Overview of MESSENGER Spacecraft's Impact Region on Mercury

On April 30th, this region of Mercury's surface will have a new crater! Traveling at 3.91 kilometers per second (over 8,700 miles per hour), the MESSENGER spacecraft will collide with Mercury's surface, creating a crater estimated to be 16 meters (52 feet) in diameter. via NASA http://ift.tt/1IrJm3c


April 29, 1990, Shuttle Discovery Lands Following Hubble Deployment Mission

On April 29, 1990, the Space Shuttle Discovery approaches for landing on a concrete runway at Edwards Air Force Base to complete a highly successful five-day mission during which the Hubble Space Telescope was released into orbit. via NASA http://ift.tt/1FxFQn9


Astronaut Scott Kelly Speaks at Shuttle Enterprise Dedication Ceremony

NASA astronaut Scott Kelly delivers remarks from onboard the International Space Station during the Space Shuttle Enterprise dedication ceremony Monday, April 27, 2015, at the Intrepid Sea, Air & Space Museum in New York City. Enterprise was dedicated to the fallen crews who gave their lives in pursuit of space exploration. via NASA http://ift.tt/1JOwG4D

Space Station over Lunar Terminator

What's that in front of the Moon? It's the International Space Station. Using precise timing, the Earth-orbiting space platform was photographed in front of a partially lit Moon last year. The featured image was taken from Madrid, Spain with an exposure time of only 1/1000 of a second. In contrast, the duration of the transit of the ISS across the entire Moon was about half a second. The sun-glinting station can be seen just to the dark side of the day / night line known as the terminator. Numerous circular craters are visible on the distant Moon, as well as comparatively rough, light colored terrain known as highlands, and relatively smooth, dark colored areas known as maria. On-line tools can tell you when the International Space Station will be visible from your area. via NASA http://ift.tt/1KmcckE


Unmasking the Secrets of Mercury

To learn more about the minerals and surface processes on Mercury, instruments aboard NASA's MESSENGER spacecraft have been collecting surface measurements since MESSENGER entered Mercury orbit on March 17, 2011. via NASA http://ift.tt/1zeU37k

Planetary Nebula Mz3: The Ant Nebula

Why isn't this ant a big sphere? Planetary nebula Mz3 is being cast off by a star similar to our Sun that is, surely, round. Why then would the gas that is streaming away create an ant-shaped nebula that is distinctly not round? Clues might include the high 1000-kilometer per second speed of the expelled gas, the light-year long length of the structure, and the magnetism of the star visible above at the nebula's center. One possible answer is that Mz3 is hiding a second, dimmer star that orbits close in to the bright star. A competing hypothesis holds that the central star's own spin and magnetic field are channeling the gas. Since the central star appears to be so similar to our own Sun, astronomers hope that increased understanding of the history of this giant space ant can provide useful insight into the likely future of our own Sun and Earth. via NASA http://ift.tt/1E7nJCe


Cluster and Starforming Region Westerlund 2

Located 20,000 light-years away in the constellation Carina, the young cluster and starforming region Westerlund 2 fills this cosmic scene. Captured with Hubble's cameras in near-infrared and visible light, the stunning image is a celebration of the 25th anniversary of the launch of the Hubble Space Telescope on April 24, 1990. The cluster's dense concentration of luminous, massive stars is about 10 light-years across. Strong winds and radiation from those massive young stars have sculpted and shaped the region's gas and dust, into starforming pillars that point back to the central cluster. Red dots surrounding the bright stars are the cluster's faint newborn stars, still within their natal gas and dust cocoons. But brighter blue stars scattered around are likely not in the Westerlund 2 cluster and instead lie in the foreground of the Hubble anniversary field of view. via NASA http://ift.tt/1aZXkM1


