omnianasa/nasa-apod-metadata huggingface dataset:
The Deep Field
Credit: (1997-02-09)
Galaxies like colorful pieces of candy fill the Hubble Deep Field - humanity's most distant yet optical view of the Universe. The dimmest, some as faint as 30th magnitude (about four billion times fainter than stars visible to the unaided eye), are the most distant galaxies and represent what the Universe looked like in the extreme past, perhaps less than one billion years after the Big Bang. To make the Deep Field image, astronomers selected an uncluttered area of the sky in the constellation Ursa Major (the Big Bear) and pointed the Hubble Space Telescope at a single spot for 10 days accumulating and combining many separate exposures. With each additional exposure, fainter objects were revealed. The final result can be used to explore the mysteries of galaxy evolution and the infant Universe.
The Gamma Ray Moon
Credit: (1997-02-10)
What if you could see gamma rays (photons with more than 40 million times the energy of visible light)? If you could, the Moon would appear brighter than the Sun! This startling notion is demonstrated by this image of the Moon from the Energetic Gamma Ray Experiment Telescope (EGRET) onboard NASA's orbiting Compton Gamma Ray Observatory. The most sensitive instrument of its kind, even EGRET can not see the quiet Sun which is faint at extreme gamma-ray energies. Why is the Moon so bright in gamma rays? High energy charged particles known as cosmic rays, constantly bombard the unprotected lunar surface generating gamma rays. EGRET's gamma-ray vision is not sharp enough to resolve a lunar disk or any surface features but its sensitivity reveals the bright gamma-ray moonglow against a background of gamma rays from our Milky Way galaxy, gamma-ray quasars and some still mysterious unidentified sources. The image was generated from eight exposures made during 1991-1994. A wide-angle picture, it covers a roughly 40x40 degree field of view with gamma-ray intensity represented in false color.
Space Walz
Credit: (1997-02-11)
Astronaut Carl Walz waves at his colleagues from the aft end of the Space Shuttle Discovery's payload bay - during a 1993 spacewalk to evaluate tools, tethers, and a foot restraint slated for use in the first Hubble Space Telescope servicing mission. Today's successful launch of Discovery begins the second servicing mission to the Hubble. Discovery's crew will rendezvous with the orbiting telescope and capture it with the shuttle's manipulator arm. With Hubble in the payload bay the crew will conduct spacewalks to replace two existing instruments with new ones. To be installed are the Space Telescope Imaging Spectrograph and the Near Infrared Camera and Multi-Object Spectrometer. Other hardware will also be replaced and upgraded including the telescope's Fine Guidance Sensor. The improved instrumentation will extend the Hubble's ability to explore the distant Universe.
Comet Hale-Bopp Develops a Tail (1997-02-12)
Comet Hale-Bopp has quite a tail to tell already. This remarkable comet was first discovered in 1995, even before Comet Hyakutake. Since then, this erupting snowball continues to fall into our inner Solar System and is starting to put on quite a show. Comets have been known throughout history to show tails that spread across the sky.  In the above picture, the blue stream is the ion tail which consists of ions pushed away from the comet's head by the solar wind. The ion tail always points directly away from the Sun. Comet Hale-Bopp is now visible in the morning sky, moving a few degrees each day. Comet Hale-Bopp is expected to be at its best and brightest in late March and early April.
More Jets From Comet Hale-Bopp
Credit: (1997-02-13)
Comets become fountains of gas and dust as they get near the Sun. Solar heat vaporizes the outer layers of these spectacular orbiting icebergs, exposing caverns of pressurized gas that erupt into jets. The above digitally enhanced image of Comet Hale-Bopp was taken on January 29th and highlights several of these dust jets.  Here, background stars appear as faint raised streaks. Comet Hale-Bopp is currently brighter than most stars, and is visible in the morning sky. Comet Hale-Bopp will continue to brighten and develop an extended tail until April.
