omnianasa/nasa-apod-metadata huggingface dataset:
Mercury Astronauts and a Redstone
Credit: (1997-04-06)
Space suited project Mercury astronauts John H. Glenn, Virgil I. Grissom, and Alan B. Shepard Jr. (left to right) are pictured here posing in front of a Redstone rocket in this vintage 1961 NASA publicity photo. Project Mercury was the first U.S. program designed to put humans in space. It resulted in 6 flights using one-man capsules and Redstone and Atlas rockets. Shortly after the first U.S. manned flight on May 5, 1961, a suborbital flight piloted by Alan Shepard, President Kennedy announced the goal of a manned lunar landing by 1970. This goal was achieved by NASA's Apollo program and Shepard himself walked on the moon as commander of the Apollo 14 mission.
GRB970228: What's There? 
Credit: (1997-04-07)
Could this fuzzy blob be the key to the whole gamma-ray burst (GRB) mystery? Astronomers the world over are now scrambling to determine the true nature of the extended emission seen to the lower right of the bright source in the above image. The bright object in the center is rapidly fading - and thought to be the first true optical counterpart to a GRB. But is it housed in a galaxy? If so, after the central emission has faded, this galaxy should be identifiable. Today, follow up observations of this blob are planned with the Hubble Space Telescope. If the extended emission does come from a galaxy it would bolster indications that the February 28th GRB occurred in that galaxy, across the universe from us.  This, in turn, would imply that GRBs are truly the most powerful explosions ever known.
Comet Hale-Bopp Over New York City 
Credit and Copyright: (1997-04-08)
What's that point of light above the World Trade Center? It's Comet Hale-Bopp! Both faster than a speeding bullet and able to "leap" tall buildings in its single orbit, Comet Hale-Bopp is also bright enough to be seen even over the glowing lights of one of the world's premier cities. In the foreground lies the East River, while much of New York City's Lower Manhattan can be seen between the river and the comet.  Comet Hale-Bopp is now moving away from both the Sun and the Earth. It should, however, should remain visible even in northern cities for at least a month. To find Comet Hale-Bopp, look for the brightest object in the northwest sky just after sunset - or wait for its return in 2400 years.
Oceans Under Jupiter's Europa? 
Credit: (1997-04-09)
Is there life beneath Europa? Today, new results are being announced (at about 2 pm EST) about the possibility of oceans under Jupiter's moon Europa. The existence of such oceans increases the likelihood that some sort of life exists beneath the fractured ice planes of Jupiter's smoothest satellite. Results from the February 20th flyby of the robot spacecraft Galileo past Europa now clearly indicate that either large bodies of water or slush exist under a relatively thin ice sheet covering the moon's surface, at least in some regions. Areas on the surface are marked by very few craters, indicating that water flowed there in the time since most craters formed.
Europa's Ice Rafts 
Credit: (1997-04-10)
The surface of Jupiter's moon Europa has shifted. Photographs released yesterday of Europa's surface taken by the spacecraft Galileo show that the smooth moon's icy surface is sometimes like a giant scrambled jigsaw puzzle. Pieces of Europa's surface, identifiable above, have rafted to new locations. Also visible are larger areas that are clearly shifted from their original alignment. What could cause this surface shuffle? One leading explanation is water - oceans of water just beneath Europa's ice plains. This discovery again fuels speculation that life might exist far from the comfort of Earth.
The Sun Puffs 
Credit: (1997-04-11)
The Earth has once again endured a burst of particles from the Sun. The latest storm, which began Monday, was one of the best documented solar storms to date. At 10 am (EDT) ground monitors of the SOHO spacecraft, which continually monitors the Sun, noticed a weak spot in the solar corona was buckling again, this time letting loose a large, explosive Coronal Mass Ejection (CME). Almost simultaneously, NASA's WIND spacecraft began detecting bursts of radio waves from electrons involved in this magnetic storm. Supersonic waves rippled though the solar corona as a puff of high energy gas shot out into the Solar System. The above image shows two photographs of the Sun taken about 15 minutes apart and subtracted, highlighting the explosion. The CME gas will have little lasting effect on the Earth, but might make this a good weekend to see an aurora.
Arecibo: The Largest Telescope 
Credit: (1997-04-12)
The Arecibo radio telescope is currently the largest single-dish telescope in the world. First opening in 1963, this 305 meter (1000 foot) radio telescope resides in a natural valley of Puerto Rico. The Arecibo telescope has been used for many astronomical research projects, including searches and studies of pulsars, and mapping atomic and molecular gas in the Galaxy and the universe. As the Arecibo dish can also be used to send radio waves, it has bounced and recorded radiation off of planets in our Solar System, and has even broadcast messages to areas of the Galaxy that might contain intelligent extra-terrestrial life. Any person in the world may use the telescope, providing their proposal is selected by a review committee.