Blue Tears and the Milky Way

Lapping at rocks along the shore of the Island of Nangan, Taiwan, planet Earth, waves are infused with a subtle blue light in this sea and night skyscape. Composed of a series of long exposures made on April 16 the image captures the faint glow from Noctiluca scintillans. Also known as sea sparkles or blue tears, the marine plankton's bioluminescence is stimulated by wave motion. City lights along the coast of mainland China shine beneath low clouds in the west but stars and the faint Milky Way still fill the night above. Over the horizon the galaxy's central bulge and dark rifts seem to echo the rocks and luminous waves. via NASA http://ift.tt/1ExrgNs


April 25, 1990, Deployment of the Hubble Space Telescope

In this April 25, 1990, photograph taken by the crew of the STS-31 space shuttle mission, the Hubble Space Telescope is suspended above shuttle Discovery's cargo bay some 332 nautical miles above Earth. via NASA http://ift.tt/1DHC056

Meteor in the Milky Way

Earth's April showers include the Lyrid Meteor Shower, observed for more than 2,000 years when the planet makes its annual passage through the dust stream of long-period Comet Thatcher. A grain of that comet's dust, moving 48 kilometers per second at an altitude of 100 kilometers or so, is swept up in this night sky view from the early hours of April 21. Flashing toward the southeastern horizon, the meteor's brilliant streak crosses the central region of the rising Milky Way. Its trail points back toward the shower's radiant in the constellation Lyra, high in the northern springtime sky and off the top of the frame. The yellowish hue of giant star Antares shines to the right of the Milky Way's bulge. Higher still is bright planet Saturn, near the right edge. Seen from Istra, Croatia, the Lyrid meteor's greenish glow reflects in the waters of the Adriatic Sea. via NASA http://ift.tt/1HoENaF


Celestial Fireworks

The brilliant tapestry of young stars flaring to life resemble a glittering fireworks display in the 25th anniversary NASA Hubble Space Telescope image, released to commemorate a quarter century of exploring the solar system and beyond since its launch on April 24, 1990. via NASA http://ift.tt/1HqPKbC

Colorful Star Clouds in Cygnus

Stars can form in colorful surroundings. Featured here is a star forming region rich in glowing gas and dark dust toward the constellation of the Swan (Cygnus), near the bright star Sadr. This region, which spans about 50 light years, is part of the Gamma Cygni nebula which lies about 1,800 light years distant. Toward the right of the image is Barnard 344, a dark and twisted dust cloud rich in cool molecular gas. A dramatic wall of dust and red-glowing hydrogen gas forms a line down the picture center. While the glowing red gas is indicative of small emission nebulas, the blue tinted areas are reflection nebulas -- starlight reflecting from usually dark dust grains. The Gamma Cygni nebula will likely not last the next billion years, as most of the bright young stars will explode, most of the dust will be destroyed, and most of the gas will drift away. via NASA http://ift.tt/1GgOTas


NASA Tail Technology Could Someday Reduce Airplane Fuel Use

In this photo taken from a chase plane, the Boeing ecoDemonstrator 757 flight test airplane --with NASA's Active Flow Control technology installed on the tail -- makes a final approach to King County Boeing Field in Seattle, Washington. via NASA http://ift.tt/1OGdlnA


A Sky View of Earth From Suomi NPP

This 15,000-by-15,000-pixel image of southern Africa and the surrounding oceans took six orbits of the Suomi NPP spacecraft to compile. via NASA http://ift.tt/1aPhuIp

Total Solar Eclipse over Svalbard

Going, going, gone. That was the feeling in Svalbard, Norway last month during a total eclipse of the Sun by the Moon. In the featured image, the eclipse was captured every three minutes and then digitally merged with a foreground frame taken from the same location. Visible in the foreground are numerous gawking eclipse seekers, some deploying pretty sophisticated cameras. As the Moon and Sun moved together across the sky -- nearly horizontally from this far north -- an increasing fraction of the Sun appears covered by the Moon. In the central frame, the Moon's complete blockage of the disk of the Sun makes the immediate surroundings appear like night during the day. The exception is the Moon itself, which now appears surrounded by the expansive corona of the Sun. Of course, about 2.5 minutes later, the surface of the Sun began to reappear. The next total eclipse of the Sun will occur in 2016 March and be visible from Southeast Asia. via NASA http://ift.tt/1Q80TAK


