omnianasa/nasa-apod-metadata huggingface dataset:
Mars Rover Races to Survive (2007-12-12)
The Martian rover Spirit is now in the race of its life.  The rolling robot is trying to reach an outpost to spend the winter, but it keeps getting bogged down in soft sand on Mars. Earth scientists hope that Spirit can reach a slope on the northern edge of the unusual feature dubbed Home Plate, before the end of this month when northern winter will be phasing in on Mars.   Reaching this slope will likely allow the rover to tilt enough toward the Sun to create a needed increase in the efficiency of its energy-absorbing solar panels.  This map shows the path of Spirit from July 2004 until just last month.
T Tauri and Hind's Variable Nebula (2007-12-13)
The orange star centered in this remarkable telescopic skyview is T Tauri, prototype of the class of T Tauri variable stars. Nearby it is a dusty yellow cosmic cloud historically known as Hind's Variable Nebula (NGC 1555/1554). Over 400 light-years away, at the edge of a molecular cloud, both star and nebula are seen to vary significantly in brightness but not necessarily at the same time, adding to the mystery of the intriguing region. T Tauri stars are now generally recognized as young (less than a few million years old), sun-like stars still in the early stages of formation. To further complicate the picture, infrared observations indicate that T Tauri itself is part of a multiple system and suggest that the associated Hind's Nebula may also contain a very young stellar object. The dramatic color image spans about 4 light-years at the estimated distance of T Tauri.
Apollo 17: Shorty Crater Panorama (2007-12-14)
In December of 1972, Apollo 17 astronauts Eugene Cernan and Harrison Schmitt spent about 75 hours on the Moon in the Taurus-Littrow valley, while colleague Ronald Evans orbited overhead. This sharp panorama is digitally stitched together from pictures taken by Cernan as he and Schmitt roamed the valley floor. Starting with a view of the imposing South Massif, scrolling the panorama to the right will reveal Schmitt and the lunar rover at the edge of Shorty Crater, near the spot where geologist Schmitt discovered orange lunar soil. The Apollo 17 crew returned with 110 kilograms of rock and soil samples, more than was returned from any of the other lunar landing sites. Now thirty five years later, Cernan and Schmitt are still the last to walk on the Moon.
Mountains of Creation (2007-12-15)
This fantastic skyscape lies at the eastern edge of giant stellar nursery W5, about 7,000 light-years away in the constellation Cassiopeia. An infrared view from the Spitzer Space Telescope, it features interstellar clouds of cold gas and dust sculpted by winds and radiation from a hot, massive star outside the picture (just above and to the right). Still swaddled within the cosmic clouds, newborn stars are revealed by Spitzer's penetrating gaze, their formation also triggered by the massive star. Fittingly dubbed "Mountains of Creation", these interstellar clouds are about 10 times the size of the analogous Pillars of Creation in M16, made famous in a 1995 Hubble Space Telescope view. W5 is also known as IC 1848 and together with IC 1805 it is part of a complex region popularly dubbed the Heart and Soul Nebulae. The Spitzer image spans about 70 light-years at the distance of W5.
The Holographic Principle (2007-12-16)
Is this picture worth a thousand words?  According to the Holographic Principle, the most information you can get from this image is about 3 x 1065 bits for a normal sized computer monitor.  The Holographic Principle, yet unproven, states that there is a maximum amount of information content held by regions adjacent to any surface.  Therefore, counter-intuitively, the information content inside a room depends not on the volume of the room but on the area of the bounding walls.  The principle derives from the idea that the Planck length, the length scale where quantum mechanics begins to dominate classical gravity, is one side of an area that can hold only about one bit of information.  The limit was first postulated by physicist Gerard 't Hooft in 1993.  It can arise from generalizations from seemingly distant speculation that the information held by a black hole is determined not by its enclosed volume but by the surface area of its event horizon.  The term "holographic" arises from a hologram analogy where three-dimension images are created by projecting light though a flat screen.  Beware, other people looking at the above image may not claim to see 3 x 1065 bits -- they might claim to see a teapot.
