Great Barrier Reef Near Whitsunday Islands

An astronaut aboard the International Space Station used a powerful lens to photograph these three reefs in Australia’s Great Barrier Reef on Oct. 12, 2015. Reefs are easy to spot from space because the iridescent blues of shallow lagoons contrast sharply with the dark blues of deep water. via NASA http://ift.tt/1P1a2Iu

Valles Marineris: The Grand Canyon of Mars

Mars will look good in Earth's skies over the next few days -- but not this good. To get a view this amazing, a spacecraft had to actually visit the red planet. Running across the image center, though, is one the largest canyons in the Solar System. Named Valles Marineris, the grand valley extends over 3,000 kilometers long, spans as much as 600 kilometers across, and delves as much as 8 kilometers deep. By comparison, the Earth's Grand Canyon in Arizona, USA is 800 kilometers long, 30 kilometers across, and 1.8 kilometers deep. The origin of the Valles Marineris remains unknown, although a leading hypothesis holds that it started as a crack billions of years ago as the planet cooled. Several geologic processes have been identified in the canyon. The featured mosaic was created from over 100 images of Mars taken by Viking Orbiters in the 1970s. Tomorrow, Mars and Earth will pass the closest in 11 years, resulting in the red planet being quite noticeable toward the southeast after sunset. via NASA http://ift.tt/24eIt5s

Cat s Eye Wide and Deep

The Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its more familiar outlines are seen in the brighter central region of the nebula in this impressive wide-angle view. But the composite image combines many short and long exposures to also reveal an extremely faint outer halo. At an estimated distance of 3,000 light-years, the faint outer halo is over 5 light-years across. Planetary nebulae have long been appreciated as a final phase in the life of a sun-like star. More recently, some planetary nebulae are found to have halos like this one, likely formed of material shrugged off during earlier episodes in the star's evolution. While the planetary nebula phase is thought to last for around 10,000 years, astronomers estimate the age of the outer filamentary portions of this halo to be 50,000 to 90,000 years. Visible on the left, some 50 million light-years beyond the watchful planetary nebula, lies spiral galaxy NGC 6552. via NASA http://ift.tt/1XXfRhn

The Great Carina Nebula

A jewel of the southern sky, the Great Carina Nebula, also known as NGC 3372, spans over 300 light-years, one of our galaxy's largest star forming regions. Like the smaller, more northerly Great Orion Nebula, the Carina Nebula is easily visible to the unaided eye, though at a distance of 7,500 light-years it is some 5 times farther away. This gorgeous telescopic close-up reveals remarkable details of the region's central glowing filaments of interstellar gas and obscuring cosmic dust clouds. The field of view is over 50 light-years across. The Carina Nebula is home to young, extremely massive stars, including the stars of open cluster Trumpler 14 (below and right of center) and the still enigmatic variable Eta Carinae, a star with well over 100 times the mass of the Sun. Eta Carinae is the brightest star, seen here just above the dusty Keyhole Nebula (NGC 3324). While Eta Carinae itself maybe on the verge of a supernova explosion, X-ray images indicate that the Great Carina Nebula has been a veritable supernova factory. via NASA http://ift.tt/1ORra3a

Scott Kelly's Post-Flight Visit to Washington

Former NASA astronaut Scott Kelly speaks about his historic mission aboard the International Space Station during an event at the United States Capitol Visitor Center, Wednesday, May 25, 2016, in Washington. via NASA http://ift.tt/1sfuKiW

IC 5067 in the Pelican Nebula

The prominent ridge of emission featured in this sharp, colorful skyscape is cataloged as IC 5067. Part of a larger emission nebula with a distinctive shape, popularly called The Pelican Nebula, the ridge spans about 10 light-years following the curve of the cosmic pelican's head and neck. This false-color view also translates the pervasive glow of narrow emission lines from atoms in the nebula to a color palette made popular in Hubble Space Telescope images of star forming regions. Fantastic, dark shapes inhabiting the 1/2 degree wide field are clouds of cool gas and dust sculpted by the winds and radiation from hot, massive stars. Close-ups of some of the sculpted clouds show clear signs of newly forming stars. The Pelican Nebula, itself cataloged as IC 5070, is about 2,000 light-years away. To find it, look northeast of bright star Deneb in the high flying constellation Cygnus. via NASA http://ift.tt/1qLt7rO