Reflecting on a Spacecraft Arrival

NASA astronaut Scott Kelly, currently on a one-year mission on the International Space Station, posted this image of the successful capture of the SpaceX Dragon spacecraft with the space station's robotic arm. via NASA http://ift.tt/1Jnghnr

Ring Galaxy AM 0644 741 from Hubble

How could a galaxy become shaped like a ring? The rim of the blue galaxy pictured on the right is an immense ring-like structure 150,000 light years in diameter composed of newly formed, extremely bright, massive stars. That galaxy, AM 0644-741, is known as a ring galaxy and was caused by an immense galaxy collision. When galaxies collide, they pass through each other -- their individual stars rarely come into contact. The ring-like shape is the result of the gravitational disruption caused by an entire small intruder galaxy passing through a large one. When this happens, interstellar gas and dust become condensed, causing a wave of star formation to move out from the impact point like a ripple across the surface of a pond. The intruder galaxy is just outside of the frame taken by the Hubble Space Telescope. This featured image was taken to commemorate the anniversary of Hubble's launch in 1990. Ring galaxy AM 0644-741 lies about 300 million light years away. via NASA http://ift.tt/1OWthnF


The Great Crater Hokusai

One of the largest young craters on Mercury, 114 kilometer (71 mile) diameter Hokusai crater's bright rays are known to extend across much of the planet. But this mosaic of oblique views focuses on Hokusai close up, its sunlit central peaks, terraced crater walls, and frozen sea of impact melt on the crater's floor. The images were captured by the MESSENGER spacecraft. The first to orbit Mercury, since 2011 MESSENGER has conducted scientific explorations, including extensive imaging of the Solar System's innermost planet. Now running out of propellant and unable to counter orbital perturbations caused by the Sun's gravity, MESSENGER is predicted to impact the surface of Mercury on April 30. via NASA http://ift.tt/1JS7via


M46 Plus Two

Galactic or open star clusters are young. These swarms of stars are born together near the plane of the Milky Way, but their numbers steadily dwindle as cluster members are ejected by galactic tides and gravitational interactions. In fact, this bright open cluster, known as M46, is around 300 million years young. It still contains a few hundred stars within a span of 30 light-years or so. Located about 5,000 light-years away toward the constellation Puppis, M46 also seems to contain contradictions to its youthful status. In this pretty starscape, the colorful, circular patch above and right of the center of M46 is the planetary nebula NGC 2438. Fainter still, a second planetary nebula, PK231+4.1, is identified by the box at the right and enlarged in the inset. Planetary nebulae are a brief, final phase in the life of a sun-like star a billion years old or more, whose central reservoir of hydrogen fuel has been exhausted. NGC 2438 is estimated to be only 3,000 light-years distant, though, and moves at a different speed than M46 cluster members. Along with its fainter cohort, planetary nebula NGC 2438 is likely only by chance appearing near our line-of-sight to the young stars of M46. via NASA http://ift.tt/1CUGJ2I

White Dwarf May Have Shredded Passing Planet

In this Chandra image of ngc6388, researchers have found evidence that a white dwarf star may have ripped apart a planet as it came too close. When a star reaches its white dwarf stage, nearly all of the material from the star is packed inside a radius one hundredth that of the original star. The destruction of a planet may sound like the stuff of science fiction, but a team of astronomers has found evidence that this may have happened in an ancient cluster of stars at the edge of the Milky Way galaxy. Using several telescopes, including NASA’s Chandra X-ray Observatory, researchers have found evidence that a white dwarf star – the dense core of a star like the Sun that has run out of nuclear fuel – may have ripped apart a planet as it came too close. More information. Image Credit: NASA via NASA http://ift.tt/1CXW0jf