Saturn's Ancient Rings (2007-12-17)
How old are Saturn's rings?  No one is quite sure.  One possibility is that the rings formed relatively recently in our Solar System's history, perhaps only about 100 million years ago when a moon-sized object broke up near Saturn.  Evidence for a young ring age includes a basic stability analysis for rings, and the fact that the rings are so bright and relatively unaffected by numerous small dark meteor impacts.  New evidence, however, raises the possibility that some of Saturn's rings may be billions of years old and so almost as old as Saturn itself.   Inspection of images by the Saturn-orbiting Cassini spacecraft indicates that some of Saturn's ring particles temporarily bunch and collide, effectively recycling ring particles by bringing fresh bright ices to the surface.  Seen here, Saturn's rings were imaged in their true colors by the robotic Cassini in late October.  Icy bright Tethys, a moon of Saturn likely brightened by a sandblasting rain of ice from sister moon Enceladus, is visible in front of the darker rings.    APOD presents: Astronomy Pictures of the Year for 2007
Unusual Silica Rich Soil Discovered on Mars (2007-12-18)
You're rolling across Mars when you unexpectedly uncover some unusually light soil.   You stop. You turn. You return to inspect the soil and find out it is almost purely silica -- the main ingredient in quartz and glass.  Such soil has never been found on Mars before. What created this soil?  Since you are the robotic rover Spirit currently rolling across Mars, you send the images and data back to Earth for analysis.  Your scientist friends from the blue water planet say that such soil on Earth is usually created by either volcanic steam or a hot spring.  The second hypothesis in particular indicates, once again, a wet past for part of Mars, as possibly hot water saturated with silica deposited the white soil.  Intriguingly, on Earth, living microbes typically flourish under either condition.  Pictured above, the uncovered light soil is visible on the right.   APOD presents: Astronomy Pictures of the Year for 2007
Stars and Dust through Baade's Window (2007-12-19)
Billions of stars light up the direction toward the center of our Galaxy.  The vast majority of these stars are themselves billions of years old, rivaling their home Milky Way Galaxy in age.  Together with interstellar dust, these old stars combine to create this yellowish starscape. Although the opaque dust obscures the true Galactic center in visible light, there is a low density hole in the dust on the right of the image.  The region, named Baade's Window for the German astronomer who studied it, is used to inspect distant stars and to determine the internal geometry of the Milky Way.  Baade's Window lies toward the constellation of the Archer (Sagittarius).   APOD presents: Astronomy Pictures of the Year for 2007
Reflections on the 1970s (2007-12-20)
The 1970s are sometimes ignored by astronomers. In particular, this beautiful grouping of reflection nebulae in Orion - NGC 1977, NGC 1975, and NGC 1973 - are usually overlooked in favor of the substantial glow from the nearby stellar nursery better known as the Orion Nebula. Found along Orion's sword just north of the bright Orion Nebula complex, these reflection nebulae are also associated with Orion's giant molecular cloud about 1,500 light-years away, but are dominated by the characteristic blue color of interstellar dust reflecting light from hot young stars. North is down in this sharp color telescopic image from New South Wales, Australia, so the more familiar Orion Nebula borders the top of the view. NGC 1977 stretches across the field just above center, separated from NGC 1973 (below left) and NGC 1975 (below right) by darker regions of obscuring dust. Many northern hemisphere observers claim to see the general shape of a running man in the cosmic dust cloud but, of course, they're looking at the view upside down.   APOD presents: Astronomy Pictures of the Year for 2007
Horizon to Horizon (2007-12-21)
Scroll right and journey from horizon to horizon as your gaze sweeps through the zenith in the night sky over Beg-Meil, France. Recorded on December 13th, the entertaining panorama (image key) covers 210 degrees in 21 separate exposures, beginning on the beach with bright star Sirius rising in the southeast. Look up (pan right) to encounter the nebula rich constellation of Orion and continue on to find the lovely Pleiades star cluster. Farther along, higher in the sky, is the famous Comet Holmes, still gracing the northern hemisphere's night with its remarkable expanding coma. Finally, just before diving into the urban glow from city lights along the northwestern horizon (far right), check out the double star cluster in Perseus and take in the cosmic streak of a bright Geminid Meteor.   APOD presents: Astronomy Pictures of the Year for 2007
