Best image yet of aging star's disc captured

February 11, 2016

Scott Kelly ‏(@StationCDRKelly): "Day 321. Beautiful #Earth. Beautiful #Africa. #GoodNight from @space_station! #YearInSpace"

February 11, 2016

A computer simulation shows the collision of two black holes, a tremendously powerful event detected for the first time ever by the Laser Interferometer Gravitational-Wave Observatory, or LIGO. LIGO detected gravitational waves, or ripples in space and time generated as the black holes spiraled in toward each other, collided, and merged. This simulation shows how the merger would appear to our eyes if we could somehow travel in a spaceship for a closer look. It was created by solving equations from Albert Einstein's general theory of relativity using the LIGO data.

This simulation was created by the multi-university SXS (Simulating eXtreme Spacetimes) project. For more information, visit www.black-holes.org. 

(Photo via SXS)

February 15, 2016

Scott Kelly ‏(@StationCDRKelly): "Lights of #HoChiMinhCity #Saigon #Vietnam. #YearInSpace"

February 24, 2016

This image of the Milky Way has been released to mark the completion of the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL). The APEX telescope in Chile has mapped the full area of the Galactic Plane visible from the southern hemisphere for the first time at submillimetre wavelengths — between infrared light and radio waves — and in finer detail than recent space-based surveys.

The APEX data, at a wavelength of 0.87 millimetres, shows up in red and the background blue image was imaged at shorter infrared wavelengths by the NASA Spitzer Space Telescope as part of the GLIMPSE survey. The fainter extended red structures come from complementary observations made by ESA's Planck satellite. Note that the far right section of this long and thin image does not include Planck imaging.

February 24, 2016

This image of the Milky Way has been released to mark the completion of the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL). The APEX telescope in Chile has mapped the full area of the Galactic Plane visible from the southern hemisphere for the first time at submillimetre wavelengths — between infrared light and radio waves — and in finer detail than recent space-based surveys.

The APEX data, at a wavelength of 0.87 millimetres, shows up in red and the background blue image was imaged at shorter infrared wavelengths by the NASA Spitzer Space Telescope as part of the GLIMPSE survey. The fainter extended red structures come from complementary observations made by ESA's Planck satellite. Note that the far right section of this long and thin image does not include Planck imaging.

February 26, 2016

Scott Kelly ‏(@StationCDRKelly): "#EarthArt Desert dunes. #YearInSpace"

February 26, 2016

Sparkling at the center of this beautiful NASA/ESA Hubble Space Telescope image is a Wolf–Rayet star known as WR 31a, located about 30,000 light-years away in the constellation of Carina (The Keel).

The distinctive blue bubble appearing to encircle WR 31a is a Wolf–Rayet nebula — an interstellar cloud of dust, hydrogen, helium and other gases. Created when speedy stellar winds interact with the outer layers of hydrogen ejected by Wolf–Rayet stars, these nebulae are frequently ring-shaped or spherical. The bubble — estimated to have formed around 20,000 years ago — is expanding at a rate of around 220,000 kilometers (136,700 miles) per hour!

Unfortunately, the lifecycle of a Wolf–Rayet star is only a few hundred thousand years — the blink of an eye in cosmic terms. Despite beginning life with a mass at least 20 times that of the sun, Wolf–Rayet stars typically lose half their mass in less than 100,000 years. And WR 31a is no exception to this case. It will, therefore, eventually end its life as a spectacular supernova, and the stellar material expelled from its explosion will later nourish a new generation of stars and planets.

(Photo via ESA/Hubble & NASA, Acknowledgement: Judy Schmidt, Caption via European Space Agency)

February 28, 2016

Scott Kelly ‏(@StationCDRKelly): "#Countdown 2 days & a wake-up! Getting closer to Earth & hope Mars too. #GoodNight from @space_station! #YearInSpace"

February 3, 2016

This wide-field view shows a spectacular region of dark and bright clouds, forming part of a region of star formation in the constellation of Ophiuchus (The Serpent Bearer). This picture was created from images in the Digitized Sky Survey 2.

February 19, 2016

Scott Kelly ‏(@StationCDRKelly): "Day 329. One night over #Macedonia. #GoodNight from @space_station! #YearInSpace"

February 16, 2016

Scott Kelly (‏@StationCDRKelly): "#ColorsofEarth Red and purple Terra Australis. #YearInSpace"

February 26, 2016

Aurora seen from the International Space Station by ESA astronaut Tim Peake.

