omnianasa/nasa-apod-metadata huggingface dataset:
SN 2006GY: Brightest Supernova (2007-05-10)
The stellar explosion cataloged as supernova SN 2006gy shines in this wide-field image (left) of its host galaxy, NGC 1260, and expanded view (upper right panel) of the region surrounding the galaxy's core. In fact, given its estimated distance of 240 million light-years, SN 2006gy was brighter than, and has stayed brighter longer than, any previously seen supernova. The Chandra observations in the lower right panel establish the supernova's x-ray brightness and lend strong evidence to the theory that SN 2006gy was the death explosion of a star well over 100 times as massive as the Sun. In such an exceptionally massive star, astronomers suspect an instability producing matter-antimatter pairs led to the cosmic blast and obliterated the stellar core. Thus, unlike in other massive star supernovae, neither neutron star, or even black hole, would remain. Intriguingly, analogs in our own galaxy for SN 2006gy's progenitor may include the well-known, extremely massive star Eta Carinae.
LDN 1622: Dark Nebula in Orion (2007-05-11)
The silhouette of an intriguing dark nebula inhabits this cosmic scene, based on images from the Palomar Observatory Sky Survey. Lynds' Dark Nebula (LDN) 1622 appears against a faint background of glowing hydrogen gas only easily seen in long telescopic exposures of the region. LDN 1622 lies near the plane of our Milky Way Galaxy, close on the sky to Barnard's Loop - a large cloud surrounding the rich complex of emission nebulae found in the Belt and Sword of Orion. But the obscuring dust of LDN 1622 is thought to be much closer than Orion's more famous nebulae, perhaps only 500 light-years away. At that distance, this 1 degree wide field of view would span less than 10 light-years.
HD 189733b: Hot Jupiter (2007-05-12)
HD 189733b is a Jupiter-sized planet known to orbit a star some 63 light-years away. But while the distant world is approximately the size of Jupiter, its close-in orbit makes it much hotter than our solar system's ruling gas giant. Like other detected hot Jupiters, its rotation is tidally locked -- one side always faces its parent star as it orbits once every 2.2 days. Using infrared data from the Spitzer Space Telescope, this planet's temperature variations have been mapped out -- the first map ever made for a planet beyond our solar system. Seen here (brighter colors = higher temperatures), the hottest spot on the planet is not at longitude 0.0, the point exactly facing the parent star. Instead, it's about 30 degrees to the east (right), evidence that fierce, planet circling winds influence the temperature. In the planet-wide map, the temperature measurements vary from about 930 to 650 degrees C (1,700 to 1,200 F).
The Cat's Eye Nebula from Hubble (2007-05-13)
Staring across interstellar space, the alluring Cat's Eye nebula lies three thousand light-years from Earth. A classic planetary nebula, the Cat's Eye (NGC 6543) represents a final, brief yet glorious phase in the life of a sun-like star. This nebula's dying central star may have produced the simple, outer pattern of dusty concentric shells by shrugging off outer layers in a series of regular convulsions. But the formation of the beautiful, more complex inner structures is not well understood. Seen so clearly in this sharp Hubble Space Telescope image, the truly cosmic eye is over half a light-year across.  Of course, gazing into the Cat's Eye, astronomers may well be seeing the fate of our sun, destined to enter its own planetary nebula phase of evolution ... in about 5 billion years.
Rotating Earth from Galileo (2007-05-14)
When passing Earth on your way to Jupiter, what should you look for? That question arose for the robotic Galileo spacecraft that soundlessly coasted past the Solar System's most photographed orb almost two decades ago.  The Galileo spacecraft, although originally launched from Earth, coasted past its home world twice in an effort to gain speed and shorten the duration of its trip to Jupiter.  During Galileo's first Earth flyby in late 1990, it made a majestically silent home movie of our big blue marble rotating by taking images almost every minute during a 25-hour period.  The above picture is one frame from this movie -- clicking on this frame will put it in motion (in many browsers).  Visible on Earth are vast blue oceans, swirling white clouds, large golden continents, and even one continent frozen into a white sheet of water-ice.  As Galileo passed, it saw a globe that not only rotated but began to recede into the distance.  Galileo went on to a historic mission uncovering many secrets and mysteries of Jupiter over the next 14 years, before performing a final spectacular dive into the Jovian atmosphere.
