omnianasa/nasa-apod-metadata huggingface dataset:
A Galactic Star Forming Region in Infrared (2007-09-24)
How do stars form?  To help study this complex issue, astronomers took a deep image in infrared light of an active part of our Milky Way Galaxy where star formation is rampant.  In IRDC G11.11-0.11, thick clouds of dust and gas are congealing into stars that are so dark that humans living there would see an empty night sky.  The image, though, taken last year by the Spitzer Space Telescope in infrared light, shows vast glowing fields of gas and dust, indicating that much of this dust is heated by forming stars.  The centers of some clouds, such as the snake-like structure on the upper left, are so thick and cold that they are dark even in infrared light. Many of the red dots are glowing dust shrouds centered on very young newly formed stars.  The unusual red sphere below the snake is actually a supernova remnant, the glowing shell of a young star so massive it evolved rapidly and exploded.  The region spans about 150 light years and lies about 10,000 light years away toward the constellation of Sagittarius.   APOD editor to review best space pictures in Philadelphia Wednesday night
Zodiacal Light and the False Dawn (2007-09-25)
An unusual triangle of light will be particularly bright near the eastern horizon before sunrise during the next two months for observers in Earth's northern hemisphere.  Once considered a false dawn, this triangle of light is actually Zodiacal Light, light reflected from interplanetary dust particles.  The triangle is clearly visible toward the left of the frame taken from the Paranal Observatory in Chile in July.  Zodiacal dust orbits the Sun predominantly in the same plane as the planets: the ecliptic.  Zodiacal light is so bright this time of year because the dust band is oriented nearly vertical at sunrise, so that the thick air near the horizon does not block out relatively bright reflecting dust.  Zodiacal light is also bright for people in Earth's northern hemisphere in March and April just after sunset.  APOD editor to review best space pictures in Philadelphia tomorrow (Wednesday) night
Saguaro Moon (2007-09-26)
A Full Moon rising can be a dramatic celestial sight, and Full Moons can have many names. For example, tonight's Full Moon, the one nearest the autumnal equinox in the northern hemisphere, is popularly called the Harvest Moon. According to lore the name is a fitting one because farmers could work late into the night at the end of the growing season harvesting crops by moonlight. In the same traditions, the Full Moon following the Harvest Moon is the Hunter's Moon. But, recorded on a trip to the American southwest, this contribution to compelling images of moonrise is appropriately titled Saguaro Moon.
Hole in the Sun (2007-09-27)
The dark expanse below the equator of the Sun is a coronal hole -- a low density region extending above the surface where the solar magnetic field opens freely into interplanetary space. Shown in false color, the picture was recorded on September 19th in extreme ultraviolet light by the EIT instrument onboard the space-based SOHO observatory. Studied extensively from space since the 1960s in ultraviolet and x-ray light, coronal holes are known to be the source of the high-speed solar wind, atoms and electrons that flow outward along the open magnetic field lines. The solar wind streaming from this coronal hole triggered colorful auroral displays on planet Earth begining late last week, enjoyed by spaceweather watchers at high latitudes.
A Hole in Mars Close Up (2007-09-28)
In a close-up from the HiRISE instrument onboard the Mars Reconnaissance Orbiter, this mysterious dark pit, about 150 meters across, lies on the north slope of ancient martian volcano Arsia Mons. Lacking raised rims and other impact crater characteristics, this pit and others like it were originally identified in visible light and infrared images from the Mars Odyssey and Mars Global Surveyor spacecraft. While the visible light images showed only darkness within, infrared thermal signatures indicated that the openings penetrated deep under the martian surface and perhaps were skylights to underground caverns. In this later image, the pit wall is partially illuminated by sunlight and seen to be nearly vertical, though the bottom, at least 78 meters below, is still not visible.  The dark martian pits are thought to be related to collapse pits in the lava flow, similar to Hawaiian volcano pit craters.