Chasma Boreale and North Polar Ice Cap of Mars

Mars has bright polar caps of ice that are easily visible from telescopes on Earth. A seasonal cover of carbon-dioxide ice and snow is observed to advance and retreat over the poles during the Martian year. Scientists using radar data have found a record of the most recent Martian ice age recorded in the north polar ice cap. via NASA http://ift.tt/1sdb3bv

NGC 5078 and Friends

This sharp telescopic field of view holds two bright galaxies. Barred spiral NGC 5101 (top right) and nearly edge-on system NGC 5078 are separated on the sky by about 0.5 degrees or about the apparent width of a full moon. Found within the boundaries of the serpentine constellation Hydra, both are estimated to be around 90 million light-years away and similar in size to our own large Milky Way galaxy. In fact, if they both lie at the same distance their projected separation would be only 800,000 light-years or so. That's easily less than half the distance between the Milky Way and the Andromeda Galaxy. NGC 5078 is interacting with a smaller companion galaxy, cataloged as IC 879, seen just left of the larger galaxy's bright core. Even more distant background galaxies are scattered around the colorful field. Some are even visible right through the face-on disk of NGC 5101. But the prominent spiky stars are in the foreground, well within our own Milky Way. via NASA http://ift.tt/1WOiTos

NASA's OSIRIS-REx Spacecraft Prepared for Mission to an Asteroid

NASA's OSIRIS-REx spacecraft is revealed after its protective cover is removed inside the Payload Hazardous Servicing Facility at Kennedy Space Center, on May 21, 2016. OSIRIS-REx, targeted for a Sept. 8 launch, will be the first U.S. mission to sample an asteroid, retrieve at least two ounces of surface material and return it to Earth for study. via NASA http://ift.tt/1OWSkLu

Milky Way Over the Spanish Peaks

That's not lightning, and it did not strike between those mountains. The diagonal band is actually the central band of our Milky Way Galaxy, while the twin peaks are actually called the Spanish Peaks -- but located in Colorado, USA. Although each Spanish peak is composed of a slightly different type of rock, both are approximately 25 million years old. This serene yet spirited image composite was meticulously created by merging a series of images all taken from the same location on one night and early last month. In the first series of exposures, the background sky was built up, with great detail being revealed in the Milky Way dust lanes as well as the large colorful region surrounding the star Rho Ophiuchus just right of center. One sky image, though, was taken using a fogging filter so that brighter stars would appear more spread out and so more prominent. As a bonus, the planets Mars and Saturn are placed right above peaks and make an orange triangle with the bright star Antares. Later that night, after the moonrise, the Moon itself naturally illuminated the snow covered mountain tops. via NASA http://ift.tt/1TwOTI0

Fjord and Glacier in East-Central Greenland

On May 19, 2016, NASA's IceBridge, an airborne survey of polar ice, crossed Greenland to fly central glacier flowlines in the east-central region of the country. This photo captures the fjord of Violin Glacier, with Nord Glacier at the upper left corner. This is IceBridge's eighth spring campaign of science flights over Arctic sea and land. via NASA http://ift.tt/1s7jaq6

Inside a Daya Bay Antineutrino Detector

Why is there more matter than antimatter in the Universe? To better understand this facet of basic physics, energy departments in China and the USA led in the creation of the Daya Bay Reactor Neutrino Experiment. Located under thick rock about 50 kilometers northeast of Hong Kong, China, eight Daya Bay detectors monitor antineutrinos emitted by six nearby nuclear reactors. Featured here, a camera looks along one of the Daya Bay detectors, imaging photon sensors that pick up faint light emitted by antineutrinos interacting with fluids in the detector. Early results indicate an unexpectedly high rate of one type of antineutrino changing into another, a rate which, if confirmed, could imply the existence of a previously undetected type of neutrino as well as impact humanity's comprehension of fundamental particle reactions that occurred within the first few seconds of the Big Bang. via NASA http://ift.tt/25bsp6Q

