omnianasa/nasa-apod-metadata huggingface dataset:
Exceptional Rocket Waves Destroy Sun Dog (2010-02-23)
What created those rocket waves, and why did they destroy that sun dog? Close inspection of the above image shows not only a rocket rising near the center, but unusual air ripples around it and a colorful sundog to the far right. The rocket, carrying the Solar Dynamics Observatory (SDO), lifted off two weeks ago from Cape Canaveral, Florida, USA into a cold blue sky.  The SDO is designed to observe the Sun continuously over the next several years, exploring the Sun's atmosphere at high resolution and fast time scales. The air ripples -- seen about one minute after launch -- were unexpected, as was the sudden disappearance of the sundog after the ripples passed. Noticed and recorded by several onlookers, there has been much speculation about the origin of the ripples.  An ongoing discussion about them can be joined here in APOD's discussion board the Asterisk. A leading hypothesis holds that the ripples resulted from a sonic boom created as the rocket broke the sound barrier, which then jumbled a thin layer of ice crystals that were aligned to create the sundog. Lingering questions include why other rocket launches don't produce air ripples as noticeable, and why the ripples appeared more prominent above the rocket. If you know of images of any other aircraft or spacecraft that have produced similar air ripples, please post them to the discussion thread -- they may be help create a better understanding of the effect.
Astronaut Installs Panoramic Space Window (2010-02-24)
This space job was almost complete. Floating just below the International Space Station, astronaut Nicholas Patrick put some finishing touches on the newly installed cupola space windows last week. Patrick was a mission specialist onboard the recently completed space shuttle Endeavor's STS-130 mission to the ISS. Pictured, Patrick floats near the outermost of seven windows on the new cupola of the just-installed Tranquility module.   Patrick hovers about 340 kilometers over the Earth's surface, well in front of the blue sky, blue water, and white clouds pictured far in the background. In the above image, covers on windows three and four were in place and clearly labelled.  Images from inside the ISS's new panoramic cupola are now available.
Edge-on Spiral Galaxy NGC 891 (2010-02-25)
This beautiful cosmic portrait features NGC 891. The spiral galaxy spans about 100 thousand light-years and is seen almost exactly edge-on from our perspective. In fact, about 30 million light-years distant in the constellation Andromeda, NGC 891 looks a lot like our Milky Way. At first glance, it has a flat, thin, galactic disk and a central bulge cut along the middle by regions of dark obscuring dust. Also apparent in NGC 891's edge-on presentation are filaments of dust that extend hundreds of light-years above and below the center line. The dust has likely been blown out of the disk by supernova explosions or intense star formation activity. Faint neighboring galaxies can also been seen near this galaxy's disk.
Chasing Carina (2010-02-26)
A jewel of the southern sky, the Great Carina Nebula, aka NGC 3372, spans over 300 light-years. Near the upper right of this expansive skyscape, it is much larger than the more northerly Orion Nebula. In fact, the Carina Nebula is one of our galaxy's largest star-forming regions and home to young, extremely massive stars, including the still enigmatic variable Eta Carinae, a star with well over 100 times the mass of the Sun. Nebulae near the center of the 10 degree wide field include NGC 3576 and NGC 3603. Near center at the top of the frame is open star cluster NGC 3532, the Wishing Well Cluster. More compact, NGC 3766, the Pearl Cluster, can be spotted at the left. Anchoring the lower left of the cosmic canvas is another large star-forming region, IC 2948/2944 with embedded star cluster Collinder 249. That region is popularly known as the Running Chicken Nebula.
Dawn's Endeavour (2010-02-27)
On February 21st, the Space Shuttle Endeavour and the International Space Station (ISS) flew through the sky near dawn over Whitby, Ontario, Canada. Along with star trails, both were captured in this single time exposure. Glinting in sunlight 350 kilometers above the Earth, Endeavour slightly preceeded the ISS arcing over the horizon. But the brighter trail and the brighter flare belongs to the space station just visited by Endeavour. Near the completion of the STS-130 mission, hours later Endeavour made a night landing at Kennedy Space Center.