Dawn Launch Mosaic (2007-09-29)
Shortly after sunrise on Thursday at Cape Canaveral Air Force Station, the Dawn spacecraft began its journey to the asteroid belt, arcing eastward into a blue and cloudy sky. Dawn's voyage began on a conventional, chemically fueled Delta II rocket, but will continue with an innovative ion propulsion system. The spacecraft's extremely efficient ion engines will use electricity derived from solar power to ionize xenon atoms and generate a gentle but continuous thrust. After a four year interplanetary cruise, Dawn will orbit two small worlds, first Vesta and then Ceres. Vesta is one of the largest main belt asteroids, while nomenclature introduced by the International Astronomical Union in 2006 classifies nearly spherical Ceres as a dwarf planet.
A Milky Way Band (2007-09-30)
Most bright stars in our Milky Way Galaxy reside in a disk.  Since our Sun also resides in this disk, these stars appear to us as a diffuse band that circles the sky.  The above panorama of a northern band of the  Milky Way's disk covers 90 degrees and is a digitally created mosaic of several independent exposures.   Scrolling right will display the rest of this spectacular picture. Visible are many bright stars, dark dust lanes, red emission nebulae, blue reflection nebulae, and clusters of stars.  In addition to all this matter that we can see, astronomers suspect there exists even more dark matter that we cannot see.
The Small Cloud of Magellan (2007-10-01)
Portuguese navigator Ferdinand Magellan and his crew had plenty of time to study the southern sky during the first circumnavigation of planet Earth. As a result, two celestial wonders easily visible for southern hemisphere skygazers are known as the Clouds of Magellan. These cosmic clouds are now understood to be dwarf irregular galaxies, satellites of our larger spiral Milky Way Galaxy. The Small Magellanic Cloud pictured above actually spans 15,000 light-years or so and contains several hundred million stars. About 210,000 light-years distant in the constellation Tucana, it is the fourth closest of the Milky Way's known satellite galaxies, after the Canis Major and Sagittarius Dwarf galaxies and the Large Magellanic Cloud. This gorgeous view also includes two foreground globular star clusters NGC 362 (bottom right) and 47 Tucanae. Spectacular 47 Tucanae is a mere 13,000 light-years away and seen here to the left of the Small Magellanic Cloud.
Tutulemma: Solar Eclipse Analemma (2007-10-02)
If you went outside at exactly the same time every day and took a picture that included the Sun, how would the Sun appear to move?  With great planning and effort, such a series of images can be taken.   The figure-8 path the Sun follows over the course of a year is called an analemma.  With even greater planning and effort, the series can include a total eclipse of the Sun as one of the images. Pictured is such a total solar eclipse analemma or Tutulemma - a term coined by the photographers based on the Turkish word for eclipse. The composite image sequence was recorded from Turkey starting in 2005. The base image for the sequence is from the total phase of a solar eclipse as viewed from Side, Turkey on 2006 March 29. Venus was also visible during totality, toward the lower right.
Comet Encke's Tail Ripped Off (2007-10-03)
Swinging inside the orbit of Mercury, on April 20th periodic comet Encke encountered a blast from the Sun in the form of a Coronal Mass Ejection (CME). When CMEs, enormous clouds of energetic particles ejected from the Sun, slam into Earth's magnetosphere, they often trigger auroral displays. But in this case, the collison carried the tail of the comet away. The tail was likely ripped off by interacting magnetic fields rather than the mechanical pressure of the collision. Clicking on the two panel image will play a movie gif of the remarkable event as recorded by the Heliospheric Imager onboard the STEREO A spacecraft. In the movie, the time between frames is about 45 minutes, while the frames span about 14x20 million kilometers at the distance of the comet. Of course, similar collisions have happened before as the ancient comet loops through its 3.3 year solar orbit. So don't worry, Encke's tail grows back!
50th Anniversary of Sputnik: Traveling Companion (2007-10-04)
Sputnik means "traveling companion". Despite the innocuous sounding name, the launch of planet Earth's first artificial moon, Sputnik 1, by the Soviet Union on October 4, 1957, changed the world and set in motion events which resulted in the creation of NASA and the race to the Moon. Sputnik 1 was a 184 pound, 22 inch diameter sphere with four whip antennas connected to battery powered transmitters. The transmitters broadcast a continuous "beeping" signal to an astounded earthbound audience for 23 days. A short month later, on November 3, the Soviet Union followed this success by launching a dog into orbit aboard Sputnik 2.