Up and Over

Cassini orbited in Saturn's ring plane -- around the planet's equator -- for most of 2015. via NASA http://ift.tt/1WcJKuB

LL Orionis: When Cosmic Winds Collide

What created this great arc in space? This arcing, graceful structure is actually a bow shock about half a light-year across, created as the wind from young star LL Orionis collides with the Orion Nebula flow. Adrift in Orion's stellar nursery and still in its formative years, variable star LL Orionis produces a wind more energetic than the wind from our own middle-aged sun. As the fast stellar wind runs into slow moving gas a shock front is formed, analogous to the bow wave of a boat moving through water or a plane traveling at supersonic speed. The slower gas is flowing away from the Orion Nebula's hot central star cluster, the Trapezium, located off the lower right hand edge of the picture. In three dimensions, LL Ori's wrap-around shock front is shaped like a bowl that appears brightest when viewed along the "bottom" edge. The complex stellar nursery in Orion shows a myriad of similar fluid shapes associated with star formation, including the bow shock surrounding a faint star at the upper right. Part of a mosaic covering the Great Nebula in Orion, this composite color image was recorded in 1995 by the Hubble Space Telescope. via NASA http://ift.tt/25g4UwZ

Milky Way and Planets Near Opposition

In this early May night skyscape, a mountain road near Bursa, Turkey seems to lead toward bright planets Mars and Saturn and the center of our Milky Way Galaxy, a direction nearly opposite the Sun in planet Earth's sky. The brightest celestial beacon on the scene, Mars, reaches its opposition tonight and Saturn in early June. Both will remain nearly opposite the Sun, up all night and close to Earth for the coming weeks, so the time is right for good telescopic viewing. Mars and Saturn form the tight celestial triangle with red giant star Antares just right of the Milky Way's central bulge. But tonight the Moon is also at opposition. Easy to see near bright Mars and Saturn, the Full Moon's light will wash out the central Milky Way's fainter starlight though, even in dark mountain skies. via NASA http://ift.tt/257Pojj

3D Mercury Transit

On May 9, innermost planet Mercury crossed IN FRONT of the Sun. Though pictures project the event in only two dimensions, a remarkable three dimensional perspective on the transit is possible by free viewing this stereo pair. The images were made 23 minutes apart and rotated so that Mercury's position shifts horizontally between the two. As a result, Mercury's orbital motion produced an exaggerated parallax simulating binocular vision. Between the two exposures, the appropriately named planet's speedy 47.4 kilometer per second orbital velocity actually carried it over 65,000 kilometers. Taken first, the left image is intended for the right eye, so a cross-eyed view is needed to see Mercury's tiny silhouette suspended in the foreground. Try it. Merging the text below the images helps. via NASA http://ift.tt/20eTfaS

CubeSats Deployed From the International Space Station

CubeSats fly free after leaving the NanoRacks CubeSat Deployer on the International Space Station on May 17, 2016. Seen here are two Dove satellites. The satellites are part of a constellation designed, built and operated by Planet Labs Inc. to take images of Earth from space. via NASA http://ift.tt/27I2gi7

The Surface of Europa

An enhanced-color view, this image covers a 350 by 750 kilometer swath across the surface of Jupiter's tantalizing moon Europa. The close-up combines high-resolution image data with lower resolution color data from observations made in 1998 by the Galileo spacecraft. Smooth ice plains, long fractures, and jumbled blocks of chaos terrain are thought to hide a deep ocean of salty liquid water beneath. Though the ice-covered alien ocean world is outside the Solar System's habitable zone, new studies show the potential chemistry driving its oxygen and hydrogen production, a key indicator of the energy available for life, could produce amounts comparable in scale to planet Earth. Hydrogen would be generated by chemical reactions of the salty water in contact with the rocky ocean floor. Oxygen and other compounds that react with hydrogen would come from Europa's surface. There water ice molecules would be split apart by the intense flux of high-energy radiation from Jupiter and cycled into the Europan ocean from above. via NASA http://ift.tt/1U1G3kW