White Dwarf May Have Shredded Passing Planet

In this Chandra image of ngc6388, researchers have found evidence that a white dwarf star may have ripped apart a planet as it came too close. When a star reaches its white dwarf stage, nearly all of the material from the star is packed inside a radius one hundredth that of the original star. The destruction of a planet may sound like the stuff of science fiction, but a team of astronomers has found evidence that this may have happened in an ancient cluster of stars at the edge of the Milky Way galaxy. Using several telescopes, including NASA’s Chandra X-ray Observatory, researchers have found evidence that a white dwarf star – the dense core of a star like the Sun that has run out of nuclear fuel – may have ripped apart a planet as it came too close. More information. Image Credit: NASA via NASA http://ift.tt/1cCAvPO

One-Armed Spiral Galaxy NGC 4725

While most spiral galaxies, including our own Milky Way, have two or more spiral arms, NGC 4725 has only one. In this sharp color composite image, the solo spira mirabilis seems to wind from a prominent ring of bluish, newborn star clusters and red tinted star forming regions. The odd galaxy also sports obscuring dust lanes a yellowish central bar structure composed of an older population of stars. NGC 4725 is over 100 thousand light-years across and lies 41 million light-years away in the well-groomed constellation Coma Berenices. Computer simulations of the formation of single spiral arms suggest that they can be either leading or trailing arms with respect to a galaxy's overall rotation. Also included in the frame, sporting a noticably more traditional spiral galaxy look, is a more distant background galaxy. via NASA http://ift.tt/1J5wFJ7


Mystic Mountain Dust Pillars

It's stars versus dust in the Carina Nebula and the stars are winning. More precisely, the energetic light and winds from massive newly formed stars are evaporating and dispersing the dusty stellar nurseries in which they formed. Located in the Carina Nebula and known informally as Mystic Mountain, these pillar's appearance is dominated by the dark dust even though it is composed mostly of clear hydrogen gas. Dust pillars such as these are actually much thinner than air and only appear as mountains due to relatively small amounts of opaque interstellar dust. About 7,500 light-years distant, the featured image was taken with the Hubble Space Telescope, digitally reprocessed by an industrious amateur, and highlights an interior region of Carina which spans about three light years. Within a few million years, the stars will likely win out completely and the entire dust mountain will be destroyed. via NASA http://ift.tt/1EDpfOa


Honoring Jackie Robinson

"Honoring #JackieRobinson today! #42" wrote NASA astronaut Terry Virts, wearing a replica Jackie Robinson jersey on orbit in the cupola of the International Space Station. April 15, which was baseball’s opening day in 1947, has now come to commemorate Jackie Robinson’s memorable career and his place in history as the first black major league baseball player in the modern era. He made history with the Brooklyn Dodgers (now the Los Angeles Dodgers) and he was inducted to the Baseball Hall of Fame in 1962. Image Credit: NASA via NASA http://ift.tt/1DiQYl5


SpaceX Launches NASA Cargo and Research To International Space Station

A SpaceX Falcon 9 rocket lifts off from Space Launch Complex 40 at Cape Canaveral Air Force Station carrying the Dragon resupply spacecraft on the sixth commercial resupply services mission to the International Space Station. Liftoff was at 4:10 p.m. EDT, Tuesday, April 14. Research that will help prepare NASA astronauts and robotic explorers for future missions to Mars is among the two tons of cargo on its way to the International Space Station aboard Dragon. The mission is the company's sixth cargo delivery flight to the station through NASA’s Commercial Resupply Services contract. Dragon's cargo will support approximately 40 of the more than 250 science and research investigations that will be performed during Expeditions 43 and 44, including numerous human research investigations for NASA astronaut Scott Kelly's one-year mission in space. Image Credit: NASA/Kim Shiflett via NASA http://ift.tt/1PJqGyI

