are forged inside stars and blasted into interstellar space by supernovas. Chandra has tracked them.

Thank you Chandra X-Ray! To more adventures with you!

Check out Chandra’s 20th anniversary page to see how they are celebrating.

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A simulated image of NASA’s Nancy Grace Roman Space Telescope’s future observations toward the center of our galaxy, spanning less than 1 percent of the total area of Roman’s Galactic Bulge Time-Domain Survey. The simulated stars were drawn from the Besançon Galactic Model.

Exploring the Changing Universe with the Roman Space Telescope

The view from your backyard might paint the universe as an unchanging realm, where only twinkling stars and nearby objects, like satellites and meteors, stray from the apparent constancy. But stargazing through NASA’s upcoming Nancy Grace Roman Space Telescope will offer a front row seat to a dazzling display of cosmic fireworks sparkling across the sky.

Roman will view extremely faint infrared light, which has longer wavelengths than our eyes can see. Two of the mission’s core observing programs will monitor specific patches of the sky. Stitching the results together like stop-motion animation will create movies that reveal changing objects and fleeting events that would otherwise be hidden from our view.

Watch this video to learn about time-domain astronomy and how time will be a key element in NASA’s Nancy Grace Roman Space Telescope’s galactic bulge survey. Credit: NASA’s Goddard Space Flight Center

This type of science, called time-domain astronomy, is difficult for telescopes that have smaller views of space. Roman’s large field of view will help us see huge swaths of the universe. Instead of always looking at specific things and events astronomers have already identified, Roman will be able to repeatedly observe large areas of the sky to catch phenomena scientists can't predict. Then astronomers can find things no one knew were there!

One of Roman’s main surveys, the Galactic Bulge Time-Domain Survey, will monitor hundreds of millions of stars toward the center of our Milky Way galaxy. Astronomers will see many of the stars appear to flash or flicker over time.

This animation illustrates the concept of gravitational microlensing. When one star in the sky appears to pass nearly in front of another, the light rays of the background source star are bent due to the warped space-time around the foreground star. The closer star is then a virtual magnifying glass, amplifying the brightness of the background source star, so we refer to the foreground star as the lens star. If the lens star harbors a planetary system, then those planets can also act as lenses, each one producing a short change in the brightness of the source. Thus, we discover the presence of each exoplanet, and measure its mass and how far it is from its star. Credit: NASA's Goddard Space Flight Center Conceptual Image Lab 

That can happen when something like a star or planet moves in front of a background star from our point of view. Because anything with mass warps the fabric of space-time, light from the distant star bends around the nearer object as it passes by. That makes the nearer object act as a natural magnifying glass, creating a temporary spike in the brightness of the background star’s light. That signal lets astronomers know there’s an intervening object, even if they can’t see it directly.

This artist’s concept shows the region of the Milky Way NASA’s Nancy Grace Roman Space Telescope’s Galactic Bulge Time-Domain Survey will cover – relatively uncharted territory when it comes to planet-finding. That’s important because the way planets form and evolve may be different depending on where in the galaxy they’re located. Our solar system is situated near the outskirts of the Milky Way, about halfway out on one of the galaxy’s spiral arms. A recent Kepler Space Telescope study showed that stars on the fringes of the Milky Way possess fewer of the most common planet types that have been detected so far. Roman will search in the opposite direction, toward the center of the galaxy, and could find differences in that galactic neighborhood, too.

Using this method, called microlensing, Roman will likely set a new record for the farthest-known exoplanet. That would offer a glimpse of a different galactic neighborhood that could be home to worlds quite unlike the more than 5,500 that are currently known. Roman’s microlensing observations will also find starless planets, black holes, neutron stars, and more!

This animation shows a planet crossing in front of, or transiting, its host star and the corresponding light curve astronomers would see. Using this technique, scientists anticipate NASA’s Nancy Grace Roman Space Telescope could find 100,000 new worlds. Credit: NASA’s Goddard Space Flight Center/Chris Smith (USRA/GESTAR)

Stars Roman sees may also appear to flicker when a planet crosses in front of, or transits, its host star as it orbits. Roman could find 100,000 planets this way! Small icy objects that haunt the outskirts of our own solar system, known as Kuiper belt objects, may occasionally pass in front of faraway stars Roman sees, too. Astronomers will be able to see how much water the Kuiper belt objects have because the ice absorbs specific wavelengths of infrared light, providing a “fingerprint” of its presence. This will give us a window into our solar system’s early days.