May 19, 2000, Early Morning Liftoff of Atlantis on STS-101 Mission

Flames from the solid rocket boosters lit up the clouds of smoke and steam trailing behind shuttle Atlantis on May 19, 2000, as it lifted off on mission STS-101. It was the shuttle program's third space station assembly flight, and first space flight for astronaut Jeff Williams, currently aboard the station as a member of the Expedition 47 crew. via NASA http://ift.tt/20aXPa5

Halo from Atacama

Influenced by the strong Pacific El Nino, cloudy skies have more often come to Chile's high Atacama Desert this season, despite its reputation as an astronomer's paradise. Located in one of the driest, darkest places on planet Earth, domes of the region's twin 6.5 meter Magellan telescopes of Carnegie Las Campanas Observatory were closed on May 13. Still, a first quarter Moon and bright stars shine through in this panoramic night skyscape, the lunar disk surrounded by a beautiful, bright halo. The angular radius of the halo is 22 degrees. Not determined by the brightness or phase of the Moon itself, the angle is set by the hexagonal geometry of atmospheric ice crystals that reflect and refract the moonlight. On that night, the brilliant star just inside the halo's radius was really planet Jupiter. The brightest star flanking the halo to the far left is Canopus, with Arcturus on the halo's right. via NASA http://ift.tt/1YBQOP5

Water Etchings in Western Mexico Sands

Expedition 47 Flight Engineer Tim Kopra of NASA posted this May 15, 2016 photograph to social media, writing, "Water etchings in western @Mexico sands. @Space_Station #Explore" via NASA http://ift.tt/1rTZdCW

The Orion Nebula in Visible and Infrared

The Great Nebula in Orion is a colorful place. Visible to the unaided eye, it appears as a small fuzzy patch in the constellation of Orion. Long exposure, multi-wavelength images like this, however, show the Orion Nebula to be a busy neighborhood of young stars, hot gas, and dark dust. This digital composite features not only three colors of visible light but four colors of infrared light taken by NASA's orbiting Spitzer Space Telescope as well. The power behind much of the Orion Nebula (M42) is the Trapezium - four of the brightest stars in the nebula. Many of the filamentary structures visible are actually shock waves - fronts where fast moving material encounters slow moving gas. The Orion Nebula spans about 40 light years and is located about 1500 light years away in the same spiral arm of our Galaxy as the Sun. via NASA http://ift.tt/201tJWu

Stargazing From the International Space Station

Astronauts aboard the International Space Station (ISS) see the world at night on every orbit — that’s 16 times each crew day. An astronaut took this broad, short-lens photograph of Earth’s night lights while looking out over the remote reaches of the central equatorial Pacific Ocean. via NASA http://ift.tt/1rRGKHd

Clouds of the Carina Nebula

What forms lurk in the mists of the Carina Nebula? The dark ominous figures are actually molecular clouds, knots of molecular gas and dust so thick they have become opaque. In comparison, however, these clouds are typically much less dense than Earth's atmosphere. Featured here is a detailed image of the core of the Carina Nebula, a part where both dark and colorful clouds of gas and dust are particularly prominent. The image was captured last month from Siding Spring Observatory in Australia. Although the nebula is predominantly composed of hydrogen gas -- here colored green, the image was assigned colors so that light emitted by trace amounts of sulfur and oxygen appear red and blue, respectively. The entire Carina Nebula, cataloged as NGC 3372, spans over 300 light years and lies about 7,500 light-years away in the constellation of Carina. Eta Carinae, the most energetic star in the nebula, was one of the brightest stars in the sky in the 1830s, but then faded dramatically. via NASA http://ift.tt/1ThxMNQ