Pauli Exclusion Principle: Why You Don't Implode (2010-02-28)
Why doesn't matter just bunch up?  The same principle that keeps neutron stars and white dwarf stars from imploding also keeps people from imploding and makes normal matter mostly empty space. The observed reason is known as the Pauli Exclusion Principle.  The principle states that identical fermions -- one type of fundamental matter -- cannot be in the same place at the same time and with the same orientation.  The other type of matter, bosons, do not have this property, as demonstrated clearly by recently created Bose-Einstein condensates.  Earlier this decade, the Pauli Exclusion Principle was demonstrated graphically in the above picture of clouds of two isotopes of lithium -- the left cloud composed of bosons while the right cloud is composed of fermions.  As temperature drops, the bosons bunch together, while the fermions better keep their distance.  The reason why the Pauli Exclusion Principle is true and the physical limits of the principle are still unknown.
Slope Streaks in Acheron Fossae on Mars (2010-03-01)
What creates these picturesque dark streaks on Mars? No one knows for sure.  A leading hypothesis is that streaks like these are caused by fine grained sand sliding down the banks of troughs and craters. Pictured above, dark sand appears to have flowed hundreds of meters down the slopes of Acheron Fossae.  The sand appears to flow like a liquid around boulders, and, for some reason, lightens significantly over time. This sand flow process is one of several which can rapidly change the surface of Mars, with other processes including dust devils, dust storms, and the freezing and melting of areas of ice. The above image was taken by the HiRise camera on board the Mars Reconnaissance Orbiter which has been orbiting Mars since 2006.  Acheron Fossae is a 700 kilometer long trough in the Diacria quadrangle of Mars.
M78 and Reflecting Dust Clouds in Orion (2010-03-02)
An eerie blue glow and ominous columns of dark dust highlight M78 and other bright reflection nebula in the constellation of Orion.  The dark filamentary dust not only absorbs light, but also reflects the light of several bright blue stars that formed recently in the nebula.  Of the two reflection nebulas pictured above, the more famous nebula is M78, in the image center, while NGC 2071 can be seen to its lower left. The same type of scattering that colors the daytime sky further enhances the blue color.  M78 is about five light-years across and visible through a small telescope.  M78 appears above only as it was 1600 years ago, however, because that is how long it takes light to go from there to here.  M78 belongs to the larger Orion Molecular Cloud Complex that contains the Great Nebula in Orion and the Horsehead Nebula.
The International Space Station from Above (2010-03-03)
The International Space Station (ISS) is the largest human-made object ever to orbit the Earth.  The ISS is so large that it can be seen drifting overhead with the unaided eye, and is frequently imaged from the ground in picturesque fashion.  Last month, the station was visited again by space shuttle, which resupplied the station and added a new module.   The ISS is currently operated by the Expedition 22 crew, now consisting five astronauts including two supplied by USA's NASA, two by Russia's RKA, and one by Japan's JAXA.   After departing the ISS, the crew of the space shuttle Endeavour captured the above spectacular vista of the orbiting space city high above the clouds, waters, and lands of Earth.  Visible components include modules, trusses, and expansive solar arrays that gather sunlight that is turned into needed electricity.   Share Quiz: Can anyone identify the landscape behind the space station?
NGC 4565: Galaxy on Edge (2010-03-04)
Magnificent spiral galaxy NGC 4565 is viewed edge-on from planet Earth. Also known as the Needle Galaxy for its narrow profile, bright NGC 4565 is a stop on many telescopic tours of the northern sky, in the faint but well-groomed constellation Coma Berenices. This sharp, colorful image reveals the galaxy's bulging central core cut by obscuring dust lanes that lace NGC 4565's thin galactic plane. An assortment of other galaxies is included in the pretty field of view. Neighboring galaxy NGC 4562 is at the upper right. NGC 4565 itself lies about 40 million light-years distant, spanning some 100,000 light-years.  Easily spotted with small telescopes, sky enthusiasts consider NGC 4565 to be a prominent celestial masterpiece Messier missed.
Deep Auriga (2010-03-05)
The plane of our Milky Way Galaxy runs right through Auriga, the Charioteer. A good part of the ancient northern constellation's rich collection of nebulae and star clusters is featured in this expansive, 10 degree wide skyscape. Bright star Elnath lies near the bottom right, linking Auriga to another constellation, Taurus, the Bull. Three open star clusters, Charles Messier's M36, M37, and M38 line up in the dense star field above and left of Elnath, familiar to many binocular-equipped skygazers. But the deep exposure also brings out the reddish emission nebulae of star-forming regions IC 405, IC 410, and IC 417. E. E. Barnard's dark nebulae B34 and B226 just stand out against a brighter background. For help identifying even more of Auriga's deep sky highlights, put your cursor over the image.