Tyrrhenian Sea and Solstice Sky (2007-12-22)
Today the Solstice occurs at 0608 Universal Time, the Sun reaching its southernmost declination in planet Earth's sky. Of course, the December Solstice marks the beginning of winter in the northern hemisphere and summer in the south. When viewed from northern latitudes, the Sun will make its lowest arc through the sky along the southern horizon. So in the north, the Solstice day has the shortest length of time between sunrise and sunset and fewest hours of daylight.  This striking composite image follows the Sun's path through the December Solstice day of 2005 in a beautiful blue sky, looking down the Tyrrhenian Sea coast from Santa Severa toward Fiumicino, Italy. The view covers about 115 degrees in 43 separate, well-planned exposures from sunrise to sunset.   APOD presents: Astronomy Pictures of the Year for 2007
Moon and Mars Tonight (2007-12-23)
The Full Moon and a brilliant, ruddy Mars will share the sky tonight. Skygazers can easily enjoy the celestial pairing as the two are separated by a degree or even less. In fact, seen from parts of northern North America and Europe, the Moon will actually occult (pass in front of) the Red Planet. Mars is so bright because it is near opposition, opposite the Sun in Earth's sky and near its closest approach to planet Earth. But Mars is not nearly as bright as the Moon, also opposite the Sun tonight. In this striking preview of tonight's sky show, backyard astronomer John Harms was able to photograph an almost Full Moon near Mars last month. His simple, single exposure relied on clouds to block some of the overwhelming moonlight.   APOD presents: Astronomy Pictures of the Year for 2007
Emission Nebula IC 1396 (2007-12-24)
Sprawling across hundreds of light-years, emission nebula IC 1396 mixes glowing cosmic gas and dark dust clouds. Stars are forming in this area, only about 3,000 light-years from Earth. This detailed view was created in light primarily emitted by hydrogen gas, recorded through a filter that narrowly transmits a wavelength characteristic of glowing hydrogen atoms in the nebula. Among the intriguing dark shapes within IC 1396, the winding Elephant's Trunk nebula lies just left center. IC 1396 lies in the high and far off constellation of Cepheus.   APOD presents: Astronomy Pictures of the Year for 2007
Mars and Orion Over Monument Valley (2007-12-25)
Welcome to The World At Night. Sharing the night sky seen around the world, this view from Monument Valley, USA includes a picturesque foreground of famous buttes. Buttes are composed of hard rock left behind after water eroded away the surrounding soft rock.   The two buttes on the image left are known as the Mittens, while Merrick Butte is on the right. Recorded just last week, planet Mars is at the left of the skyscape, a glowing beacon of orange that is the brightest object in the frame.  To the right of Mars lies the constellation of Orion. Betelgeuse is the reddish star near the center and the Belt of Orion and the Orion Nebula are farther right. Finally, the bright blue star Rigel appears above Merrick Butte in this stunning view of  The World At Night.   APOD presents: Astronomy Pictures of the Year for 2007
Trifid Pillars and Jets (2007-12-26)
Dust pillars are like interstellar mountains.  They survive because they are more dense than their surroundings, but they are being slowly eroded away by a hostile environment.  Visible in the above picture is the end of a huge gas and dust pillar in the  Trifid Nebula, punctuated by a smaller pillar pointing up and an unusual jet pointing to the left.  The pink dots are newly formed low-mass stars. A star near the small pillar's end is slowly being stripped of its accreting gas by radiation from a tremendously brighter star situated off the above picture to the upper right.  The jet extends nearly a light-year and would not be visible without external illumination.  As gas and dust evaporate from the pillars, the hidden stellar source of this  jet will likely be uncovered, possibly over the next 20,000 years.   APOD presents: Astronomy Pictures of the Year for 2007
Earth at Twilight (2007-12-27)
No sudden, sharp boundary marks the passage of day into night in this gorgeous view of ocean and clouds over our fair planet Earth. Instead, the shadow line or terminator is diffuse and shows the gradual transition to darkness we experience as twilight. With the Sun illuminating the scene from the right, the cloud tops reflect gently reddened sunlight filtered through the dusty troposphere, the lowest layer of the planet's nurturing atmosphere. A clear high altitude layer, visible along the dayside's upper edge, scatters blue sunlight and fades into the blackness of space. This picture actually is a single digital photograph taken in June of 2001 from the International Space Station orbiting at an altitude of 211 nautical miles.   APOD presents: Astronomy Pictures of the Year for 2007