Solar Arrays on the International Space Station

Expedition 43 Flight Engineer Samantha Cristoforetti of the European Space Agency (ESA) photographed the giant solar arrays on the International Space Station on Feb. 12, 2015. The space station's solar arrays contain a total of 262,400 solar cells and cover an area of about 27,000 square feet (2,500 square meters) -- more than half the area of a football field. A solar array's wingspan of 240 feet (73 meters) is longer than a Boeing 777's wingspan, which is 212 feet (65 meters). Altogether, the four sets of arrays can generate 84 to 120 kilowatts of electricity -- enough to provide power to more than 40 homes. The solar arrays produce more power than the station needs at one time for station systems and experiments. When the station is in sunlight, about 60 percent of the electricity that the solar arrays generate is used to charge the station's batteries. At times, some or all of the solar arrays are in the shadow of Earth or the shadow of part of the station. This means that those arrays are not collecting sunlight. The batteries power the station when it is not in the sun. Image Credit: ESA/NASA via NASA http://ift.tt/1FFwnWl

Milky Way over Erupting Volcano

The view was worth the trip. Battling high winds, cold temperatures, and low oxygen, the trek to near the top of the volcano Santa Maria in Guatemala -- while carrying sensitive camera equipment -- was lonely and difficult. Once set up, though, the camera captured this breathtaking vista during the early morning hours of February 28. Visible on the ground are six volcanoes of the Central America Volcanic Arc, including Fuego, the Volcano of Fire, which is seen erupting in the distance. Visible in the sky, in separate exposures taken a few minutes later, are many stars much further in the distance, as well as the central band of our Milky Way Galaxy situated horizontally overhead. via NASA http://ift.tt/1I8rbwY


Sentinels of the Arctic

Who guards the north? Judging from the above photograph, possibly giant trees covered in snow and ice. The featured picture was taken a few winters ago in Finnish Lapland where weather can include sub-freezing temperatures and driving snow. Surreal landscapes sometimes result, where common trees become cloaked in white and so appear, to some, as watchful aliens. Far in the distance, behind this uncommon Earthly vista, is a more common sight -- a Belt of Venus that divided a darkened from sunlit sky as the Sun rose behind the photographer. Of course, in the spring, the trees thaw and Lapland looks much different. via NASA http://ift.tt/1FMlJQ9


Venus in the West

In the coming days, Venus shines near the western horizon at sunset. To find Earth's sister planet in twilight skies just look for the brilliant evening star. Tonight very close to the Pleiades star cluster, Venus dominates this springtime night skyscape taken only a few days ago near the town of Lich in central Germany. Also known as the Seven Sisters, the stars of the compact Pleiades cluster appear above Venus in this picture. The budding tree branches to its left frame bright star Aldebaran, the eye of Taurus the Bull, and the V-shaped Hyades star cluster. via NASA http://ift.tt/1I1ozBb


NGC 2903: A Missing Jewel in Leo

Barred spiral galaxy NGC 2903 is only some 20 million light-years distant. Popular among amateur astronomers, it shines in the northern spring constellation Leo, near the top of the lion's head. That part of the constellation is sometimes seen as a reversed question mark or sickle. One of the brighter galaxies visible from the northern hemisphere, NGC 2903 is surprisingly missing from Charles Messier's catalog of lustrous celestial sights. This colorful image from a small ground-based telescope shows off the galaxy's gorgeous spiral arms traced by young, blue star clusters and pinkish star forming regions. Included are intriguing details of NGC 2903's bright core, a remarkable mix of old and young clusters with immense dust and gas clouds. In fact, NGC 2903 exhibits an exceptional rate of star formation activity near its center, also bright in radio, infrared, ultraviolet, and x-ray bands. Just a little smaller than our own Milky Way, NGC 2903 is about 80,000 light-years across. via NASA http://ift.tt/1HXGmZK