Celebrating Ten Years of NASA's Consolidated Space Communications Program

This photograph shows NASA’s newest Deep Space Network antenna, Deep Space Station 35 (DSS-35) in Canberra, Australia. The Deep Space Network is managed by the Space Communications and Navigation (SCaN) program office, created on May 16, 2006. via NASA http://ift.tt/27setrc

Milky Way Over Quiver Tree Forest

In front of a famous background of stars and galaxies lies some of Earth's more unusual trees. Known as quiver trees, they are actually succulent aloe plants that can grow to tree-like proportions. The quiver tree name is derived from the historical usefulness of their hollowed branches as dart holders. Occurring primarily in southern Africa, the trees pictured in the above 16-exposure composite are in Quiver Tree Forest located in southern Namibia. Some of the tallest quiver trees in the park are estimated to be about 300 years old. Behind the trees is light from the small town of Keetmanshoop, Namibia. Far in the distance, arching across the background, is the majestic central band of our Milky Way Galaxy. Even further in the distance, visible on the image left, are the Large and Small Magellanic Clouds, smaller satellite galaxies of the Milky Way that are prominent in the skies of Earth's southern hemisphere. via NASA http://ift.tt/22aLpAJ

Falcon 9 and Milky Way

On May 6, the after midnight launch of a SpaceX Falcon 9 rocket lit up dark skies over Merritt Island, planet Earth. Its second stage bound for Earth orbit, the rocket's arc seems to be on course for the center of the Milky Way in this pleasing composite image looking toward the southeast. Two consecutive exposures made with camera fixed to a tripod were combined to follow rocket and home galaxy. A 3 minute long exposure at low sensitivity allowed the rocket's first stage burn to trace the bright orange arc and a 30 second exposure at high sensitivity captured the stars and the faint Milky Way. Bright orange Mars dominates the starry sky at the upper right. A few minutes later, booster engines were restarted and the Falcon 9's first stage headed for a landing on the autonomous spaceport drone ship Of Course I Still Love You, patiently waiting in the Atlantic 400 miles east of the Cape Canaveral launch site. via NASA http://ift.tt/27mf1yT

ISS and Mercury Too

Transits of Mercury are relatively rare. Monday's leisurely 7.5 hour long event was only the 2nd of 14 Mercury transits in the 21st century. If you're willing to travel, transits of the International Space Station can be more frequent though, and much quicker. This sharp video frame composite was taken from a well-chosen location in Philadelphia, USA. It follows the space station, moving from upper right to lower left, as it crossed the Sun's disk in 0.6 seconds. Mercury too is included as the small, round, almost stationary silhouette just below center. In apparent size, the International Space Station looms larger from low Earth orbit, about 450 kilometers from Philadelphia. Mercury was about 84 million kilometers away. (Editor's note: The stunning video includes another double transit, Mercury and a Pilatus PC12 aircraft. Even quicker than the ISS to cross the Sun, the aircraft was about 1 kilometer away.) via NASA http://ift.tt/1rJM3bK

Hubble Spies a Spiral Snowflake

Together with irregular galaxies, spiral galaxies make up approximately 60 percent of the galaxies in the local universe. However, despite their prevalence, each spiral galaxy is unique — like snowflakes, no two are alike. This is demonstrated by the striking face-on spiral galaxy NGC 6814. via NASA http://ift.tt/1TKk7dX

A Transit of Mercury

On May 9, the diminutive disk of Mercury spent about seven and a half hours crossing in front of the Sun as viewed from the general vicinity of Earth. It was the second of 14 transits of the Solar System's innermost planet in the 21st century. Captured from Fulham, London, England, planet Earth the tiny silhouette shares the enormous solar disk with prominences, filaments, and active regions in this sharp image. But Mercury's round disk (left of center) appears to be the only dark spot, despite the planet-sized sunspots scattered across the Sun. Made with an H-alpha filter that narrowly transmits the red light from hydrogen atoms, the image emphasizes the chromosphere, stretching above the photosphere or normally visible solar surface. In H-alpha pictures of the chromosphere, normally dark sunspot regions are dominated by bright splotches called plages. via NASA http://ift.tt/1TcE1Bd