NGC 1818: A Young Globular Cluster
Credit: (1997-02-14)
Globular clusters once ruled the Milky Way. Back in the old days, back when our Galaxy first formed, perhaps thousands of globular clusters roamed our Galaxy. Today, there are perhaps 200 left. Many globular clusters were destroyed over the eons by repeated fateful encounters with each other or the Galactic center. Surviving relics are older than any earth fossil, older than any other structures in our Galaxy, and limit the universe itself in raw age. There are few, if any, young globular clusters in our Milky Way Galaxy because conditions are not ripe for more to form. But things are different next door - in the neighboring LMC galaxy. Pictured above is a "young" globular cluster residing there: NGC 1818. Recent observations show it formed only about 40 million years ago - just yesterday compared to the 12 billion year ages of globular clusters in our own Milky Way
Shapley 1: An Annular Planetary Nebula
Credit and Copyright: (1997-02-15)
What happens when a star runs out of nuclear fuel? The center condenses into a white dwarf while the outer atmospheric layers are expelled into space and appear as a planetary nebula. This particular planetary nebula, designated Shapley 1 after the famous astronomer Harlow Shapley, has a very apparent annular ring like structure. Although some of these nebula appear like planets on the sky (hence their name), they actually surround stars far outside our Solar System.
Betelgeuse, Betelgeuse, Betelgeuse

Credit: (1997-02-16)
Betelgeuse (sounds a lot like "beetle juice"), a red supergiant star about 600 light years distant, is seen in this Hubble Space Telescope image -- the first direct picture of the surface of a star other than the Sun. A bright, as yet unexplained hotspot is revealed on its surface!  While Betelgeuse is cooler than the Sun, it is more massive and over 1000 times larger. If placed at the center of our Solar System, it would extend past the orbit of Jupiter. Betelgeuse is also known as Alpha Orionis, one of the brightest stars in the familar constellation of Orion, the Hunter. Like many star names, Betelgeuse is Arabic in origin. It is derived from a phrase which refers to the hunter's shoulder or armpit, the general area occupied by this star in drawings of the figure in the constellation. As a massive red supergiant, it is nearing the end of its life and will soon become a supernova.
A Wind From The Sun

Credit: (1997-02-17)
A wind from the Sun blows through our Solar System. The behaviour of comet tails as they flapped and waved in this interplanetary breeze gave astronomers the first hint of its existence. Streaming outward at 250-400 miles/second, electrons and ions boiling off the Sun's incredibly hot but tenuous corona account for the Solar Wind - now known to affect the Earth and other planets along with voyaging spacecraft. Rooted in the Solar Magnetic Field, the structure of the corona is visible in this composite image from the EIT and UVCS instruments onboard the SOHO spacecraft, extending a million miles above the Sun's surface. The dark areas, known as coronal holes, represent the regions where the highest speed Solar Wind originates.
A Big Cliff on Jupiter's Callisto
Credit: (1997-02-18)
Callisto's surface is not without fault. In fact, an explorer crossing the surface of this large moon of Jupiter would need climbing equipment to pass this large, recently discovered fault. The above picture was released last week and was taken in November 1996 by the robot spacecraft Galileo currently orbiting Jupiter. As the Sun illuminates Callisto's surface from the left, the unusual cliff or scarp stands out by the shadow it casts to the right. This cliff and others were probably formed when a large object collided with Callisto early in its history. Of the many visible craters in the above photograph, the smallest visible is about a football field across, while the largest is more than a kilometer.
Mizar Binary Star

Credit: (1997-02-19)
Mizar (sounds like "My Czar") is a binary star. In fact, most stars are binary stars. In a binary star system, each star of the pair follows an elliptical orbital path. Mutual gravity causes the stellar companions to glide around their orbits as if tied to the ends of an elastic string passing through a balance point between them. The balance point is the system's "center of mass". Also known as zeta Ursae Majoris, Mizar is the middle star in the handle of the Big Dipper and at a distance of 88 light years, was the first binary star system to be imaged telescopically. Spectroscopic observations of the Mizar system show periodic doppler shifts, revealing that both stars, Mizar A and Mizar B, are themselves binary stars! But, the companions are too close to be directly observed as separate stars, even by the largest telescopes. In developing a new optical interferometer capable of extremely high resolution while peering through the Earth's blurry atmosphere, U.S. Naval Observatory and Naval Research Lab astronomers have been able to detect the companion star to Mizar A. This composite image of their observations shows the daily and monthly relative orbital motion in the binary system. Binary stars are a boon to astronomers because these stars can be weighed -- their orbits providing a direct measurement of star masses.