A Golden Gate Eclipse

Shadows play on the water and in the sky in this panoramic view of the April 4 total lunar eclipse over San Francisco's Golden Gate Bridge. Just within planet Earth's shadow the Full Moon's disk is still easy to spot at its brief total phase. The urban night skyscape was composed to cover the wide range of brightness visible to the eye. The shortest total lunar eclipse of the century, this eclipse was also the third in a string of four consecutive total lunar eclipses, a series known as a tetrad. Coming in nearly six month intervals, the previous two were last April 15 and October 8. The next and final eclipse in the tetrad will be on September 28. This 2014-2015 tetrad is one of 8 total lunar eclipse tetrads in the 21st century. via NASA http://ift.tt/1GrcuHY


The Mercury Astronauts

On April 9, 1959, NASA's first administrator, Dr. Keith Glennan, announced the names of the agency's first group of astronauts at a news conference in Washington, D.C. Now known as the "Original Seven," they included three Naval aviators, M. Scott Carpenter, Walter M. Schirra Jr., and Alan B. Shepard Jr.; three Air Force pilots, L. Gordon Cooper Jr., Virgil I. (Gus) Grissom, and Donald K. (Deke) Slayton; along with Marine Corps aviator John H. Glenn Jr. This group photo of the original Mercury astronauts was taken in June 1963 at the Manned Spacecraft Center (MSC), now Johnson Space Center, in Houston, Texas. The astronauts are, left-to-right: Cooper, Schirra, Shepard, Grissom, Glenn, Slayton and Carpenter. Project Mercury became NASA's first major undertaking. The objectives of the program were to place a human-rated spacecraft into orbit around Earth, observe the astronaut's performance in such conditions and safely recover the astronaut and the spacecraft. The Mercury flights proved that humans could live and work in space, and paved the way for the Gemini and Apollo programs as well as for all further human spaceflight. Image Credit: NASA via NASA http://ift.tt/1NWFJ4z

Full Moon in Earth's Shadow

Last week the Full Moon was completely immersed in Earth's dark umbral shadow, just briefly though. The total phase of the April 4, 2015 lunar eclipse lasted less than 5 minutes, the shortest total lunar eclipse of the century. In fact, sliding just within the Earth's umbral shadow's northern edge, the lunar north stayed relatively bright, while a beautiful range of blue and red hues emerged across the rest of the Moon's Earth-facing hemisphere. The reddened light within the shadow that reaches the lunar surface is filtered through the lower atmosphere. Seen from a lunar perspective it comes from all the sunsets and sunrises around the edges of the silhouetted Earth. Close to the shadow's edge, the bluer light is still filtered through Earth's atmosphere, but originates as rays of sunlight pass through layers high in the upper stratosphere. That light is colored by ozone that absorbs red light and transmits bluer hues. In this sharp telescopic view of totality from Auckland, New Zealand, planet Earth, the Moon's north pole has been rotated to the top of the frame. via NASA http://ift.tt/1c6EOCJ


In the Heart of the Virgo Cluster

The Virgo Cluster of Galaxies is the closest cluster of galaxies to our Milky Way Galaxy. The Virgo Cluster is so close that it spans more than 5 degrees on the sky - about 10 times the angle made by a full Moon. With its heart lying about 70 million light years distant, the Virgo Cluster is the nearest cluster of galaxies, contains over 2,000 galaxies, and has a noticeable gravitational pull on the galaxies of the Local Group of Galaxies surrounding our Milky Way Galaxy. The cluster contains not only galaxies filled with stars but also gas so hot it glows in X-rays. Motions of galaxies in and around clusters indicate that they contain more dark matter than any visible matter we can see. Pictured above, the heart of the Virgo Cluster includes bright Messier galaxies such as Markarian's Eyes on the upper left, M86 just to the upper right of center, M84 on the far right, as well as spiral galaxy NGC 4388 at the bottom right. via NASA http://ift.tt/1C8VnUW