Tim commented on the picture: "The ISS just passed straight through a thick green fog of aurora... eerie but very beautiful."

Tim's six-month mission to the International Space Station is named Principia, after Isaac Newton’s ground-breaking Naturalis Principia Mathematica, which describes the principal laws of motion and gravity.

He is performing more than 30 scientific experiments for ESA and taking part in numerous others from ESA’s international partners.

ESA and the UK Space Agency have partnered to develop many exciting educational activities around the Principia mission, aimed at sparking the interest of young children in science and space.

February 28, 2016

Scott Kelly ‏(@StationCDRKelly): "#Ice #YearInSpace"

February 11, 2016

NASA astronaut Peggy Whitson trains underwater for a spacewalk at the Neutral Buoyancy Laboratory (NBL) at Johnson Space Center in Houston. Whitson is scheduled to launch to the International Space Station in late 2016 as part of Expedition 50/51.

Dr. Whitson first traveled to the space station as a crew member of Expedition 5, launching aboard the space shuttle STS-111 mission and returning six months later on STS-113. She was named the first NASA Science Officer during her stay, and she conducted 21 investigations in human life sciences and microgravity sciences as well as commercial payloads. Whitson became the first woman to command the International Space Station in October 2007, leading Expedition 16 during a six-month stay on the orbiting laboratory.

(Photo by Bill Brassard (NBL) via NASA)

February 2, 2016

Scott Kelly ‏(@StationCDRKelly): "5K times around Earth can seem like #GroundhogDay but still a privilege. #GoodNight frm @space_station! #YearInSpace"

February 25, 2016

This ethereal scene captured by NASA’s New Horizons spacecraft tells yet another story of Pluto’s diversity of geological and compositional features—this time in an enhanced color image of the north polar area.

Long canyons run vertically across the polar area—part of the informally named Lowell Regio, named for Percival Lowell, who founded Lowell Observatory and initiated the search that led to Pluto’s discovery. The widest of the canyons (yellow in the image below) – is about 45 miles (75 kilometers) wide and runs close to the north pole. Roughly parallel subsidiary canyons to the east and west (in green) are approximately 6 miles (10 kilometers) wide. The degraded walls of these canyons appear to be much older than the more sharply defined canyon systems elsewhere on Pluto, perhaps because the polar canyons are older and made of weaker material. These canyons also appear to represent evidence for an ancient period of tectonics. 

A shallow, winding valley (in blue) runs the entire length of the canyon floor. To the east of these canyons, another valley (pink) winds toward the bottom-right corner of the image. The nearby terrain, at bottom right, appears to have been blanketed by material that obscures small-scale topographic features, creating a ‘softened’ appearance for the landscape. 

Large, irregularly-shaped pits (in red), reach 45 miles (70 kilometers) across and 2.5 miles (4 kilometers) deep, scarring the region. These pits may indicate locations where subsurface ice has melted or sublimated from below, causing the ground to collapse.

The color and composition of this region – shown in enhanced color – also are unusual.  High elevations show up in a distinctive yellow, not seen elsewhere on Pluto.  The yellowish terrain fades to a uniform bluish gray at lower elevations and latitudes. New Horizons' infrared measurements show methane ice is abundant across Lowell Regio, and there is relatively little nitrogen ice.  “One possibility is that the yellow terrains may correspond to older methane deposits that have been more processed by solar radiation than the bluer terrain,” said Will Grundy, New Horizons composition team lead from Lowell Observatory, Flagstaff, Arizona. 

(Photo via NASA/JHUAPL/SwRI)

February 12, 2016

Scott Kelly ‏(@StationCDRKelly): "#EarthArt #Iran #YearInSpace"

February 6, 2016

Scott Kelly ‏(@StationCDRKelly): "The cracking blue ice of the #Himalayas. Brilliant! #YearInSpace"

February 12, 2016

In this cosmic snapshot, the spectacularly symmetrical wings of Hen 2-437 show up in a magnificent icy blue hue. Hen 2-437 is a planetary nebula, one of around 3,000 such objects known to reside within the Milky Way.

Located within the faint northern constellation of Vulpecula (The Fox), Hen 2-437 was first identified in 1946 by Rudolph Minkowski, who later also discovered the famous and equally beautiful M2-9 (otherwise known as the Twin Jet Nebula). Hen 2-437 was added to a catalog of planetary nebula over two decades later by astronomer and NASA astronaut Karl Gordon Henize.