Pillar at Sunset (2010-03-06)
Reddened light from the setting Sun illuminates the cloud banks hugging this snowy, rugged terrain. Inspiring a moment of quiet contemplation, the sunset scene included a remarkable pillar of light that seemed to connect the clouds in the sky with the mountains below. Known as a Sun pillar, the luminous column was produced by sunlight reflecting from flat, six-sided ice crystals formed high in the cold atmosphere and fluttering toward the ground. Last Monday, astronomers watched this Sun pillar slowly fade, as the twilight deepened and clearing, dark skies came to Mt. Jelm and the Wyoming Infrared Observatory.
Spirit Rover at Engineering Flats on Mars (2010-03-07)
Is it art?  If so, the paintbrush was the Spirit robotic rover, the canvas was the soil on Mars, and the artists were the scientists and engineers of the Mars Exploration Rover Mission.  This panoramic picture, created in 2004 and shown above compressed horizontally, was mostly unintentional -- the MERS team was primarily instructing Spirit to investigate rocks in and around Hank's Hollow in a location called Engineering Flats on Mars. After creating the ground display with its treads, the Spirit rover was instructed to photograph the area along with itself in shadow.  In 2010 as winter approaches in northern Mars, Spirit, still mired in sand, has been placed in an energy saving "hibernating" mode until spring arrives and more direct sunlight might be used to power the robotic explorer.
Mars Over the Allalinhorn (2010-03-08)
What's that bright object in the sky? A common question with answers that vary by time and season, the quick answer just after sunset in middle of last month, from the northern hemisphere, was Mars. The above picturesque panorama, taken during a ski trip from the Alps in Switzerland, shows not only Mars, but much more.  Pine trees line the foreground, while numerous slopes leading up to the snow covered Allalinhorn mountain are visible in the distance.  Stars dot the background, with the Beehive star cluster (M44) visible just below and to the left of Mars, while stars Castor and Pollux peek through the tree tops to the Mars' upper right.  Mars will remain bright and in the constellation of the Crab (Cancer) until mid-May.
Galaxies Beyond the Heart: Maffei 1 and 2 (2010-03-09)
The two galaxies on the far left were unknown until 1968.  Although they would have appeared as two of the brighter galaxies on the night sky, the opaque dust of the central band of our Milky Way Galaxy had obscured them from being seen in visible light. The above image in infrared light taken by the recently launched Wide-Field Infrared Survey Explorer (WISE), however, finds these galaxies in great detail far behind -- but seemingly next to -- the photogenic Heart nebula (IC 1805).  The spiral galaxy near the top is the easiest to spot and is known as Maffei 2.  Just below and to its right is fuzzy-looking  Maffei 1, the closest giant elliptical galaxy to Earth. The above false-colored image spans three full moons from top to bottom.  The Maffei galaxies each span about 15,000 light years across and lie about 10 million light years away toward the constellation of the Queen of Ethiopia (Cassiopeia).  On the image right, stars, gaseous filaments, and warm dust highlight a detailed infrared view of the Heart nebula.
Saturn's Moon Helene from Cassini (2010-03-10)
What's happening on the surface of Saturn's moon Helene? The moon was imaged in unprecedented detail last week as the robotic Cassini spacecraft orbiting Saturn swooped to within two Earth diameters of the diminutive moon. Although conventional craters and hills appear, the above raw and unprocessed image also shows terrain that appears unusually smooth and streaked. Planetary astronomers will be inspecting these detailed images of Helene to glean clues about the origin and evolution of the 30-km across floating iceberg. Helene is also unusual because it circles Saturn just ahead of the large moon Dione, making it one of only four known Saturnian moons to occupy a gravitational well known as a stable Lagrange point.
Yukon Aurora with Star Trails (2010-03-11)
Fixed to a tripod, a camera can record graceful trails traced by stars as planet Earth rotates on its axis. But at high latitudes during March and April, it can also capture an aurora shimmering in the night. In fact, the weeks surrounding the equinox, in both spring and fall, offer a favorable season for aurora hunters. The possibilities are demonstrated in this beautiful moonlit vista from northwestern Canadian territory the Yukon. It was taken during the early morning of March 1, off the Klondike Highway about 60 kilometers south of Dawson City. To compose the picture, many short exposures were digitally combined to follow the concentric star trail arcs while including the greenish auroral curtains also known as the northern lights.