Comet Hale-Bopp and the Dumbbell Nebula
Credit and Copyright: (1997-02-20)
Comet Hale-Bopp is now slowly moving across the morning sky. During its trip to our inner Solar System, the comet passes in front of several notable objects. Here Comet Hale-Bopp was photographed on February 11th superposed nearly in front of the picturesque Dumbbell Nebula, visible on the upper right. Comet Hale-Bopp is now first magnitude - one of the brightest objects in the morning sky. APOD, always in search of interesting and accurate astronomy pictures, issues the following informal challenge: that Comet Hale-Bopp be photographed in color with both easily recognizable foreground and background objects. For instance, in late March, it might be possible to photograph the comet with the Eiffel Tower in the foreground and the Andromeda galaxy (M31) in the background. Such superpositions would not only contrast human and cosmic elements, but give angular perspective on the size of the comet's tail.
New Eyes for the Hubble Space Telescope
Credit: (1997-02-21)
The Hubble Space Telescope's second servicing mission has been completed. Every few years, the telescope is visited by a Space Shuttle to allow astronauts to switch old instruments for new. This time, the Goddard High Resolution Spectrograph and Faint Object Spectrograph were replaced by the Near Infrared Camera and Multi-Object Spectrometer and the Space Telescope Imaging Spectrograph. These new instruments will act like eyes sharing the 2.4-meter telescope mirror with the remaining instruments: the Wide Field Planetary Camera 2 and the Faint Object Camera. The Hubble Space Telescope can take clearer pictures than ground based telescopes because its images are not blurred by the Earth's atmosphere. Pictured in the final phases of a space walk from the second servicing mission, astronauts Mark Lee (right) and Steven Smith work on HST while perched on the Shuttle's remote manipulator arm.
The Gamma Ray Sky
Credit: (1997-02-22)
What if you could "see" gamma rays? If you could, the sky would seem to be filled with a shimmering high-energy glow from the most exotic and mysterious objects in the Universe. In the early 1990s NASA's orbiting Compton Observatory, produced this premier vista of the entire sky in gamma rays - photons with more than 40 million times the energy of visible light. The diffuse gamma-ray glow from the plane of our Milky Way Galaxy runs horizontally through the false color image. The brightest spots in the galactic plane (left of center) are pulsars - spinning magnetized neutron stars formed in the violent crucibles of stellar explosions. Above and below the plane, quasars, believed to be powered by supermassive black holes, produce gamma-ray beacons at the edges of the universe. The nature of many of the fainter sources remains unknown.
Cartwheel of Fortune
Credit: (1997-02-23)
By chance, a collision of two galaxies has created a surprisingly recognizable shape on a cosmic scale - "The Cartwheel Galaxy". The Cartwheel is part of a group of galaxies about 500 million light years away in the constellation of Sculptor (two smaller galaxies in the group are visible on the right). Its rim is an immense ring like structure 100,000 light years in diameter composed of newly formed, extremely bright, massive stars. When galaxies collide they pass through each other, their individual stars rarely coming into contact. However, the galaxies' gravitational fields are seriously distorted by the collision. In fact, the ring-like shape is the result of the gravitational disruption caused by a small intruder galaxy passing through a large one, causing a a star formation wave to move out from the impact point like a ripple across the surface of a pond. In this case the large galaxy may have originally been a spiral, not unlike our own Milky Way, transformed into the wheel shape by the collision. But ... what happened to the small intruder galaxy?
The Trail of the Intruder
Credit: (1997-02-24)
In yesterday's episode our hero, the Cartwheel galaxy, had survived a chance cosmic collision with a small intruder galaxy - triggering an expanding ring of star formation. Hot on the intruder's trail, a team of multiwavelength sleuths have compiled evidence tracking the reckless galaxy fleeing the scene. Presented for your consideration: a composite showing a visual image of the Cartwheel galaxy (at left) and smaller galaxies of the Cartwheel group, superposed with high resolution radio observations of neutral hydrogen (traced by the green contours). The neutral hydrogen trail suggestively leads to the culprit galaxy at the far right, presently about 250,000 light years distant from the Cartwheel!