Bright Spiral Galaxy M81 in Ultraviolet from Galex (2007-05-15)
Where are the hot stars in M81, one of the closest major spiral galaxies? To help find out, astronomers took a deep image in ultraviolet light of the sprawling spiral with the Earth-orbiting Galex telescope.  Hot stars emit more ultraviolet than cool stars, and are frequently associated with young open clusters of stars and energetic star forming regions.  Magnificent spiral galaxy M81, slightly smaller in size to our own Milky Way Galaxy, shows off its young stars in its winding spiral arms in the above image.  Less than 100 million years old, the young stars are blue in the above false-color Galex image and seen to be well separated from the older yellowish stars of the galactic core. Visible above M81 is a satellite galaxy dubbed Holmberg IX.   Studying the unexpectedly bright ultraviolet glow of this small irregular galaxy may help astronomers understand how the many satellites of our own Milky Way Galaxy developed.  M81, visible through a small telescope, spans about 70,000 light years and lies about 12 million light years away toward the constellation of the Great Bear (Ursa Major).
Dark Matter Ring Modeled around Galaxy Cluster CL0024+17 (2007-05-16)
How do we know that dark matter isn't just normal matter exhibiting strange gravity?  A new observation of gravitationally magnified faint galaxies far in the distance behind a massive cluster of galaxies is shedding new dark on the subject.   The above detailed image from the Hubble Space Telescope indicates that a huge ring of dark matter likely exists surrounding the center of CL0024+17 that has no normal matter counterpart.  What is visible in the above image, first and foremost, are many spectacular galaxies that are part of CL0024+17 itself, typically appearing tan in color.  Next, a close inspection of the cluster center shows several unusual and repeated galaxy shapes, typically more blue.  These are multiple images of a few distant galaxies, showing that the cluster is a strong gravitational lens.  It is the relatively weak distortions of the many distant faint blue galaxies all over the image, however, that indicates the existence of the dark matter ring. The computationally modeled dark matter ring spans about five million light years and been digitally superimposed to the image in diffuse blue.  A hypothesis for the formation of the huge dark matter ring holds that it is a transient feature formed when galaxy cluster CL0024+17 collided with another cluster of galaxies about one billion years ago, leaving a ring similar to when a rock is thrown in a pond.
The Milky Way Near the Southern Cross (2007-05-17)
The glow of the southern Milky Way and the well-known Southern Cross are featured in this colorful skyscape recorded in April over La Frontera, Chile. The Southern Cross (Crux) itself is at the right of the 20 degree wide field of view, topped by bright, yellowish star Gamma Crucis. A line from Gamma Crucis through the blue star at the bottom of the cross, Alpha Crucis, points toward the south celestial pole. Against faint Milky Way starlight, the dark expanse of the Coal Sack Nebula lies just left of the cross, while farther left along the Milky Way are the bright stars Hadar and Rigil Kentaurus, also known as Beta and Alpha Centauri. Blazing in the lower left, Alpha Cen is the closest star to the Sun, a mere 4.3 light-years distant. In fact, yellowish Alpha Cen is actually a triple star system that includes a sun-like star. Seen from Alpha Cen, our own Sun would be a bright yellowish star in the otherwise recognizable constellation Cassiopeia.
M13: The Great Globular Cluster in Hercules (2007-05-18)
In 1714, Edmond Halley noted that M13 "shows itself to the naked eye when the sky is serene and the Moon absent." Of course, M13 is now modestly recognized as the Great Globular Cluster in Hercules, one of the brightest globular star clusters in the northern sky. Telescopic views reveal the spectacular cluster's hundreds of thousands of stars. At a distance of 25,000 light-years, the cluster stars crowd into a region 150 light-years in diameter, but approaching the cluster core upwards of 100 stars could be contained in a cube just 3 light-years on a side. For comparison, the closest star to the Sun is over 4 light-years away. Along with the cluster's dense core, the outer reaches of M13 are highlighted in this deep color image. A distant background galaxy, NGC 6207 is also visible above and to the right of the Great Globular Cluster M13.