This animation visualizes a type Ia supernova.

Roman’s High Latitude Time-Domain Survey will look beyond our galaxy to hunt for type Ia supernovas. These exploding stars originate from some binary star systems that contain at least one white dwarf – the small, hot core remnant of a Sun-like star. In some cases, the dwarf may siphon material from its companion. This triggers a runaway reaction that ultimately detonates the thief once it reaches a specific point where it has gained so much mass that it becomes unstable.

NASA’s upcoming Nancy Grace Roman Space Telescope will see thousands of exploding stars called supernovae across vast stretches of time and space. Using these observations, astronomers aim to shine a light on several cosmic mysteries, providing a window onto the universe’s distant past. Credit: NASA’s Goddard Space Flight Center

Since these rare explosions each peak at a similar, known intrinsic brightness, astronomers can use them to determine how far away they are by simply measuring how bright they appear. Astronomers will use Roman to study the light of these supernovas to find out how quickly they appear to be moving away from us.

By comparing how fast they’re receding at different distances, scientists can trace cosmic expansion over time. This will help us understand whether and how dark energy – the unexplained pressure thought to speed up the universe’s expansion – has changed throughout the history of the universe.

NASA’s Nancy Grace Roman Space Telescope will survey the same areas of the sky every few days. Researchers will mine this data to identify kilonovas – explosions that happen when two neutron stars or a neutron star and a black hole collide and merge. When these collisions happen, a fraction of the resulting debris is ejected as jets, which move near the speed of light. The remaining debris produces hot, glowing, neutron-rich clouds that forge heavy elements, like gold and platinum. Roman’s extensive data will help astronomers better identify how often these events occur, how much energy they give off, and how near or far they are.

And since this survey will repeatedly observe the same large vista of space, scientists will also see sporadic events like neutron stars colliding and stars being swept into black holes. Roman could even find new types of objects and events that astronomers have never seen before!

Learn more about the exciting science Roman will investigate on X and Facebook.

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What does it feel like to float?? Do you have trouble adjusting to walking on the earth after that ??

Why are bacteria resistant polymers being experimented, specifically in microgravity?

Caution: Universe Work Ahead 🚧

We only have one universe. That’s usually plenty – it’s pretty big after all! But there are some things scientists can’t do with our real universe that they can do if they build new ones using computers.

The universes they create aren’t real, but they’re important tools to help us understand the cosmos. Two teams of scientists recently created a couple of these simulations to help us learn how our Nancy Grace Roman Space Telescope sets out to unveil the universe’s distant past and give us a glimpse of possible futures.

Caution: you are now entering a cosmic construction zone (no hard hat required)!

This simulated Roman deep field image, containing hundreds of thousands of galaxies, represents just 1.3 percent of the synthetic survey, which is itself just one percent of Roman's planned survey. The full simulation is available here. The galaxies are color coded – redder ones are farther away, and whiter ones are nearer. The simulation showcases Roman’s power to conduct large, deep surveys and study the universe statistically in ways that aren’t possible with current telescopes.

One Roman simulation is helping scientists plan how to study cosmic evolution by teaming up with other telescopes, like the Vera C. Rubin Observatory. It’s based on galaxy and dark matter models combined with real data from other telescopes. It envisions a big patch of the sky Roman will survey when it launches by 2027. Scientists are exploring the simulation to make observation plans so Roman will help us learn as much as possible. It’s a sneak peek at what we could figure out about how and why our universe has changed dramatically across cosmic epochs.

This video begins by showing the most distant galaxies in the simulated deep field image in red. As it zooms out, layers of nearer (yellow and white) galaxies are added to the frame. By studying different cosmic epochs, Roman will be able to trace the universe's expansion history, study how galaxies developed over time, and much more.

As part of the real future survey, Roman will study the structure and evolution of the universe, map dark matter – an invisible substance detectable only by seeing its gravitational effects on visible matter – and discern between the leading theories that attempt to explain why the expansion of the universe is speeding up. It will do it by traveling back in time…well, sort of.

Seeing into the past

Looking way out into space is kind of like using a time machine. That’s because the light emitted by distant galaxies takes longer to reach us than light from ones that are nearby. When we look at farther galaxies, we see the universe as it was when their light was emitted. That can help us see billions of years into the past. Comparing what the universe was like at different ages will help astronomers piece together the way it has transformed over time.