Planetary nebulae such as Hen 2-437 form when an aging low-mass star — such as the sun — reaches the final stages of life. The star swells to become a red giant, before casting off its gaseous outer layers into space. The star itself then slowly shrinks to form a white dwarf, while the expelled gas is slowly compressed and pushed outwards by stellar winds. As shown by its remarkably beautiful appearance, Hen 2-437 is a bipolar nebula — the material ejected by the dying star has streamed out into space to create the two icy blue lobes pictured here.

(Photo via ESA (European Space Agency)/Hubble & NASA, Acknowledgement: Judy Schmidt, Caption via ESA)

February 2, 2016

Scott Kelly ‏(@StationCDRKelly): "#CentralAmerica you were particularly brilliant this morning! #YearInSpace"

February 22, 2016

Scott Kelly (‏@StationCDRKelly): "Will be missing these sands too, but looking forward to sandy beaches up close. #EarthArt #Africa #YearInSpace"

February 20, 2016

Scott Kelly ‏(@StationCDRKelly): "Day 330. Tried to only count up. 10 days left tmrw I start #countdown! #GoodNight from @space_station! #YearInSpace"

February 1, 2016

The soft, bright-and-dark bands displayed by Saturn in this view from NASA's Cassini spacecraft are the signature of methane in the planet's atmosphere.

This image was taken in wavelengths of light that are absorbed by methane on Saturn. Dark areas are regions where light travels deeper into the atmosphere (passing through more methane) before reflecting and scattering off of clouds and then heading back out of the atmosphere. In such images, the deeper the light goes, the more of it gets absorbed by methane, and the darker that part of Saturn appears.

The moon Dione (698 miles or 1,123 kilometers across) hangs below the rings at right. Shadows of the rings are also visible here, cast onto the planet's southern hemisphere, in an inverse view compared to early in Cassini's mission at Saturn (see PIA08168).

This view looks toward the unilluminated side of the rings from about 0.3 degrees below the ringplane. The image was taken with the Cassini spacecraft wide-angle camera on Sept. 6, 2015, using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 728 nanometers.

(Photo via NASA/JPL-Caltech/Space Science Institute)

February 18, 2016

Images from NASA's New Horizons mission suggest that Pluto's largest moon, Charon, once had a subsurface ocean that has long since frozen and expanded, pushing out on the moon's surface and causing it to stretch and fracture on a massive scale.

The side of Charon viewed by the passing New Horizons spacecraft in July 2015 is characterized by a system of "pull apart" tectonic faults, which are expressed as ridges, scarps and valleys-the latter sometimes reaching more than 4 miles (6.5 kilometers) deep. Charon's tectonic landscape shows that, somehow, the moon expanded in its past, and –like Bruce Banner tearing his shirt as he becomes the Incredible Hulk -- Charon's surface fractured as it stretched.

Charon's outer layer is primarily water ice. When the moon was young this layer was warmed by the decay of radioactive elements, as well as Charon's own internal heat of formation. Scientists say Charon could have been warm enough to cause the water ice to melt deep down, creating a subsurface ocean. But as Charon cooled over time, this ocean would have frozen and expanded (as happens when water freezes), pushing the surface outward and producing the massive chasms we see today.

The top segment focuses on a section of the feature informally named Serenity Chasma, part of a vast equatorial belt of chasms on Charon. In fact, this system of chasms is one of the longest seen anywhere in the solar system, running at least 1,100 miles (about 1,800 kilometers) long and reaching 4.5 miles (7.5 kilometers) deep. By comparison, the Grand Canyon is 277 miles (446 kilometers) long and just over a mile (1.6 kilometers) deep.

The lower portion of the image shows color-coded topography of the same scene. Measurements of the shape of this feature tell scientists that Charon's water-ice layer may have been at least partially liquid in its early history, and has since refrozen.

February 26, 2016

The Sentinel-2A satellite takes us over central-eastern Egypt with this image from 17 January.

Like most of Egypt’s landscape, the image is dominated by arid desert – namely the Eastern Desert between the Nile River the Red Sea. The distinctive pattern of water erosion from rivers and streams is clearly visible as they make their way towards the Nile, at which point the rolling sandy highlands drop abruptly at the Nile valley, visible along the bottom of the image.