NASA's IceBridge Flies Over the Front of a Greenland Glacier

Operation IceBridge, NASA's airborne survey of polar ice, has returned from the Umanaq B mission along Greenland's western coast. This top-down view from a NOAA P-3 aircraft shows the calving front of Sermeq Kujatdleq glacier. The Naircraft's #2 lower engine nacelle and left main landing gear fairing is in the foreground at top. via NASA http://ift.tt/220Oins

Full of Science, Dragon Spacecraft Undocks for Return to Earth

ESA astronaut Tim Peake photographed the SpaceX Dragon cargo craft as it undocked from the International Space Station on May 11, 2016. Scheduled to splashdown in the Pacific Ocean at 2:55 p.m. EDT, the spacecraft will return the final batch of human research samples from former NASA astronaut Scott Kelly’s historic one-year mission. via NASA http://ift.tt/1XlmJov

Saturn and Mars visit Milky Way Star Clouds

Planets, stars, nebulas and a galaxy -- this impressive image has them all. Closest to home are the two planets Mars (right) and Saturn (center), visible as the two bright orange spots in the upper half of the featured image. On the central right are the colorful Rho Ophiuchus star clouds featuring the bright orange star Antares lined up below Mars. These interstellar clouds contain both red emission nebulas and blue reflection nebulas. At the top right of the image is the Blue Horsehead reflection nebula. On the lower left are many dark absorption nebulas that extend from the central band of our Milky Way Galaxy. The featured deep composite was composed of multiple deep exposures taken last month from Brazil. Although you need a telescope to see the nebulosities, Saturn and Mars will remain visible to the unaided eye this month toward the east, just after sunset. via NASA http://ift.tt/1Xj749i

Smoke From Canadian Wildfires Trapped in Clouds

NASA's Aqua satellite captured this image of the clouds over Canada on May 9, 2016. Entwined within the clouds is the smoke billowing up from the wildfires that are currently burning across a large expanse of the country. via NASA http://ift.tt/1WniUAg

Mercury Solar Transit

The planet Mercury is seen in silhouette, lower third of image, as it transits across the face of the sun Monday, May 9, 2016, as viewed from Boyertown, Pennsylvania. Mercury passes between Earth and the sun only about 13 times a century, with the previous transit taking place in 2006. via NASA http://ift.tt/1T6P1TE

Mercurys Transit: An Unusual Spot on the Sun

What's that dot on the Sun? If you look closely, it is almost perfectly round. The dot is the result of an unusual type of solar eclipse that occurred in 2006. Usually it is the Earth's Moon that eclipses the Sun. This time, the planet Mercury took a turn. Like the approach to New Moon before a solar eclipse, the phase of Mercury became a continually thinner crescent as the planet progressed toward an alignment with the Sun. Eventually the phase of Mercury dropped to zero and the dark spot of Mercury crossed our parent star. The situation could technically be labeled a Mercurian annular eclipse with an extraordinarily large ring of fire. From above the cratered planes of the night side of Mercury, the Earth appeared in its fullest phase. Hours later, as Mercury continued in its orbit, a slight crescent phase appeared again. This was ten years ago -- the next Mercurian solar eclipse will occur tomorrow. via NASA http://ift.tt/1QVAv9L