This animation shows the type of science that astronomers will be able to do with future Roman deep field observations. The gravity of intervening galaxy clusters and dark matter can lens the light from farther objects, warping their appearance as shown in the animation. By studying the distorted light, astronomers can study elusive dark matter, which can only be measured indirectly through its gravitational effects on visible matter. As a bonus, this lensing also makes it easier to see the most distant galaxies whose light they magnify.

The simulation demonstrates how Roman will see even farther back in time thanks to natural magnifying glasses in space. Huge clusters of galaxies are so massive that they warp the fabric of space-time, kind of like how a bowling ball creates a well when placed on a trampoline. When light from more distant galaxies passes close to a galaxy cluster, it follows the curved space-time and bends around the cluster. That lenses the light, producing brighter, distorted images of the farther galaxies.

Roman will be sensitive enough to use this phenomenon to see how even small masses, like clumps of dark matter, warp the appearance of distant galaxies. That will help narrow down the candidates for what dark matter could be made of.

In this simulated view of the deep cosmos, each dot represents a galaxy. The three small squares show Hubble's field of view, and each reveals a different region of the synthetic universe. Roman will be able to quickly survey an area as large as the whole zoomed-out image, which will give us a glimpse of the universe’s largest structures.

Constructing the cosmos over billions of years

A separate simulation shows what Roman might expect to see across more than 10 billion years of cosmic history. It’s based on a galaxy formation model that represents our current understanding of how the universe works. That means that Roman can put that model to the test when it delivers real observations, since astronomers can compare what they expected to see with what’s really out there.

In this side view of the simulated universe, each dot represents a galaxy whose size and brightness corresponds to its mass. Slices from different epochs illustrate how Roman will be able to view the universe across cosmic history. Astronomers will use such observations to piece together how cosmic evolution led to the web-like structure we see today.

This simulation also shows how Roman will help us learn how extremely large structures in the cosmos were constructed over time. For hundreds of millions of years after the universe was born, it was filled with a sea of charged particles that was almost completely uniform. Today, billions of years later, there are galaxies and galaxy clusters glowing in clumps along invisible threads of dark matter that extend hundreds of millions of light-years. Vast “cosmic voids” are found in between all the shining strands.

Astronomers have connected some of the dots between the universe’s early days and today, but it’s been difficult to see the big picture. Roman’s broad view of space will help us quickly see the universe’s web-like structure for the first time. That’s something that would take Hubble or Webb decades to do! Scientists will also use Roman to view different slices of the universe and piece together all the snapshots in time. We’re looking forward to learning how the cosmos grew and developed to its present state and finding clues about its ultimate fate.

This image, containing millions of simulated galaxies strewn across space and time, shows the areas Hubble (white) and Roman (yellow) can capture in a single snapshot. It would take Hubble about 85 years to map the entire region shown in the image at the same depth, but Roman could do it in just 63 days. Roman’s larger view and fast survey speeds will unveil the evolving universe in ways that have never been possible before.

Roman will explore the cosmos as no telescope ever has before, combining a panoramic view of the universe with a vantage point in space. Each picture it sends back will let us see areas that are at least a hundred times larger than our Hubble or James Webb space telescopes can see at one time. Astronomers will study them to learn more about how galaxies were constructed, dark matter, and much more.

The simulations are much more than just pretty pictures – they’re important stepping stones that forecast what we can expect to see with Roman. We’ve never had a view like Roman’s before, so having a preview helps make sure we can make the most of this incredible mission when it launches.

Learn more about the exciting science this mission will investigate on Twitter and Facebook.

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DYK the bright clusters and nebulae of planet Earth's night sky are often named for flowers or insects? 

Though its wingspan covers over 3 light-years, NGC 6302: The Butterfly Nebula is no exception! With an estimated surface temperature of about 250,000 degrees C, the dying central star of this particular planetary nebula has become exceptionally hot, shining brightly in ultraviolet light but hidden from direct view by a dense torus of dust. This sharp close-up was recorded by the Hubble Space Telescope in 2009. The Hubble image data is reprocessed here, showing off the remarkable details of the complex planetary nebula.

Image Credit: NASA, ESA, Hubble, HLA; Reprocessing & Copyright: Robert Eder

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A Tour of our Moon

Want to go to the Moon? 

Let our Lunar Reconnaissance Orbiter take you there!