Starburst Cluster in NGC 3603 (2007-10-05)
A mere 20,000 light-years from the Sun lies NGC 3603, a resident of the nearby Carina spiral arm of our Milky Way Galaxy. NGC 3603 is well known to astronomers as one of the Milky Way's largest star-forming regions. The central open star cluster contains thousands of stars more massive than our Sun, stars that likely formed only one or two million years ago in a single burst of star formation. In fact, nearby NGC 3603 is thought to contain a convenient example of the massive star clusters that populate much more distant starburst galaxies. Surrounding the cluster are natal clouds of glowing interstellar gas and obscuring dust, sculpted by energetic stellar radiation and winds. Recorded by the Hubble's Advanced Camera for Surveys, the image spans about 17 light-years.
X-ray Stars of Orion (2007-10-06)
The stars of Orion shine brightly in visible light in planet Earth's night sky. The constellation harbors the closest large stellar nursery, the Great Nebula of Orion, a mere 1,500 light-years away. In fact, the apparently bright clump of stars near the center of this false color Chandra x-ray telescope picture are the massive stars of the Trapezium - the young star cluster which powers much of the nebula's visible-light glow. The stars shown in blue and orange are young sun-like stars; prodigious sources of x-rays thought to be produced in hot stellar coronae and surface flares in a young star's strong magnetic field. Our middle-aged Sun itself was probably thousands of times brighter in x-rays when, like the Trapezium stars, it was only a few million years old. The x-ray image spans about 2.5 light-years across the central region of the Orion Nebula.
Two Million Galaxies (2007-10-07)
Our universe is filled with galaxies.  Galaxies -- huge conglomerations of stars, gas, dust -- and mysterious  dark matter are the basic building blocks of the large-scale universe.   Although distant galaxies move away from each other as the universe expands, gravity attracts neighboring galaxies to each other, forming galaxy groups, clusters of galaxies, and even larger expansive filaments.  Some of these structures are visible on one of the most comprehensive maps of the sky ever made in galaxies: the APM galaxy survey map completed in the early 1990s.  Over 2 million galaxies are depicted above in a region 100 degrees across centered toward our Milky Way Galaxy's south pole.  Bright regions indicate more galaxies, while bluer colors denote larger average galaxies.  Dark ellipses have been cut away where bright local stars dominate the sky.  Many scientific discoveries resulted from analyses of the map data, including that the universe was surprisingly complex on large scales.
Galaxy NGC 474: Cosmic Blender (2007-10-08)
What's happening to galaxy NGC 474? The multiple layers of emission appear strangely complex and unexpected given the relatively featureless appearance of the elliptical galaxy in less deep images.  The cause of the shells is currently unknown, but possibly tidal tails related to debris left over from absorbing numerous small galaxies in the past billion years.  Alternatively the shells may be like ripples in a pond, where the ongoing collision with the spiral galaxy to the right of NGC 474 is causing density waves to ripple though the galactic giant.  Regardless of the actual cause, the above image dramatically highlights the increasing consensus that the outer halos of most large galaxies are not really smooth but have complexities induced by frequent interactions with -- and accretions of -- smaller nearby galaxies.  The halo of our own Milky Way Galaxy is one example of such unexpected complexity. NGC 474 spans about 250,000 light years and lies about 100 million light years distant toward the constellation of the Fish Pisces.
Aurora, Stars, Meteor, Lake, Alaska (2007-10-09)
Sometimes, after your eyes adapt to the dark, a spectacular sky appears. In this case, a picturesque lake lies in front of you, beautiful green aurora flap high above you, brilliant stars shine far in the distance, and, for a brief moment, a bright meteor streaks by.  This digitally fused breathtaking panorama was captured late last month across one of the Chena Lakes in North Pole, Alaska, USA, and includes the Pleiades open cluster of stars on the image right.  The shot is unusual not only for the many wonders it has captured simultaneously, but because lakes this far north tend to freeze and become non-reflecting before a sky this dark can be photographed.