Three Worlds for TRAPPIST 1

Three new found worlds orbit the ultracool dwarf star TRAPPIST-1, a mere 40 light-years away. Their transits were first detected by the Belgian robotic TRAnsiting Planets and Planetesimals Small Telescope, TRAPPIST, at ESO's La Silla Observatory in Chile. The newly discovered exoplanets are all similar in size to Earth. Because they orbit very close to their faint, tiny star they could also have regions where surface temperatures allow for the presence of liquid water, a key ingredient for life. Their tantalizing proximity to Earth makes them prime candidates for future telescopic explorations of the atmospheres of these potentially habitable planets. All three worlds appear in this artist's vision, an imagined scene near the horizon of the system's outermost planet. Of course, the inner planet is transiting the dim, red, nearly Jupiter-sized parent star. via NASA http://ift.tt/1TunIgc

NGC 7023: The Iris Nebula

These cosmic clouds have blossomed 1,300 light-years away, in the fertile starfields of the constellation Cepheus. Called the Iris Nebula, NGC 7023 is not the only nebula to evoke the imagery of flowers, though. Still, this deep telescopic image shows off the Iris Nebula's range of colors and symmetries, embedded in surrounding fields of interstellar dust. Within the Iris itself, dusty nebular material surrounds a hot, young star. The dominant color of the brighter reflection nebula is blue, characteristic of dust grains reflecting starlight. Central filaments of the reflection nebula glow with a faint reddish photoluminesence as some dust grains effectively convert the star's invisible ultraviolet radiation to visible red light. Infrared observations indicate that this nebula contains complex carbon molecules known as PAHs. The pretty blue petals of the Iris Nebula span about six light-years. The colorful field-of-view stretches almost five Full Moons across the sky. via NASA http://ift.tt/1YcJWY8

Hubble Spies the Barred Spiral Galaxy NGC 4394

Shown in this Hubble Space Telescope image, NGC 4394 is the archetypal barred spiral galaxy, with bright spiral arms emerging from the ends of a bar that cuts through the galaxy’s central bulge. These arms are peppered with young blue stars, dark filaments of cosmic dust, and bright, fuzzy regions of active star formation. via NASA http://ift.tt/1rZSvvv

The SONG and the Hunter

Near first quarter, the Moon in March lights this snowy, rugged landscape, a view across the top of Tenerife toward La Palma in the Canary Islands Spanish archipelago. The large Teide volcano, the highest point in Spain, looms over the horizon. Shining above are familiar bright stars of Orion, the Hunter. Adding to the dreamlike scene is the 1 meter diameter prototype telescope of the global network project called the Stellar Observations Network Group or SONG. The SONG's fully robotic observatory was captured during the 30 second exposure while the observatory dome, with slit open, was rotated across the field of view. via NASA http://ift.tt/1Yax1pL

May 5, 1961, Alan Shepard in Spacesuit Before Mercury Launch

Astronaut Alan B. Shepard Jr., in his silver pressure suit with the helmet visor closed, prepares for his Mercury Redstone 3 launch on May 5, 1961. Shepard's Freedom 7 Mercury capsule lifted off at 9:34 a.m. and flew a suborbital trajectory lasting 15 minutes and 22 seconds. He became the first American to fly into space. via NASA http://ift.tt/24ukJja

A Mercury Transit Sequence

This coming Monday, Mercury will cross the face of the Sun, as seen from Earth. Called a transit, the last time this happened was in 2006. Because the plane of Mercury's orbit is not exactly coincident with the plane of Earth's orbit, Mercury usually appears to pass over or under the Sun. The above time-lapse sequence, superimposed on a single frame, was taken from a balcony in Belgium shows the entire transit of 2003 May 7. The solar crossing lasted over five hours, so that the above 23 images were taken roughly 15 minutes apart. The north pole of the Sun, the Earth's orbit, and Mercury's orbit, although all different, all occur in directions slightly above the left of the image. Near the center and on the far right, sunspots are visible. After Monday, the next transit of Mercury will occur in 2019. via NASA http://ift.tt/1rUadRe

Many Fantastic Colors

The Nili Fossae region, located on the northwest rim of Isidis impact basin, is one of the most colorful regions of Mars. This region is ancient and has had a complicated geologic history, leading to interesting structures like layered bedrock, as well as other compositions. via NASA http://ift.tt/1W7TdTm