Fields of intensive farming along the Nile appear red owing to this false-colour image being processed to include the near-infrared. The varying shades of red indicate how sensitive the multispectral instrument on Sentinel-2 is to differences in chlorophyll content, providing key information on plant health.

The Nile valley is one of the world’s most densely populated areas. The river is the primary source of water for both Egypt and Sudan’s populations, supporting life in an otherwise uninhabitable environment, as evident by the stark contrast between the colours of this image.

Zooming in along the bottom we can see clusters of black dots where cities and towns are located, in addition to the fields. In the lower right, just above the red area, there is an interesting pattern of roads from our bird’s-eye view – possibly a developing residential area.

(Photo via Copernicus Sentinel data (2016)/ESA)

February 10, 2016

A newly formed star lights up the surrounding cosmic clouds in this image from ESO’s La Silla Observatory in Chile. Dust particles in the vast clouds that surround the star HD 97300 diffuse its light, like a car headlight in enveloping fog, and create the reflection nebula IC 2631. Although HD 97300 is in the spotlight for now, the very dust that makes it so hard to miss heralds the birth of additional, potentially scene-stealing, future stars.

(Photo via ESO)

February 1, 2016

Scott Kelly (‏@StationCDRKelly): "#goodmorning #February! My 11th full month is space! Thanks for having an extra day! #LeapYear2016 #YearInSpace!"

February 22, 2016

Scott Kelly (‏@StationCDRKelly): "I'm going to miss the colors of #Africa! #EarthArt. #YearInSpace"

February 18, 2016

This perspective view in Arda Valles was generated from the main camera’s stereo channels on ESA’s Mars Express. The image focuses on a 25 km-wide impact crater filled with sediments, that have subsequently collapsed into chaotic terrain. The jumbled nodules in the crater rim probably indicate the former level of the infilling sediments.

A number of fracture-like features appear to extend out to the smoother basin floor to the right. They could be a later manifestation of stresses due to subsidence or compaction of surface materials.

(Photo via ESA)

February 1, 2016

The spiral galaxy NGC 986 in the constellation of Fornax (The Furnace). The galaxy, which was discovered in 1826 by the Scottish astronomer James Dunlop, is not often imaged due to its proximity to the famous and rich Fornax Cluster of galaxies. Which is a shame, as this galaxy is not only a great scientific object, but also very pretty.

The galaxy is about 56 million light-years away and seen almost perfectly from the top, or — as astronomers say — face-on. This allows us to see the two main spiral arms and also a central bar-shaped structure, composed of stars and dust, which makes it a barred spiral galaxy.

(Photo via ESO)

February 15, 2016

Scott Kelly ‏(@StationCDRKelly): "Day 325. Set your sails for the #stars! #GoodNight from @space_station! #YearInSpace"

February 10, 2016

Wind is one of the most active forces shaping Mars' surface in today's climate. The wind has carved the features we call "yardangs," one of many in this scene, and deposited sand on the floor of shallow channels between them.

On the sand, the wind forms ripples and small dunes. In Mars' thin atmosphere, light is not scattered much, so the shadows cast by the yardangs are sharp and dark. (Note: The cutout is not map-projected, so approximate north is down).

(Photo via NASA/JPL-Caltech/Univ. of Arizona)

February 14, 2016

Scott Kelly ‏(@StationCDRKelly): "That #polarvortex even looks cold from here! #Burr! #YearInSpace"

February 9, 2016

Scott Kelly ‏(@StationCDRKelly): "#fuji san, your majesty casts a wide shadow! #Japan YearInSpace!"

February 19, 2016

Tim Peake ‏(@astro_timpeake): "Farewell #Cygnus – you served us well! #ISScargo"

February 5, 2016

This image, taken by the NASA/ESA Hubble Space Telescope, shows a peculiar galaxy known as NGC 1487, lying about 30 million light-years away in the southern constellation of Eridanus.

Rather than viewing it as a celestial object, it is actually better to think of this as an event. Here, we are witnessing two or more galaxies in the act of merging together to form a single new galaxy. Each galaxy has lost almost all traces of its original appearance, as stars and gas have been thrown by gravity in an elaborate cosmic whirl.