Our lunar orbiter, also known as LRO, has been collecting data on lunar topography, temperature, resources, solar radiation, and geology since it launched nine years ago. Our latest collection of this data is now in 4K resolution. This updated "Tour of the Moon" takes you on a virtual tour of our nearest neighbor in space, with new science updates from the vastly expanded data trove.

Orientale Basin

First stop, Orientale Basin located on the rim of the western nearside. It's about the size of Texas and is the best-preserved impact structure on the Moon. Topography data from LRO combined with gravity measurements from our twin GRAIL spacecraft reveal the structure below the surface and help us understand the geologic consequences of large impacts.

South-Pole and Shackleton Crater

Unlike Earth, the Moon's axis is barely tilted relative to the Sun. This means that there are craters at the poles where the sunlight never reaches, called permanently shadowed regions. As a result, the Moon's South Pole has some of the coldest measured places in the solar system. How cold? -410 degrees F.

Because these craters are so cold and dark, water that happens to find its way into them never has the opportunity to evaporate. Several of the instruments on LRO have found evidence of water ice, which you can see in the highlighted spots in this visualization.

South-Pole Aitken Basin

South Pole-Aitken Basin is the Moon's largest, deepest and oldest observed impact structure. Its diameter is about 2,200 km or 1,367 miles across and takes up 1/4 of the Moon! If there was a flat, straight road and you were driving 60 mph, it would take you about 22 hours to drive across. And the basin is so deep that nearly two Mount Everests stacked on each other would fit from the bottom of the basin to the rim. South-Pole Aitken Basin is a top choice for a landing site on the far side of the Moon.

Tycho Crater

Now let's go to the near side. Tycho Crater is 100 million years young. Yes, that's young in geologic time. The central peak of the impact crater likely formed from material that rebounded back up after being compressed in the impact, almost like a spring. Check out that boulder on top. It looks small in this image, but it could fill a baseball stadium.

Aristarchus Plateau

Also prominent on the nearside is the Aristarchus Plateau. It features a crater so bright that you could see it with your naked eye from Earth! The Aristarchus Plateau is particularly interesting to our scientists because it reveals much of the Moon's volcanic history. The region is covered in rocks from volcanic eruptions and the large river-like structure is actually a channel made from a long-ago lava flow.

Apollo 17 Landing Site

As much as we study the Moon looking for sites to visit, we also look back at places we've already been. This is because the new data that LRO is gathering helps us reinterpret the geology of familiar places, giving scientists a better understanding of the sequence of events in early lunar history.

Here, we descend to the Apollo 17 landing site in the Taurus-Littrow valley, which is deeper than the Grand Canyon. The LRO camera is even able to capture a view of the bottom half of the Apollo 17 Lunar Lander, which still sits on the surface, as well as the rover vehicle. These images help preserve our accomplishment of human exploration on the Moon's surface.

North Pole

Finally, we reach the North Pole. Like the South Pole, there are areas that are in permanent shadow and others that bask in nearly perpetual light. LRO scientists have taken detailed brightness and terrain measurements of the North Pole in order to model these areas of sunlight and shadow through time.  Sunlit peaks and crater rims here may be ideal locations for generating solar power for future expeditions to the Moon.

LRO was designed as a one-year mission. Now in its ninth year, the spacecraft and the data emphasize the power of long-term data collection. Thanks to its many orbits around the Moon, we have been able to expand on lunar science from the Apollo missions while paving the way for future lunar exploration. And as the mission continues to gather data, it will provide us with many more opportunities to take a tour of our Moon. 

And HERE's the full “Tour of the Moon” video:

We hope you enjoyed the tour. If you'd like to explore the moon further, please visit moon.nasa.gov and moontrek.jpl.nasa.gov.

Make sure to follow @NASAMoon on Twitter for the latest lunar updates and photos.

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SHAKE IT UP! The Orion Exploration Mission-1 crew module was blasted with 141 decibels of acoustic energy to make sure parts don’t come loose when exposed to extreme vibrations experienced at launch. Don’t try this at home.  

Are we able to take a picture of it

Yup and I hope you share your photos with us on the NASA Eclipse Flicker page! https://www.flickr.com/groups/nasa-eclipse2017/ You can find out about how to safely take photos of the eclipse at https://www.nasa.gov/feature/goddard/2017/five-tips-from-nasa-for-photographing-the-total-solar-eclipse-on-aug-21 Good luck! 

What’s it like having the coolest job ever?