Aurora over Sweden

It was bright and green and stretched across the sky. This striking aurora display was captured last month just outside of Östersund, Sweden. Six photographic fields were merged to create the featured panorama spanning almost 180 degrees. Particularly striking aspects of this aurora include its sweeping arc-like shape and its stark definition. Lake Storsjön is seen in the foreground, while several familiar constellations and the star Polaris are visible through the aurora, far in the background. Coincidently, the aurora appears to avoid the Moon visible on the lower left. The aurora appeared a day after a large hole opened in the Sun's corona allowing particularly energetic particles to flow out into the Solar System. The green color of the aurora is caused by oxygen atoms recombining with ambient electrons high in the Earth's atmosphere. via NASA http://ift.tt/23lOPPW

Space Station Flyover of Morocco

Expedition 47 Flight Engineer Jeff Williams of NASA captured this detailed photograph from the International Space Station during a daytime flyover of Morocco on May 2, 2016. Williams shared the image to social media and asked, "Reptile scales, or incredible and rugged geology in Morocco?" via NASA http://ift.tt/1SWtCto

Crossing Mars

Where is NASA's rover Curiosity going on Mars? Its geographical goals are on the slopes of Mount Sharp, whose peak is seen in the background on the right. A key scientific goal, however, remains to better assess when and where conditions on Mars were once suitable for life, in particular microbial life. To further this goal, Curiosity was directed to cross the rugged terrain of Nautkluft Plateau, visible in the featured image on the foreground left. Curiosity is crossing toward smoother uphill sites with rocks containing hematite and sulfates, sites that could give the rolling rover new clues on how long this part of Mars was wet -- and hence more favorable for life -- before drying out. Of recent concern, however, is Curiosity's aluminum wheels, which are showing increasing signs of wear. Although already fulfilling the goals of its two year study, Curiosity's mission has been extended as it continues to uncover valuable information about the extraordinary past of Mars, the next planet out from the Sun from Earth. via NASA http://ift.tt/1Z2PEfl

The Dew Drop of Saturn

The water-world Enceladus appears here to sit atop Saturn's rings like a drop of dew upon a leaf. Even though it appears like a tiny drop before the might of the giant Saturn, Enceladus reminds us that even small worlds hold mysteries and wonders to be explored. via NASA http://ift.tt/1SGdNb7

Contemplating the Sun

Have you contemplated your home star recently? Featured here, a Sun partially eclipsed on the top left by the Moon is also seen eclipsed by earthlings contemplating the eclipse below. The spectacular menagerie of silhouettes was taken in 2012 from the Glen Canyon National Recreation Area near Page, Arizona, USA, where park rangers and astronomers expounded on the unusual event to interested gatherers. Also faintly visible on the Sun's disk, just to the lower right of the dark Moon's disk, is a group of sunspots. Although a partial solar eclipse by the Moon is indeed a good chance to contemplate the Sun, a great chance -- and one that is significantly more rare -- will occur next week when the Sun undergoes a partial eclipse by the planet Mercury. via NASA http://ift.tt/26H6BBR

Moon over Makemake

Makemake, second brightest dwarf planet of the Kuiper belt, has a moon. Nicknamed MK2, Makemake's moon reflects sunlight with a charcoal-dark surface, about 1,300 times fainter than its parent body. Still, it was spotted in Hubble Space Telescope observations intended to search for faint companions with the same technique used to find the small satellites of Pluto. Just as for Pluto and its satellites, further observations of Makemake and orbiting moon will measure the system's mass and density and allow a broader understanding of the distant worlds. About 160 kilometers (100 miles) across compared to Makemake's 1,400 kilometer diameter, MK2's relative size and contrast are shown in this artist's vision. An imagined scene of an unexplored frontier of the Solar System, it looks back from a spacecraft's vantage as the dim Sun shines along the Milky Way. Of course, the Sun is over 50 times farther from Makemake than it is from planet Earth. via NASA http://ift.tt/26DRj0x