Jets From SS433 
Credit: (1997-04-13)
SS433 is one of the most exotic star systems known. Its unremarkable name stems from its inclusion in a catalog of stars which emit radiation characteristic of atomic hydrogen. Its very remarkable behavior stems from a compact object, a black hole or neutron star, which has produced an accretion disk with jets. As illustrated in this artist's vision of the SS433 system based on observational data, a massive, hot star (left) is locked in a mutual orbit with a compact object. Material transfers from the massive star into an accretion disk surrounding the compact object blasting out two jets of ionized gas in opposite directions - at about 1/4 the speed of light! Radiation from the jet tilted toward the observer is blueshifted, while radiation from the jet tilted away is redshifted. The binary system itself completes an orbit in about 13 days while the jets precess (wobble like a top) with a period of about 164 days. Are the jets from SS433 related to those from black holes at the centers of galaxies?
Hale-Bopp's Hoods 
Credit: (1997-04-14)
Comet Hale-Bopp is spinning. The nucleus of the comet is a dirty snowball about 25 miles in diameter that spins about once every 12 hours. As Comet Hale-Bopp spins, parts of the comet's surface shoot away in jets. Ejected material therefore makes rings, which appear in above photograph as "hoods" in the coma. Even though the central part of Comet Hale-Bopp's coma is quite condensed, the nucleus is not visible. Comet Hale-Bopp is now headed south, away from the Sun, and is getting dimmer. At its brightest last week, it was even brighter than Comet Hyakutake was last year, although with a less prominent tail. Comet Hale-Bopp will still be easily visible to northern observers for several weeks in the northwest sky after sunset.
Hale-Bopp and Plateau de Bure Interferometer 
Credit and Copyright: (1997-04-15)
Comet Hale-Bopp is being observed by many different telescopes. Here the comet is pictured behind the array of radio telescopes which compose the Plateau de Bure Interferometer. These telescopes are being used to detect the presence of different molecules in the coma and tail of Comet Hale-Bopp. Molecules detected in the comet include carbon monoxide and sulfur dioxide. The abundance of different types of molecules in Comet Hale-Bopp's coma give clues to its composition and history, as well as clues to the composition and history of our Solar System. Comet Hale-Bopp has now rounded the Sun and is headed back out. It can still be seen by northern observers for several weeks in the northwest sky after sunset.
A Star Cluster Through Hale-Bopp's Tail 
Credit and Copyright: (1997-04-16)
Comet Hale-Bopp continues to look impressive. The photograph above captured the comet on April 7th passing nearly in front of M34, a star cluster in the constellation of Perseus. Many of the stars in this open cluster can be seen through Comet Hale-Bopp's white dust tail. The bright blue ion tail now shows several streams. Now receding from both the Sun and the Earth, Comet Hale-Bopp should still remain an impressive sight for weeks to come as it slowly fades.
Pwyll: Icy Crater of Europa 
Credit: (1997-04-17)
The impact crater Pwyll (a name from Celtic Mythology) is thought to represent one of the youngest features on the surface of Jupiter's moon Europa. A combination of color and high resolution black and white data from NASA's Galileo spacecraft was used to produce this view looking down on the crater with the sun illuminating the scene from the right. Pwyll's visible dark central region is about 24 miles in diameter, while brilliant white rays of debris blasted from the impact site extend outward for hundreds of miles. The white debris or ejecta clearly overlays everything else on the surface - indicating that this formation is younger than all surrounding features. Interestingly, the bright white color suggests a composition of fresh water ice particles. Does water in liquid form exist below Europa's icy surface?
Solar Storm Causes X-Ray Aurora
Credit: (1997-04-18)
On April 7, the SOHO spacecraft spotted a Solar Storm ejecting a cloud of energetic particles toward planet Earth. The plasma cloud's center missed Earth, but high energy particles swept up by Earth's magnetosphere still created a geomagnetic storm! Residents of northerly lattitudes were treated to the spectacle of brilliant aurora as curtains of green and white light danced across the sky. In this image from April 11, the Polar Ionospheric X-ray Imaging Experiment (PIXIE) onboard NASA's orbiting POLAR spacecraft records the strongest X-ray aurora seen in more than a year of operation. The false color image overlaying a map of North America reveals X-rays generated in the upper atmosphere by showers of high energy electrons.