Unless one is very much bigger than the other, galaxies are always disrupted by the violence of the merging process. As a result, it is very difficult to determine precisely what the original galaxies looked like and, indeed, how many of them there were. In this case, it is possible that we are seeing the merger of several dwarf galaxies that were previously clumped together in a small group.

Although older yellow and red stars can be seen in the outer regions of the new galaxy, its appearance is dominated by large areas of bright blue stars, illuminating the patches of gas that gave them life. This burst of star formation may well have been triggered by the merger.

(Photo via ESA/Hubble & NASA, Acknowledgement: Judy Schmidt, Caption via European Space Agency)

February 22, 2016

Scott Kelly ‏(@StationCDRKelly): "More #Africa #EarthArt hues. #YearInSpace"

February 7, 2016

Scott Kelly ‏(@StationCDRKelly): "Got to see the #SuperBowl in person after all! But at 17,500MPH, it didn't last long. #YearInSpace"

February 23, 2016

Scott Kelly (‏@StationCDRKelly): "#Countdown Counting #stars and days. 7 days and a wake up! #GoodNight from @space_station! #YearInSpace"

February 11, 2016

Scott Kelly ‏(@StationCDRKelly): "Good afternoon #Egypt! Hope to see you up close some day. #YearInSpace"

February 17, 2016

Sentinel-3A – the first in the two-satellite Sentinel-3 mission – lifted off on a Rocket launcher from the Plesetsk Cosmodrome in northern Russia at 17:57 GMT (18:57 CET) on 16 February 2016.

(Photo via ESA–Stephane Corvaja, 2016)

February 12, 2016

Scott Kelly (‏@StationCDRKelly): "The snowy foothills of #Iran. #YearInSpace"

February 8, 2016

Scott Kelly ‏(@StationCDRKelly): "Day 318. Over a #Shanghai night. Wishes for a happy #ChineseNewYear! #GoodNight from @space_station! #YearInSpace"

February 1, 2016

Straight lines do not often crop up in space. Whenever they do, they seem somehow incongruous and draw our attention. The Red Rectangle is one such mystery object.

It first caught astronomers’ attention in 1973. The star HD 44179 had been known since 1915 to be double, but it was only when a rocket flight carrying an infrared detector was turned its way that the red rectangle revealed itself.

This image was taken later, in 2007, by the Hubble Space Telescope’s Advanced Camera for Surveys. It focuses on wavelengths of red light, in particular highlighting the emission from hydrogen gas.

This particular emission has been displayed in red. A second, broader range of orange–red light has also been recorded, and, to increase the contrast, this light has been colour coded blue on the image.

The Red Rectangle is some 2300 light-years away in the constellation of Monoceros. It arises because one of the stars in HD 44179 is in the last stages of its life. It has puffed up as the nuclear reactions at its core have faltered, and this has resulted in it shedding its outer layers into space.

Such a cloud of gas is known erroneously as a planetary nebula because Hanoverian astronomer William Herschel thought they look a bit like the pale disc of Uranus, the planet he had discovered.

The X-shape revealed in this image suggests that something is preventing the uniform expansion of the star’s atmosphere. Instead, a thick disc of dust probably surrounds the star, funnelling the outflow into two wide cones. The edges of these show up as the diagonal lines. Thankfully, while that explains the mystery of the object, it does not detract from its unearthly beauty.

(Photo via ESA/Hubble and NASA)

February 10, 2016

The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Aqua satellite captured this image of cloud streets and sea ice in the Sea of Okhotsk on Feb. 8, 2016. Cloud streets are long parallel bands of cumulus clouds that form when cold air blows over warmer waters and a warmer air layer (temperature inversion) rests over the top of both.

(Photo via NASA image courtesy LANCE/EOSDIS MODIS Rapid Response Team at NASA GSFC)

February 2, 2016

Expedition 46 flight engineer Tim Peake of ESA captured this photo on Jan. 29, 2016 from the International Space Station, as the robotic arm in Japan's Kibo laboratory successfully deployed two combined satellites from Texas universities. The pair of satellites -- AggieSat4 built by Texas A&M University students, and BEVO-2 built by University of Texas students -- together form the Low Earth Orbiting Navigation Experiment for Spacecraft Testing Autonomous Rendezvous and Docking (LONESTAR) investigation.

The satellites will demonstrate communication protocols between them and with ground stations, as well as systems that allow the satellites to navigate through space and relative to each other and to orient themselves in three dimensions. Flight demonstration of these abilities, necessary for unmanned craft to be able to rendezvous and dock in space without direct human intervention, will contribute to future satellite missions as well.