A Beautiful Boomerang Nebula (2007-12-28)
This symmetric cloud dubbed the Boomerang Nebula was created by a high-speed wind of gas and dust blowing from an aging central star at speeds of nearly 600,000 kilometers per hour.  The rapid expansion has cooled molecules in the nebular gas to about one degree above absolute zero - colder than even the cosmic background radiation - making it the coldest known region in the distant Universe.  Shining with light from the central star reflected by dust, the frigid Boomerang Nebula is believed to be a star or stellar system evolving toward the planetary nebula phase.  This Hubble image was recorded using polarizing filters (analogous to polaroid sunglasses) and color coded by the angle associated with the polarized light.  The gorgeous result traces the small dust particles responsible for polarizing and scattering the light. The Boomerang Nebula spans about one light year and lies about 5,000 light years away toward the constellation Centaurus.   APOD presents: Astronomy Pictures of the Year for 2007
Saturn's Infrared Glow (2007-12-29)
Known for its bright ring system and many moons, gas giant Saturn looks strange and unfamiliar in this false-color view from the Cassini spacecraft. In fact, in this Visual and Infrared Mapping Spectrometer (VIMS) mosaic the famous rings are almost invisible, seen edge-on cutting across picture center. The most striking contrast in the image is along the terminator or boundary between night and day. To the right (day side) blue-green hues are visible sunlight reflected from Saturn's cloud tops. But on the left (night side) in the absence of sunlight, the lantern-like glow of infrared radiation from the planet's warm interior silhouettes features at Saturn's deeper cloud levels.   APOD presents: Astronomy Pictures of the Year for 2007
Mammatus Clouds Over Mexico (2007-12-30)
Normal cloud bottoms are flat because moist warm air that rises and cools will condense into water droplets at a very specific temperature, which usually corresponds to a very specific height.  After water droplets form that air becomes an opaque cloud.  Under some conditions, however, cloud pockets can develop that contain large droplets of water or ice that fall into clear air as they evaporate.  Such pockets may occur in turbulent air near a  thunderstorm, being seen near the top of an anvil cloud, for example.  Resulting mammatus clouds can appear especially dramatic if sunlit from the side.  These mammatus clouds were photographed over Monclova, Mexico.   APOD presents: Astronomy Pictures of the Year for 2007
A Year of Spectacular Comets (2007-12-31)
Two spectacular comets graced Earth's skies during 2007.  Both comets became bright enough to be seen by the unaided eye of the casual sky enthusiast.  Early in 2007, Comet McNaught grew brighter than any comet in 40 years, displaying a beautiful dust tail that flowed across the sky.  Comet McNaught (c/2006 P1) became known as the Great Comet of 2007, sported unusual striations in its expansive dust tail, and showed unexpectedly complex chemistry in its ion tail.   Toward the year's end, normally docile and faint Comet Holmes brightened suddenly and unexpectedly to naked eye visibility.  Remarkably, Comet 17P/Holmes stayed bright for weeks even though it lies beyond the orbit of Mars.  No distant comet in recent history has remained so bright for so long.  In this view, a white Comet Holmes was photographed in early December posing with the Heart and Soul Nebulas.   APOD presents: Astronomy Pictures of the Year for 2007
Fireworks Galaxy NGC 6946 (2011-01-01)
Celebrate the New Year with the Fireworks Galaxy! Also known as NGC 6946, the big, beautiful spiral galaxy is located just 10 million light-years away, behind a veil of foreground dust and stars in the high and far-off constellation of Cepheus. From our vantage point in the Milky Way Galaxy, we see NGC 6946 face-on. In this colorful cosmic portrait, the galaxy's colors change from the yellowish light of old stars in the core to young blue star clusters and reddish star forming regions along the loose, fragmented spiral arms. NGC 6946 is bright in infrared light and rich in gas and dust, exhibiting a furious rate of star formation. Nearly 40,000 light-years across, the nearby spiral is fittingly referred to as the Fireworks Galaxy. Over the last 100 years, at least nine supernovae, the death explosions of massive stars, were discovered in NGC 6946. By comparison, the average rate for supernovae in the Milky Way is about 1 per century.