Circum-axial Leaf Trails (2007-05-19)
Are photographs of star trails really evidence of the Earth's rotation about its axis? Yes they are, and science journalist Trudy E. Bell discovered that there is a simple way to demonstrate this, if you have the stomach for it.  First, find a playground equipped with a standard Merry-Go-Round (MGR) located under or near a large, leafy tree. Seat yourself near the middle of the MGR platform. Ask a local playground expert (KID) to get you spinning very, very fast. As the scenery flashes by at a dizzying rate, point your camera skyward and take a picture with a slow shutter speed setting. The result will be similar to this excellent image of concentric, arcing leaf trails centered at a point corresponding to the MGR's axis of rotation - a convincing imitation of circumpolar star trails recorded in hours-long exposures of planet Earth's night sky. Then, just stand up and walk away ... if you still can.
A Spherule from the Earth's Moon (2007-05-20)
How did this spherule come to be on the Moon? When a meteorite strikes the Moon, the energy of the impact melts some of the splattering rock, a fraction of which might cool into tiny glass beads.  Many of these glass beads were present in lunar soil samples returned to Earth by the Apollo missions.  Pictured above is one such glass spherule that measures only a quarter of a millimeter across.  This spherule is particularly interesting because it has been victim to an even smaller impact.  A miniature crater is visible on the upper left, surrounded by a fragmented area caused by the shockwaves of the small impact.  By dating many of these impacts, astronomers can estimate the history of cratering on our Moon.
In the Center of Reflection Nebula NGC 1333 (2007-05-21)
The dust is so thick in the center of NGC 1333 that you can hardly see the stars forming.  Conversely, the very dust clouds that hide the stars also reflects their optical light, giving NGC 1333's predominantly blue glow the general designation of a reflection nebula. A highly detailed image of the nebula, shown above, was taken recently by the Mayall 4-meter telescope on Kitt Peak in Arizona, USA and released to honor astronomer Stephen Strom on his retirement. Visible near the image top are vast blue regions of dust predominantly reflecting the light from bright massive stars.  Visible in the thick central dust are not only newly formed stars but red jets and red-glowing gas energized by the light and winds from recently formed young stars.   The NGC 1333 nebula contains hundreds of newly formed stars that are less than one million years old. Reflection nebula NGC 1333 lies about 1,000 light years away toward the constellation of Perseus.
Venus Near the Moon (2007-05-23)
The two brightest objects in the night sky appeared to go right past each other last week.  On the night of May 19, Earth's Moon and the planet Venus were visible in the same part of the sky, and at closest approach were less than one degree apart.  The conjunction was captured in the above image taken from near Quebec City, Quebec, Canada.  Venus appears on the lower left of the above photo.  The spires that appear to emanate from Venus are diffraction spikes caused by the camera itself.   The image is so clear that craters on the Moon are resolved.  Of course, the real physical distance between the two heavenly bodies was not unusually small -- the apparent conjunction was really just an illusion of perspective. Although Earth's Moon passes Venus once each month, such a close passing visible in the evening sky is more rare.
The Tulip in the Swan (2007-05-24)
This expansive (1-degree wide) telescopic view looks out along the plane of our Milky Way Galaxy toward the nebula rich constellation Cygnus the Swan. It is centered on a bright hydrogen emission region recorded in the 1959 catalog by astronomer Stewart Sharpless as Sh2-101. About 8,000 light-years distant the nebula is popularly known as the Tulip Nebula, understandably not the only cosmic cloud to evoke the imagery of flowers. Complex and beautiful in visible light, the area also includes one of the brightest, most famous sources in the x-ray sky, Cygnus X-1. Discovered in the early 1970s, Cygnus X-1 is a bizarre binary system consisting of a massive, hot, supergiant star (seen here) in close orbit with a stellar mass black hole. The Cygnus X-1 system is also estimated to lie a comfortable 8,000 light-years away.