Searching for Water in the Solar System and Beyond

As NASA missions explore our solar system and search for new worlds, they are finding water in surprising places. Water is but one piece of our search for habitable planets and life beyond Earth, yet it links many seemingly unrelated worlds in surprising ways. Perhaps the most surprising water worlds are the five icy moons of Jupiter and Saturn that show strong evidence of oceans beneath their surfaces: Ganymede, Europa and Callisto at Jupiter, and Enceladus and Titan at Saturn. Scientists using NASA's Hubble Space Telescope recently provided powerful evidence that Ganymede has a saltwater, sub-surface ocean, likely sandwiched between two layers of ice. In this artist’s concept, the moon Ganymede orbits the giant planet Jupiter. The Hubble Space Telescope observed aurorae on the moon generated by Ganymede’s magnetic fields. A saline ocean under the moon’s icy crust best explains shifting in the auroral belts measured by Hubble. More: The Solar System and Beyond is Awash in Water Image Credit: NASA/ESA via NASA http://ift.tt/1a23AT3

NGC 3293: A Bright Young Star Cluster

Hot blue stars shine brightly in this beautiful, recently formed galactic or "open" star cluster. Open cluster NGC 3293 is located in the constellation Carina, lies at a distance of about 8000 light years, and has a particularly high abundance of these young bright stars. A study of NGC 3293 implies that the blue stars are only about 6 million years old, whereas the cluster's dimmer, redder stars appear to be about 20 million years old. If true, star formation in this open cluster took at least 15 million years. Even this amount of time is short, however, when compared with the billions of years stars like our Sun live, and the over-ten billion year lifetimes of many galaxies and our universe. Pictured, NGC 3293 appears just in front of a dense dust lane and red glowing hydrogen gas emanating from the Carina Nebula. via NASA http://ift.tt/1C9eRrw


International Space Station Flyover of Australia

From the International Space Station, NASA astronaut Scott Kelly (stationcdrkelly on Instagram) took this photograph and posted it to social media on April 6, 2015. Kelly wrote, "Australia. You are very beautiful. Thank you for being there to brighten our day. #YearInSpace" Kelly and Russian Federal Space Agency (Roscosmos) cosmonaut Mikhail Kornienko began their one-year mission aboard the space station on March 27. Most expeditions to the space station last four to six months. By doubling the length of this mission, researchers hope to better understand how the human body reacts and adapts to long-duration spaceflight. Image Credit: NASA via NASA http://ift.tt/1DEGXSp

Saturn, Tethys, Rings, and Shadows

Seen from ice moon Tethys, rings and shadows would display fantastic views of the Saturnian system. Haven't dropped in on Tethys lately? Then this gorgeous ringscape from the Cassini spacecraft will have to do for now. Caught in sunlight just below and left of picture center in 2005, Tethys itself is about 1,000 kilometers in diameter and orbits not quite five saturn-radii from the center of the gas giant planet. At that distance (around 300,000 kilometers) it is well outside Saturn's main bright rings, but Tethys is still one of five major moons that find themselves within the boundaries of the faint and tenuous outer E ring. Discovered in the 1980s, two very small moons Telesto and Calypso are locked in stable locations along Tethys' orbit. Telesto precedes and Calypso follows Tethys as the trio circles Saturn. via NASA http://ift.tt/1bYjVK6


Voorwerpjes in Space

Mysterious Hanny's Voorwerp, Dutch for "Hanny's Object", is really enormous, about the size of the Milky Way Galaxy and glowing strongly in the greenish light produced by ionized oxygen atoms. It is thought to be a tidal tail of material left by an ancient galaxy merger, illuminated and ionized by the outburst of a quasar inhabiting the center of distant spiral galaxy IC 2497. Its exciting 2007 discovery by Dutch schoolteacher Hanny van Arkel while participating online in the Galaxy Zoo project has since inspired a search and discovery of eight more eerie green cosmic features. Imaged in these panels by the Hubble Space Telescope, all eight appear near galaxies with energetic cores. Far outside their associated galaxies, these objects are also likely echoes of quasar activity, illuminated only as light from a core quasar outburst reaches them and ultimately fading tens of thousands of years after the quasar outburst itself has faded away. Of course a galaxy merger like the impending merger of our own Milky Way and the Andromeda Galaxy, could also trigger the birth of a quasar that would illuminate our distant future version of Hanny's Voorwerp. via NASA http://ift.tt/1xLDT4u