Looking Back at an Eclipsed Earth (2011-01-02)
Here is what the Earth looks like during a solar eclipse. The shadow of the Moon can be seen darkening part of Earth. This shadow moved across the Earth at nearly 2000 kilometers per hour. Only observers near the center of the dark circle see a total solar eclipse - others see a partial eclipse where only part of the Sun appears blocked by the Moon. This spectacular picture of the 1999 August 11 solar eclipse was one of the last ever taken from the Mir space station. The two bright spots that appear on the upper left are thought to be Jupiter and Saturn. Mir was deorbited in a controlled re-entry in 2001.
Winter Hexagon Over Stagecoach Colorado (2011-01-03)
If you can find Orion, you might be able to find the Winter Hexagon.  The Winter Hexagon involves some of the brightest stars visible, together forming a large and easily found pattern in the winter sky of Earth's northern hemisphere.  The stars involved can usually be identified even in the bright night skies of a big city, although here they appear over darker Stagecoach, Colorado, USA..  The six stars that compose the Winter Hexagon are Aldebaran, Capella, Castor (and Pollux), Procyon, Rigel, and Sirius.  Here, the band of our Milky Way Galaxy runs through the center of the Winter Hexagon, while the Pleiades open star cluster is visible just above. The Winter Hexagon asterism engulfs several constellations including much of the iconic steppingstone Orion.   Best Astronomy Images: APOD Editor to speak in Philadelphia and New York City this week
A Green Flash from the Sun (2011-01-04)
Many think it is just a myth.  Others think it is true but its cause isn't known.  Adventurers pride themselves on having seen it.  It's a green flash from the Sun.  The truth is the green flash does exist and its cause is well understood.  Just as the setting Sun disappears completely from view, a last glimmer appears startlingly green.  The effect is typically visible only from locations with a low, distant horizon, and lasts just a few seconds. A green flash is also visible for a rising Sun, but takes better timing to spot.  A dramatic green flash, as well as an even more rare blue flash, was caught in the above photograph recently observed during a sunset visible from Teide Observatory at Tenerife, Cannary Islands, Spain.  The Sun itself does not turn partly green or blue -- the effect is caused by layers of the Earth's atmosphere acting like a prism.   Best Astronomy Images: APOD Editor to speak in Philadelphia tomorrow night and NYC Friday
Eclipsing the Sun (2011-01-05)
Skywatchers throughout much of Europe, North Africa, and Central Asia, were treated to the first eclipse of the new year on January 4, a partial eclipse of the Sun. But traveling to the area around Muscat, capital city of Oman, photographer Thierry Legault planned to simultaneously record two eclipses on that date, calculating from that position, for a brief moment, both the Moon and the International Space Station could be seen in silhouette, crossing the Sun. His sharp, 1/5000th second exposure is shown here, capturing planet Earth's two largest satellites against the bright solar disk. As the partial solar eclipse unfolded, the space station (above and left of center) zipped across the scene in less than 1 second, about 500 kilometers from the photographer's telescope and camera. Of course, the Moon was 400 thousand kilometers away. Complete with sunspots, the Sun was 150 million kilometers distant.   Best Astronomy Images: APOD Editor to speak in Philadelphia tonight and NYC Friday
Sunrise, Moonrise (2011-01-06)
For many Europeans, the Sun and New Moon rose together on January 4 in a partial solar eclipse. Arriving close on the heels of the new year, it was the first of a series of four(!) partial solar eclipses due in 2011. This composite image documents the graceful celestial event in colorful morning skies over Graz, Austria. Beginning before sunrise, frames were taken to record the position and progress of the eclipse every 15 minutes. As Sun and Moon rose above the eastern horizon, the town of Graz is seen bathed in warming sunlight only partially blocked by the New Moon, spreading beneath the town's landmark clock tower.   Best Astronomy Images: APOD Editor to speak in NYC Friday
Sunset, Moonset (2011-01-07)
Seen from central and northern Asia, the Sun and New Moon set together on January 4, in a partial solar eclipse. Close to its maximum phase, the eclipse is captured near the moment of sunset in this wintry scene from the bank of the Berd River near Novosibirsk, Siberia, Russia. An evocative view in fading light, the picture looks toward the western horizon across a snowy, frozen landscape. Along with offset Sun and Moon, the dimly lit sky includes an industrial smoke plume and airplane contrail.   Best Astronomy Images: APOD Editor to speak in NYC tonight.