JWST: Mirrors and Masked Men (2010-03-12)
Who are these masked men? Technicians from Ball Aerospace and NASA at Marshall Space Flight Center's X-ray and Cryogenic Facility, of course, testing primary mirror segments of the James Webb Space Telescope (JWST). Scheduled for launch in 2014, JWST will be optimized for the infrared exploration of the early Universe, utilizing a primary mirror 21.3 feet across, composed of 18 hexagonal segments. Here, a group of JWST mirror segments are being prepared for tests to assure they meet the exacting mission requirements. The technicians' suits and masks help prevent contamination of the mirror surfaces. At the Marshall X-ray and Cryogenic Facility, the mirrors are tested in the large circular chamber after evacuating the air and cooling the chamber to -400 degrees Fahrenheit (only 60 degrees above absolute zero). The extremely low pressure and temperature simulate the JWST mirror operating environment in space. JWST mirror segment testing will continue for the next 18 months.
Centaurus A (2010-03-13)
Only 11 million light-years away, Centaurus A is the closest active galaxy to planet Earth. Spanning over 60,000 light-years, the peculiar elliptical galaxy, also known as NGC 5128, is featured in this sharp color image. Centaurus A is apparently the result of a collision of two otherwise normal galaxies resulting in a fantastic jumble of star clusters and imposing dark dust lanes. Near the galaxy's center, left over cosmic debris is steadily being consumed by a central black hole with a billion times the mass of the Sun. As in other active galaxies, that process likely generates the radio, X-ray, and gamma-ray energy radiated by Centaurus A.
Binary Black Hole in 3C 75 (2010-03-14)
What's happening in the middle of this massive galaxy? There, two bright sources at the center of this composite x-ray (blue)/radio (pink) image are thought to be co-orbiting supermassive black holes powering the giant radio source 3C 75. Surrounded by multimillion degree x-ray emitting gas, and blasting out jets of relativistic particles the supermassive black holes are separated by 25,000 light-years. At the cores of two merging galaxies in the Abell 400 galaxy cluster they are some 300 million light-years away. Astronomers conclude that these two supermassive black holes are bound together by gravity in a binary system in part because the jets' consistent swept back appearance is most likely due to their common motion as they speed through the hot cluster gas at 1200 kilometers per second. Such spectacular cosmic mergers are thought to be common in crowded galaxy cluster environments in the distant universe. In their final stages the mergers are expected to be intense sources of gravitational waves.
Illuminated Cloud Trails Above Greece (2010-03-15)
It may appear to be day, but it's night.  Those wondrous orange streaks may appear to be rays from the setting Sun, but they're actually thin clouds illuminated by the Moon as they quickly streaked toward the distant horizon. The thick clouds on the far left may appear to have many layers, but actually they are just a few simple clouds captured on numerous separate exposures.  What is surely true, though, is that the above time lapse image sequence was taken over two hours, about two weeks ago, in Sounio, Greece.  Also, those really are star trails swirling around the north star Polaris on the upper right of the image.  But what about the building in the foreground?  It may appear to be a famous ancient structure, but it's actually a small deserted church built only last century.    Your opinion requested: Is APOD a blog?
Detailed View of a Solar Eclipse Corona (2010-03-16)
Only in the fleeting darkness of a total solar eclipse is the light of the solar corona easily visible. Normally overwhelmed by the bright solar disk, the expansive corona, the sun's outer atmosphere, is an alluring sight. But the subtle details and extreme ranges in the corona's brightness, although discernible to the eye, are notoriously difficult to photograph. Pictured above, however, using multiple images and digital processing, is a detailed image of the Sun's corona taken during the 2008 August total solar eclipse from Mongolia.  Clearly visible are intricate layers and glowing caustics of an ever changing mixture of hot gas and magnetic fields. Bright looping prominences appear pink just above the Sun's limb. The next total solar eclipse will be in July but will only be visible in a thin swath of Earth crossing the southern Pacific Ocean and South America.