Sun and Moon Halo

Two pictures captured on April 1 are combined in this creative day and night composite. Separated in time by about 10 hours the images otherwise match, looking along the coast at Ă–stersund Sweden. The relative times were chosen to show the Sun and a nearly full Moon at the same place in the cold, early springtime sky. In the night scene Jupiter also shines above the waterfront lights, while Sun and Moon are both surrounded by a beautiful circular ice halo. The Sun and Moon halos really do align, each with an angular radius of 22 degrees. That radius is a constant, not determined by the brightness of Sun or Moon but only by the hexagonal geometry of atmospheric ice crystals and the reflection and refraction of light. Of course tomorrow, April 4, will find the Sun and Moon on opposite sides of planet Earth for a total lunar eclipse. via NASA http://ift.tt/1F7WN2X


Experimental Wing Tests Electric Propulsion Technologies

Leading Edge Asynchronous Propeller Technology (LEAPTech) project researchers at NASA's Armstrong Flight Research Center are performing ground testing of a 31-foot-span, carbon composite wing section with 18 electric motors. The LEAPTech project will test the premise that tighter propulsion-airframe integration, made possible with electric power, will deliver improved efficiency and safety, as well as environmental and economic benefits. The experimental wing, called the Hybrid-Electric Integrated Systems Testbed (HEIST), is mounted on a specially modified truck. Testing on the mobile ground rig assembly will provide valuable data and risk reduction applicable to future flight research. Instead of being installed in a wind tunnel, the HEIST wing section will remain attached to load cells on a supporting truss while the vehicle is driven at speeds up to 70 miles per hour across a dry lakebed at Edwards Air Force Base. LEAPTech to Demonstrate Electric Propulsion Technologies Image Credit: Joby Aviation via NASA http://ift.tt/19OVflo

The Owl and the Galaxy

via NASA http://ift.tt/1BPcKsE


Suiting Up for the Moon

How will cows survive on the Moon? One of the most vexing questions asked about space, scientists have spent decades debating this key issue. Finally, after extensive computer modeling and over a dozen midnight milkings, engineers have designed, built, and now tested the new Lunar Grazing Module (LGM), a multi-purpose celestial bovine containment system. By now, many of you will not be surprised to be wished a Happy April Fool's Day from APOD. To the best of our knowledge, there are no current plans to launch cows into space. For one reason, cows tend to be large animals that don't launch easily or cheaply. As friendly as cows may be, head-to-head comparisons show that robotic rovers are usually more effective as scientific explorers. The featured image is of a thought-provoking work of art named "Mooooonwalk" which really is on display at a popular science museum. via NASA http://ift.tt/1C5kJ4J


Corona from Svalbard

During a total solar eclipse, the Sun's extensive outer atmosphere, or corona, is an inspirational sight. Streamers and shimmering features that engage the eye span a brightness range of over 10,000 to 1, making them notoriously difficult to capture in a single photograph. But this composite of 29 telescopic images covers a wide range of exposure times to reveal the crown of the Sun in all its glory. The aligned and stacked digital frames were recorded in the cold, clear skies above the Arctic archipelago of Svalbard, Norway during the Sun's total eclipse on March 20 and also show solar prominences extending just beyond the edge of the solar disk. Remarkably, even small details on the dark night side of the New Moon can be made out, illuminated by sunlight reflected from a Full Earth. Of course, fortunes will be reversed on April 4 as a Full Moon plunges into the shadow of a New Earth, during a total lunar eclipse. via NASA http://ift.tt/1Fc1hba