The Strange Trailing Side of Saturn's Iapetus (2007-10-10)
What has happened to Saturn's moon Iapetus?  Vast sections of this strange world are dark as coal, while others are as bright as ice.  The composition of the dark material is unknown, but infrared spectra indicate that it possibly contains some dark form of carbon.  Iapetus also has an unusual equatorial ridge that makes it appear like a walnut.  To help better understand this mysterious moon, NASA directed the robotic Cassini spacecraft orbiting Saturn to swoop within 2,000 kilometers just last month. Pictured above, from about 75,000 kilometers out, Cassini's trajectory allowed unprecedented imaging of the hemisphere of Iapetus that is always trailing.  A huge impact crater seen in the south spans a tremendous 450 kilometers and appears superposed on an older crater of similar size. The dark material is seen increasingly coating the easternmost part of Iapetus, darkening craters and highlands alike.  Close inspection indicates that the dark coating typically faces the moon's equator.  Whether Iapetus' colors are the result of unusual episodes of internal volcanism or external splattering remains unknown.  This and other images from Cassini's Iapetus flyby are being studied for even greater clues.
Bright Planets, Crescent Moon (2007-10-11)
rly risers are currently enjoying the sight of dazzling Venus, near the eastern horizon as the morning star. Recorded on October 7, this predawn skyview does feature Venus at the upper right. It also includes a crescent Moon and Saturn (lower left). In fact, holding your fist at arms length would have easily covered both planets and the Moon in this 5 degree wide field. Earthshine, sunlight reflected from planet Earth's dayside, illuminates features on the lunar nightside. A close inspection of Saturn itself reveals a nearby pinpoint of light corresponding to Saturn's large moon Titan. Though the Moon has moved on, the tight triangle formed by Venus, Saturn, and Regulus (top), alpha star in the constellation Leo, will continue to look impressive in early morning skies over the next few days. Early bird astrophotographer Jay Ouellet also described Mars as a "brilliant red diode" in his dark country sky east of Quebec City, Canada.   Count the Stars: The Great World Wide Star Count
The Whale and The Hockey Stick (2007-10-12)
NGC 4631 is a big beautiful spiral galaxy seen edge-on (top right) only 25 million light-years away towards the small northern constellation Canes Venatici. This galaxy's slightly distorted wedge shape suggests to some a cosmic herring and to others the popular moniker of The Whale Galaxy. Either way, it is similar in size to our own Milky Way. In this gorgeous color image, the Whale's dark interstellar dust clouds, yellowish core, and young blue star clusters are easy to spot. A companion galaxy, the small elliptical NGC 4627, appears above the Whale Galaxy. At the lower left is another distorted galaxy, the hockey stick-shaped NGC 4656. The distortions and mingling trails of gas detected at other wavelengths suggest that all three galaxies have had close encounters with each other in their past. The Whale Galaxy is also known to have spouted a halo of hot gas glowing in x-rays.   Count the Stars: The Great World Wide Star Count
Enceladus Ice Geysers (2007-10-13)
Ice geysers erupt on Enceladus, bright and shiny inner moon of Saturn. Shown in this false-color image, a backlit view of the moon's southern limb, the majestic, icy plumes were discovered by instruments on the Cassini Spacecraft during close encounters with Enceladus in November of 2005. Eight source locations for these geysers have now been identified along substantial surface fractures in the moon's south polar region. Researchers suspect the geysers arise from near-surface pockets of liquid water with temperatures near 273 kelvins (0 degrees C). That's hot when compared to the distant moon's surface temperature of 73 kelvins (-200 degrees C).  The cryovolcanism is a dramatic sign that tiny, 500km-diameter Enceladus is surprisingly active. Enceladus ice geysers also likely produce Saturn's faint but extended E ring.