(Photo via ESA/NASA)

February 25, 2016

Scott Kelly ‏(@StationCDRKelly): "5 days & a wake-up! Every #mountain top is within reach. Keep climbing. #GoodNight from @space_station! #YearInSpace"

February 3, 2016

Scott Kelly ‏(@StationCDRKelly): "Our cosmonaut colleagues, Yuri and Sergei are doing a spacewalk right now. Good luck and be safe! #YearInSpace"

February 14, 2016

Scott Kelly ‏(@StationCDRKelly): "Nursed the #SpaceFlowers all the way to today and now all that remains are memories. Happy #Valentines Day!"

February 28, 2016

Scott Kelly (‏@StationCDRKelly): "#Water #YearInSpace"

February 19, 2016

Surrounded by an envelope of dust, the subject of this NASA/ESA Hubble Space Telescope image is a young forming star known as HBC 1. The star is in an immature and adolescent phase of life, while most of a sun-like star’s life is spent in a stable stage comparable to human adulthood.

In this view, HBC 1 illuminates a wispy reflection nebula known as IRAS 00044+6521. Formed from clouds of interstellar dust, reflection nebulae do not emit any visible light of their own.  Instead, like fog encompassing a lamppost, they shine via the light reflected off the dust from the stars embedded within. Though nearby stars cannot ionize the nebula’s dust, as they can for gas within brighter emission nebulae, scattered starlight can make the dust visible in a reflection nebula.

(Photo via ESA/Hubble & NASA, Acknowledgement: Judy Schmidt, Caption via European Space Agency)

February 26, 2016

Scott Kelly ‏(@StationCDRKelly): "Snow and ice make #Canada #EarthArt nice. #YearInSpace"

February 21, 2016

Tim Peake ‏(@astro_timpeake): "A large cloud of sand and dust hangs over #Spain and #Portugal today #Principia"

February 4, 2016

Tim Peake ‏(@astro_timpeake): "New Zealand looking stunning in the sunshine! #NewZealand"

February 22, 2016

Three of Saturn's moons -- Tethys, Enceladus and Mimas -- are captured in this group photo from NASA's Cassini spacecraft.

Tethys (660 miles or 1,062 kilometers across) appears above the rings, while Enceladus (313 miles or 504 kilometers across) sits just below center. Mimas (246 miles or 396 kilometers across) hangs below and to the left of Enceladus.

This view looks toward the sunlit side of the rings from about 0.4 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Dec. 3, 2015.

(Photo via NASA/JPL-Caltech/Space Science Institute)

February 4, 2016

The nitrogen ice glaciers on Pluto appear to carry an intriguing cargo: numerous, isolated hills that may be fragments of water ice from Pluto’s surrounding uplands. These hills individually measure one to several miles or kilometers across, according to images and data from NASA’s New Horizons mission.

The hills, which are in the vast ice plain informally named Sputnik Planum within Pluto’s ‘heart,’ are likely miniature versions of the larger, jumbled mountains on Sputnik Planum’s western border. They are yet another example of Pluto’s fascinating and abundant geological activity.

(Photo via NASA/JHUAPL/SwRI)

February 17, 2016

Scott Kelly (‏@StationCDRKelly): "Day 327. A sky full of #stars and Earth aglow below. #GoodNight from @space_station! #YearInSpace"

February 16, 2016

Scott Kelly ‏(@StationCDRKelly): "#ColorsOfEarth Green sea. #YearInSpace"

February 23, 2016

This image taken Jan. 14, 2015, acquired by the Operational Land Imager (OLI) on Landsat 8, shows the glaciers of Sierra de Sangra, an icy stratovolcano spanning the border of Chile and Argentina. Snow and ice are blue in these false-color images, which use different wavelengths to better differentiate areas of ice, rock, and vegetation.

Since the end of the Little Ice Age, the ice fields of Patagonia and other parts of South America have been shrinking as global temperatures have increased. A number of studies have investigated these changes, which can affect the communities downstream that rely on the glaciers for a steady water supply.

(Photo via NASA/Landsat 8)

February 1, 2016

Scott Kelly ‏(@StationCDRKelly): "Day 311. When you think of beautiful things. Don't forget Earth. #GoodNight from @space_station! #YearInSpace"