Star Wars in NGC 664
Credit: (1997-02-25)
Long ago in a galaxy far, far away, locked in their final desperate struggle against the force of gravity ... two stars exploded! Stellar explosions - Supernovae - are among the most powerful events in the Universe, estimated to release an equivalent energy of up to 1 million trillion trillion (1 followed by 30 zeros) megatons of TNT. After the explosion, an expanding supernova envelope is observed to brighten over a a period of days to a maximum light output which rivals that of an entire galaxy before fading from view over the following months. Triggered by the collapsing core of a massive star or the nuclear demise of a white dwarf supernovae occur in average spiral galaxies only about once every 25-100 years. But a recent observation of NGC 664, a spiral galaxy about 300 million light years distant, captured a rare and colorful performance - two supernovae from the same galaxy. In this monitoring exposure the two supernovae, one reddish yellow and one blue, form a close pair just below the image center (to the right of the galaxy nucleus). The color difference is due to temperature - blue is hotter.
Sungrazer
Credit: (1997-02-26)
Arcing toward a fiery fate, this Sungrazer comet was recorded by the SOHO spacecraft's Large Angle Spectrometric COronagraph (LASCO) on Dec. 23rd, 1996. LASCO uses an occulting disk, partially visible at the lower right, to block out the otherwise overwhelming solar disk allowing it to image the inner 5 million miles of the relatively faint corona. The comet is seen as its coma enters the bright equatorial solar wind region (oriented vertically). Spots and blemishes on the image are background stars and camera streaks caused by charged particles. Positioned in space to continuously observe the Sun, SOHO has detected 7 sungrazing comets. Based on their orbits, they are believed to belong to a family of comets created by successive break ups from a single large parent comet which passed very near the sun in the twelfth century. The bright comet of 1965, Ikeya-Seki, was also a member of the Sungrazer family, coming within about 400,000 miles of the Sun's surface. Passing so close to the Sun, Sungrazers are subjected to destructive tidal forces along with intense solar heat. This comet, known as SOHO 6, did not survive.
Comet Hale-Bopp is That Bright
Credit and Copyright: (1997-02-27)
What's that fuzzy star? It's not a star, it's Comet Hale-Bopp. Not only has Comet Hale-Bopp become easy to see in the morning sky, it has become hard not to see it. It's that bright. Any morning just before sunrise, look towards the east. Comet Hale-Bopp is one of the brightest objects up. Its dominating presence is shown dramatically by this photo taken just west of Williston, North Carolina, USA. Here Comet Hale-Bopp shines above the telephone poles lining Highway 70. Too tired to get up in the morning to see the comet? Don't worry, in less than a month it will also be visible in the evening sky, just before sunset. And it will have a longer tail. From the Space Shuttle, Dr. Steven Hawley says, "Hale-Bopp looks great."
Edge-On Spiral Galaxy NGC 891
Credit and Copyright: (1997-02-28)
Is our Galaxy this thin? We believe so.  The Milky Way, like NGC 891 pictured above, has the width of a typical spiral galaxy. Spirals have most of their bright stars, gas, and obscuring dust in a thin disk. This disk can be so thin the spiral galaxy appears edge-on like a compact disk seen sideways. The dark band across the middle is a lane of dust which absorbs light. Some of the billions of stars that orbit the center of NGC 891, however, appear to be moving too fast to just be traveling in circles. What causes this peculiar motion? One hypothesis is that NGC 891 has a large bar across its center - a bar that would be obvious were we to see this galaxy face-on instead of edge-on. This false color picture was constructed from 3 near infrared images.
Galaxy  Dwingeloo 1 Emerges 
Credit: (1997-03-01)
Sometimes you can't see the forest for the trees. But if you look closely at the center of the above photograph, you will see a whole spiral galaxy behind the field of stars. Named Dwingeloo 1, this nearby galaxy was only discovered recently (1994) because much of its light was obscured by dust, gas and bright stars of our own Milky Way Galaxy. In fact, all the individually discernible stars in the above photograph are in our Galaxy. Dwingeloo 1 turned out to be a large galaxy located only five times as distant as the closest major galaxy - M31.