NGC 3132: The Eight Burst Nebula (2007-10-14)
It's the dim star, not the bright one, near the center of NGC 3132 that created this odd but beautiful planetary nebula.  Nicknamed the Eight-Burst Nebula and the Southern Ring Nebula, the glowing gas originated in the outer layers of a star like our Sun.  In this representative color picture, the hot blue pool of light seen surrounding this binary system is energized by the hot surface of the faint star.  Although photographed to explore unusual symmetries, it's the asymmetries that help make this planetary nebula so intriguing.  Neither the unusual shape of the surrounding cooler shell nor the structure and placements of the cool filamentary dust lanes running across NGC 3132 are well understood.
Jupiter's Clouds from New Horizons (2007-10-15)
The New Horizons spacecraft took some stunning images of Jupiter earlier this year while on the way out to Pluto. Famous for its Great Red Spot, Jupiter is also known for its regular, equatorial cloud bands, visible through even modest sized telescopes. The above image was taken near Jupiter's terminator, and shows that the Jovian giant possibly has the widest diversity of cloud patterns in our Solar System.  On the far left are clouds closest to Jupiter's south pole.  Here turbulent whirlpools and swirls are seen in a dark region, dubbed a belt, that rings the planet.  Even light colored regions, called zones, show tremendous structure, complete with complex wave patterns.   The energy that drives these waves likely comes from below.  New Horizons is the fastest space probe ever launched, and is zipping through the Solar System on track to reach Pluto in 2015.
SN 2005ap: The Brightest Supernova Yet Found (2007-10-16)
What could cause a bang this big?  This supernova explosion was so inherently bright that it could be seen nearly 5 billion light years away (a redshift of 0.28) even with a small telescope. Specific colors emitted during SN 2005ap indicate that it was a Type II supernova, a breed of stellar explosion that results when a high mass star begins fusing heavy elements in or near its core.  Type II supernovas may be more powerful than their Type Ia cousins, but they are not currently more useful cosmologically because astronomers don't understand how to accurately recover their intrinsic brightnesses.  It is therefore dimmer Type Ia supernovas that are used by astronomers to calibrate the distance scale of the nearby universe.  Were Type II supernova better understood, astronomers might be able to probe distances further into the universe, and so probe the stability of the strange dark energy that dominates the present universe. Pictured above in a digitally compressed image, the bright supernova SN 2005ap is visible on the right where no exploding star had been seen on the left less than three months before.
I Zwicky 18: The Case of the Aging Galaxy (2007-10-17)
How old is this galaxy?  The galaxy on the left, I Zwicky 18, was once thought to be one of the youngest galaxies on record since its bright stars indicated an age of only 500 million years.  The galaxy was also intriguing because it resembled galaxies forming in the very early universe, but mysterious since it is so nearby -- only 59 million light years away -- and surrounded by galaxies that are significantly older.  Recent images of I Zwicky 18 by the Hubble Space Telescope have helped resolve this mystery, discovering a population of old faint stars intermixed with the bright star population. Therefore I Zwicky 18 is now thought to be just as old as its neighbors, roughly 10 billion years old, but with an intense episode of relative new star formation. Possibly the trigger for this recent episode of bright star formation is the changing gravitational influence of  I Zwicky 18's smaller companion galaxy, visible at the upper right.
The Elephant's Trunk in IC 1396 (2007-10-18)
Like an illustration in a galactic Just So Story, the Elephant's Trunk Nebula winds through the emission nebula and young star cluster complex IC 1396, in the high and far off constellation of Cepheus. Of course, this cosmic elephant's trunk is over 20 light-years long. The false-color view was recorded through narrow band filters that transmit the light from hydrogen (in green), sulfur (in red), and oxygen (in blue) atoms in the region. The resulting composite highlights the bright swept-back ridges that outline pockets of cool interstellar dust and gas. Such embedded, dark, tendril-shaped clouds contain the raw material for star formation and hide protostars within the obscuring cosmic dust. Nearly 3,000 light-years distant, the relatively faint IC 1396 complex covers a large region on the sky, spanning about 5 degrees. This dramatic close-up covers a 1/2 degree wide field, about the size of the Full Moon.
IC 5067 in the Pelican Nebula (2007-10-19)
The prominent ridge of emission featured in this dramatic 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.   A new APOD RSS feed is available here, or from the link line below.