Phobos from Mars Express (2010-03-17)
Why is this small object orbiting Mars?  The origin of Phobos, the larger of the two moons orbiting Mars, remains unknown.  Phobos and Deimos appear very similar to C-type asteroids, yet gravitationally capturing such asteroids, circularizing their orbits, and dragging them into Mars' equatorial plane seems unlikely.  Pictured above is Phobos as it appeared during last week's flyby of ESA's Mars Express, a robotic spacecraft that began orbiting Mars in 2003. Visible in great detail is Phobos' irregular shape, strangely dark terrain, numerous unusual grooves, and a spectacular chain of craters crossing the image center.   Phobos spans only about 25 kilometers in length and does not have enough gravity to compress it into a ball.  Phobos orbits so close to Mars that sometime in the next 20 million years, tidal deceleration will break up the  rubble moon into a ring whose pieces will slowly spiral down and crash onto the red planet. The Russian mission Phobos-Grunt is scheduled to launch and land on Phobos next year.
Fermi Catalogs the Gamma-ray Sky (2010-03-18)
What shines in the gamma-ray sky? The most complete answer yet to that question is offered by the Fermi Gamma-ray Space Telescope's first all-sky catalog. Fermi's sources of cosmic gamma-rays feature nature's most energetic particle accelerators, ultimately producing 100 MeV to 100 GeV photons, photons with more than 50 million to 50 billion times the energy of visible light. Distilled from 11 months of sky survey data using Fermi's Large Area Telescope (LAT), the 1,451 cataloged sources include energetic star burst galaxies and active galactic nuclei (AGN) far beyond the Milky Way. But within our own galaxy are many pulsars (PSR) and pulsar wind nebulae (PWN), supernova remnants (SNR), x-ray binary stars (HXB) and micro-quasars (MQO). Fermi's all sky map is shown centered on the Milky Way with the diffuse gamma-ray emission from the Galactic plane running horizontally through the frame. To locate the cataloged gamma-ray sources, just slide your cursor over the map. For now, 630 of the sources cataloged at gamma-ray energies remain otherwise unidentified, not associated with sources detected at lower energies.
The Seagull and the Duck (2010-03-19)
Seen as a seagull and a duck, these nebulae are not the only cosmic clouds to evoke images of flight. But both are winging their way across this broad celestial landscape, spanning almost 7 degrees across planet Earth's night sky toward the constellation Canis Major. The expansive Seagull (upper left) is itself composed of two major cataloged emission nebulae. Brighter NGC 2327 forms the head with the more diffuse IC 2177 as the wings and body. Impressively, the Seagull's wingspan would correspond to about 250 light-years at an estimated distance of 3,800 light-years. At the lower right, the Duck appears much more compact and would span only about 50 light-years given its 15,000 light-year distance estimate. Blown by energetic winds from an extremely massive, hot star near its center, the Duck nebula is cataloged as NGC 2359. Of course, the Duck's thick body and winged appendages also lend it a more dramatic popular moniker -- Thor's Helmet.
Zodiacal Light Vs. Milky Way (2010-03-20)
Ghostly Zodiacal light, featured near the center of this remarkable panorama, is produced as sunlight is scattered by dust in the Solar System's ecliptic plane. In the weeks surrounding the March equinox (today at 1732 UT) Zodiacal light is more prominent after sunset in the northern hemisphere, and before sunrise in the south, when the ecliptic makes a steep angle with the horizon. In the picture, the narrow triangle of Zodiacal light extends above the western horizon and seems to end at the lovely Pleiades star cluster. Arcing above the Pleiades are stars and nebulae along the plane of our Milky Way Galaxy. Recorded on March 10 from Teide National Park on the island of Tenerife, the vista is composed of 4 separate pictures spanning over 180 degrees.
Equinox + 1 (2010-03-21)
Twice a year, at the Spring and Fall equinox, the Sun rises due east. In an emphatic demonstration of this celestial alignment, photographer Joe Orman recorded this inspiring image of the Sun rising exactly along the east-west oriented Western Canal, in Tempe, Arizona, USA. But he waited until one day after the northern Spring equinox, in 2001, to photograph the striking view. Why was the rising Sun due east one day after the equinox? At Tempe's latitude the Sun rises at an angle, arcing southward as it climbs above the horizon. Because the distant mountains hide the true horizon, the Sun shifts slightly southward by the time it clears the mountain tops. Waiting 24 hours allowed the Sun to rise just north of east and arc back to an exactly eastern alignment for the photo. Today is another Equinox + 1 day, with the Sun crossing the celestial equator yesterday at about 17:32 Universal Time.