Jupiter, Vesta, and the Milky Way (2007-05-25)
In this gorgeous skyscape, gas giant Jupiter along with the stars and cosmic dust clouds of the Milky Way hang over the southern horizon in the early morning hours as seen from Stagecoach, Colorado, USA. Recorded on Thursday, Jupiter is the brightest object near picture center. Along with the stunning Milky Way, Jupiter is hard to miss, but a careful inspection of the view also reveals main belt asteroid Vesta. Of all the asteroids Vesta is the brightest and is now just bright enough to be visible to the naked eye from locations with very dark, clear skies. Vesta (as well as Jupiter) appears relatively bright now because it is near opposition, literally opposite the Sun in planet Earth's sky and closest to Earth in its orbit. For Vesta, this opposition offers the best viewing in many years. The year 2007 also coincides with the 200th anniversary of the asteroid's discovery. Starting late next month, NASA plans to launch the Dawn mission intended to explore Vesta (and Ceres) and the main asteroid belt.
The Moon's Saturn (2007-05-26)
On May 22nd, just days after sharing the western evening sky with Venus, the Moon moved on to Saturn - actually passing in front of the ringed planet when viewed in skies over Europe, northern Africa, and western Asia. Because the Moon and bright planets wander through the sky near the ecliptic plane, such occultation events are not uncommon, but they are dramatic, especially in telescopic views. For example, in this sharp image Saturn is captured emerging from behind the Moon, giving the illusion that it lies just beyond the Moon's bright edge. Of course, the Moon is a mere 400 thousand kilometers away, compared to Saturn's distance of 1.4 billion kilometers. Taken with a digital camera and 20 inch diameter telescope at the Weikersheim Observatory in southern Germany, the picture is a single exposure adjusted to reduce the difference in brightness between Saturn and the cratered lunar surface.
The Horsehead Nebula (2007-05-27)
One of the most identifiable nebulae in the sky, the Horsehead Nebula in Orion, is part of a large, dark, molecular cloud.  Also known as Barnard 33, the unusual shape was first discovered on a photographic plate in the late 1800s.  The red glow originates from hydrogen gas predominantly behind the nebula, ionized by the nearby bright star Sigma Orionis.  The darkness of the Horsehead is caused mostly by thick dust, although the lower part of the Horsehead's neck casts a shadow to the left.  Streams of gas leaving the nebula are funneled by a strong magnetic field.  Bright spots in the Horsehead Nebula's base are young stars just in the process of forming.  Light takes about 1500 years to reach us from the Horsehead Nebula.   The above image was taken with the 0.9-meter telescope at  Kitt Peak National Observatory.
A Hole in Mars (2007-05-28)
Black spots have been discovered on Mars that are so dark that nothing inside can be seen. Quite possibly, the spots are entrances to deep underground caves capable of protecting Martian life, were it to exist.  The unusual hole pictured above was found on the slopes of the giant Martian volcano Arsia Mons. The above image was captured three weeks ago by the HiRISE instrument onboard the Mars Reconnaissance Orbiter currently circling Mars.  The holes were originally identified on lower resolution images from the Mars Odyssey spacecraft, The above hole is about the size of a football field and is so deep that it is completely unilluminated by the Sun.  Such holes and underground caves might be prime targets for future spacecraft, robots, and even the next generation of human interplanetary explorers.
Bright Spiral Galaxy M81 from Hubble (2007-05-29)
The Hubble Space Telescope has resolved individual stars in a spectacular new image of nearby spiral galaxy M81.  The feat is similar to Edwin Hubble's historic images with the Mt. Wilson 100-inch Hooker Telescope in the 1920s that resolved stars in neighboring galaxy M31.  Edwin Hubble was able to use individual Cepheid variable stars to show that M31 was not nearby swirling gas but rather an entire galaxy like our Milky Way Galaxy.   This above image in visible light taken by the Hubble Space Telescope is being used in conjunction with images being taken in ultraviolet by Galex, infrared by Spitzer, and X-rays with Chandra to study how stars have formed and died over the history M81.  Light takes about 12 million years to reach us from M81.  M81 is visible with binoculars toward the constellation of the Great Bear (Ursa Major).
Liquid Sea on Saturn's Titan (2007-05-30)
What is this vast dark region on Titan?  Quite possible a sea of liquid hydrocarbons. The region was imaged earlier this month when the robotic Cassini spacecraft swooped past Saturn's cloudy moon and illuminated part of it with radar.  The dark region in the above image reflected little radar, an effect expected were the dark surface relatively flat, as expected for a liquid.   Other indications that the vast dark area is liquid include the coastline-like topology of the brighter regions, which appear to include islands, inlets, and tributary channels. The uninterrupted smoothness of much of the dark sea may indicate that the sea runs deep, with speculation holding a depth estimate of tens of meters. A hydrocarbon sea on Titan holds particular interest for exobiologists as it might be a place where life could develop.  In 2005 the Huygens probe landed on Titan and returned the first surface images.  Cassini will continue to explore Titan, as 13 more flybys are planned.