Hawaii
Credit: (1997-03-02)
Aloha! With the graceful arc of the Earth's limb in the background, the entire Hawaiian Island archipelago is visible in this stunning photo taken by the astronauts onboard the shuttle Discovery in October of 1988. Along with popular beaches and tropical resorts, these volcanic islands offer extreme elevations with dark, dry, cloudless skies. Consequently they have also become popular sites for sophisticated ground based telescopes. The peak of Mauna Kea, on the Big Island (upper left), boasts an impressive array of astronomical instruments including the Keck, the Canada-France-Hawaii Telescope, the NASA IRTF, the JCMT and UKIRT, and the Gemini Telescope Project. The dormant volcanic cone of Haleakala on Maui (just below the Big Island) is home to the Air Force Maui Optical Station and the Mees Solar Observatory. Mahalo nui loa!
Pioneer 10: The First 6 Billion Miles
Illustration Credit: (1997-03-03)
Q: What was made by humans and is 6 billion miles away? A: Pioneer 10 - and yesterday was the 25th anniversary of its launch. More than 9 light hours distant, Pioneer 10 is presently about twice as far from the Sun as Pluto, bound for interstellar space at 28,000 miles per hour. The distinction of being the first human artifact to venture beyond the Solar System is just one in a long list of firsts for this spacefaring ambassador, including; the first spacecraft to travel through the asteroid belt and explore the outer Solar System, the first spacecraft to visit Jupiter, the first to use a planet's gravity to change its course and to reach solar-system-escape velocity, and the first spacecraft to pass beyond the known planets. Pioneer 10's mission is nearing an end - now exploring the distant reaches of the heliosphere it will soon run out of sufficient electrical power to operate science instruments. However, the 570 lb. spacecraft will continue to coast and in 30,000 years or so it will pass within about 3 light years of a nearby star. The star itself, a faint red dwarf known as Ross 248, is just over 10 light years distant in the constellation of Taurus.
Solar Wind And Milky Way
Credit: (1997-03-04)
The Sun is bright, so bright that it overwhelms the light from other stars even for most satellite-borne telescopes. But LASCO, a coronograph onboard the space-based SOHO Observatory, uses occulting disks to block the intense solar light and examine the tenuous, hot gases millions of miles above the Sun's surface. In this LASCO image from December 24, 1996, an occulting disk (center) and mechanical support (extending from the lower left) are visible along with the billowing Solar Wind. Appearing in the background are faint stars and obscuring dust clouds toward the center of our Milky Way Galaxy! The field of view covers about 16 degrees, corresponding to 28 million miles at the distance of the Sun - just under half the diameter of Mercury's orbit. A prominent dark interstellar dust cloud cuts through the Milky Way starfield running approximately south (lower right) to north. Blemishes on the image are camera streaks caused by charged particles.
In the Center of NGC 604 
Credit: (1997-03-05)
Stars are sometimes born in the midst of chaos. About 3 million years ago in the nearby galaxy M33, a large cloud of gas spawned dense internal knots which gravitationally collapsed to form stars. But NGC 604 was so large, it could form enough stars to make a globular cluster. Many young stars from this cloud are visible above, along with what is left of the initial gas cloud. Some stars were so massive they have already evolved and exploded in a supernova.  The brightest stars that are left emit light so energetic that they create one of the largest cloud of ionized hydrogen gas known, second only to the 30 Doradus Cluster in Milky Way's close neighbor, the Large Magellanic Cloud.
Hubble Floats Free 
Credit: (1997-03-06)
Why put observatories in space? Most telescopes are on the ground. On the ground, you can deploy a heavier telescope and upgrade it more easily. The trouble is that Earth-bound telescopes must look through the Earth's atmosphere. First, the Earth's atmosphere blocks out a broad range of the electromagnetic spectrum, allowing a narrow band of visible light to reach the surface. Telescopes which explore the Universe using light beyond the visible spectrum, such as those onboard the Compton Observatory (gamma rays), the ASCA satellite (x-rays), or the new ultraviolet and infrared instruments on the above-pictured Hubble Space Telescope (HST), need to be carried above the absorbing atmosphere. Second, the Earth's atmosphere blurs the light it lets through. The blurring is caused by varying density and continual motion of air. By orbiting above the Earth's atmosphere, the Hubble can get clearer images. In fact, even though HST has a mirror 15 times smaller than large Earth-bound telescopes, it can still resolve detail almost 100 times finer.