Dwarf Galaxies in the Coma Cluster (2007-05-31)
In visible light images, over a thousand galaxies are seen to lie within a volume about 20 million light-years across in the rich Coma Galaxy Cluster. But infrared images of the Coma Cluster have now been used to add thousands more to the Coma's galaxy count in the form of previously undiscovered dwarf galaxies. This composite combines infrared Spitzer Space Telescope image data (red and green) with visible light Sloan Sky Survey data (blue) for the central part of the cluster. Over 1 degree wide, the field is dominated by two giant elliptical galaxies in blue. Still, many of the small green smudges (see magnified inset) are identified as dwarf galaxies, roughly comparable to the Small Magellanic Cloud. Dwarf galaxies are thought to form first, providing building blocks for larger galaxies. The well-studied, friendly, Coma Cluster is 320 million light-years away.
Messier 65 (2007-06-01)
M65 is a big, beautiful spiral galaxy, the sixty-fifth object in the famous astronomical catalog compiled by 18th century cosmic tourist Charles Messier. It's also a member of a picturesque trio of large spiral galaxies known as the Leo Triplet, about 35 million light-years away. This sharp view of M65 shows off the galaxy in remarkable detail, with tightly wound spiral arms and dust lanes stretching into a core dominated by the yellowish light from an older population of stars.  In fact, M65 seems to be the least disturbed of the Leo Trio, though it is close enough to be interacting gravitationally with the other two galaxies (not seen here). Very nearly edge-on to our line-of-sight, M65 is about 100,000 light-years across, similar in size to our Milky Way Galaxy.
3D Full Moon (2007-06-02)
Get out your red/blue glasses and check out this satisfying stereo anaglyph of the Full Moon. A corresponding stereo image pair, intended for cross-eyed viewing, is also available through this link. Regardless of your preferred technique for stereo viewing, the 3D effect comes from combining pictures of the same scene taken at different angles -- mimicking the slightly different perspective of each eye. Perhaps surprisingly for Earthdwellers, getting two pictures of the Full Moon from different angles only requires a little patience. In this case, photographer Laurent Laveder used pictures taken months apart, one in November 2006 and one in January 2007. He relied on the Moon's continuous libration or wobble as it orbits to produce two shifted images of a Full Moon.
Shuttle Plume Shadow Points to Moon (2007-06-03)
Why would the shadow of a space shuttle launch plume point toward the Moon? In early 2001 during a launch of Atlantis, the Sun, Earth, Moon, and rocket were all properly aligned for this photogenic coincidence.  First, for the space shuttle's plume to cast a long shadow, the time of day must be either near sunrise or sunset.  Next, just at sunset, the shadow is the longest and extends all the way to the horizon.  Finally, during a Full Moon, the Sun and Moon are on opposite sides of the sky.  Just after sunset, for example, the Sun is slightly below the horizon, and, in the other direction, the Moon is slightly above the horizon.  Therefore, as Atlantis blasted off, just after sunset, its shadow projected away from the Sun toward the opposite horizon, where the Full Moon just happened to be.
IC 4603: Reflection Nebula in Ophiuchius (2007-06-04)
Why does this starfield photograph resemble an impressionistic painting?  The effect is created not by digital trickery but by large amounts of interstellar dust.  Dust, minute globs rich in carbon and similar in size to cigarette smoke, frequently starts in the outer atmospheres of large, cool, young stars. The dust is dispersed as the star dies and grows as things stick to it in the interstellar medium.  Dense dust clouds are opaque to visible light and can completely hide background stars.  For less dense clouds, the capacity of dust to preferentially reflect blue starlight becomes important, effectively blooming the stars blue light out and marking the surrounding dust.  Nebular gas emissions, typically brightest in red light, can combine to form areas seemingly created on an artist's canvas.  Photographed above is roughly four square degrees of the nebula IC 4603 near the bright star Antares toward the constellation of Ophiuchus.