Spiral Galaxy M83 
Credit and Copyright: (1997-04-19)
The long winding arms of this nearby spiral galaxy define it as the "Southern Pinwheel." But M83 is quite a typical spiral - much like our own Milky Way Galaxy. Spiral galaxies contains many billions of stars, the youngest of which inhabit the spiral arms and glow strongly in blue light. Dark dust lanes are mixed in with the stars and help define M83's marked spiral structure. The space between the spiral arms is also filled with stars - but stars that are typically more dim and red.  M83 has shown an unusual amount of stellar supernovae explosions - six since the turn of the century - more than any other Messier galaxy.
Moon Robot: Lunokhod 1
Credit: (1997-04-20)
On November 17, 1970 the Soviet Luna 17 spacecraft landed the first roving remote-controlled robot on the Moon. Known as Lunokhod 1, it weighed just under 2,000 pounds and was designed to operate for 90 days guided by a 5-person team at the Deep Space Center near Moscow, USSR, Planet Earth. Lunokhod 1 actually toured the lunar Mare Imbrium (Sea of Rains) for 11 months in one of the greatest successes of the Soviet lunar exploration program. The futuristic looking eight wheeler is pictured here in an artist's conception atop its landing module. Ramps extend from both sides of the spacecraft allowing an alternative route to the surface if one side is blocked by boulders.
Big Sky Comet 
Credit and Copyright: (1997-04-21)
On April 17th, "Big Sky" country sure lived up to its name. The dark skies over the US states of Wyoming, Montana and the Dakotas were quite busy, as shown by this photograph featuring Comet Hale-Bopp. In the foreground is the Absaroka Mountain Range in Wyoming, lit by reflected moonlight. Just to the left of Jim Mountain's peak is Comet Hale-Bopp. The unusual colors visible on the far right are aurora, remnants of the recent solar storm recorded on the Sun.  Across the middle of the photo are numerous bright stars, and across the top of the picture are clouds.
Historic Optical Flash Fades 
Credit and Copyright: (1997-04-22)
The largest telescopes in the world have scrambled to point toward this faint, fading object. Why? Because it may well be the first active optical counterpart ever found for a gamma-ray burst, and could hold the clue to the distance scale to this most enigmatic class of astronomical objects.  During the past two months, multiwavelength observations, claims, and counterclaims have been exchanged at a torrential pace, as astronomers wait impatiently to see what setting houses the fading transient. Above are two pictures of the optical transient (OT), one taken on February 28th, the other about a week later on March 8th. The OT arrows show the source that faded from view during this time. The OT has been examined by large telescopes including the Hubble Space Telescope and Keck, yet researchers are still scrambling to get answers to fundamental questions about its true nature. Does the OT actually move (exhibit proper motion)? Is there a faint galaxy superposed behind the OT or is this extended emission fading too? In the face of intense scrutiny with the world's most capable telescopes, the origin of gamma-ray bursts so far remains mysterious!
Antlia: A New Galactic Neighbor 
Credit and Copyright: (1997-04-23)
Meet Antlia, a newly discovered neighbor of our Milky Way Galaxy. Announced just last week, this faint member of our Local Group of Galaxies has only about one million stars. It is late in being noticed because it is so hard to see against a bright sky. This faint galaxy is seen here in the background - the bright stars visible are in our own galaxy. The Antlia Dwarf Galaxy is actually a dwarf spheroidal galaxy, similar to nine known dwarf spheroidals that orbit our Milky Way Galaxy. Antlia, named for the constellation in which it resides, is unusual because it does not hover near either of the two major galaxies of the Local Group: our Milky Way Galaxy and M31.
The Frothy Milky Way 
Credit: (1997-04-24)
Astronomers have recently discovered that looking at dust along the plane of our Milky Way Galaxy is a bit like looking into a frothy glass of beer. The dust between stars in our galaxy is arranged like a foam with bubbles and voids -- apparently churned by shocks and winds generated as stars cycle through their lives. This processed infrared image, based on data from NASA's IRAS satellite, maps the radiation from the edges of galactic dust clouds and reveals the complex distribution. The image covers an area of about 40x60 degrees centered on the galactic plane near the Cygnus region. It shows bright bubble-shaped and arc-like dust clouds around the supernova remnants and starbirth regions embedded in the galactic disk.
Hale-Bopp Polarized 
Credit and Copyright: (1997-04-25)
Light polarization is familiar to many outdoor enthusiasts who use polarizing sunglasses to cut the glare of reflected light. These two views of comet Hale-Bopp also demonstrate the effect of polarization. At left is an "ordinary intensity image" of Hale-Bopp's coma taken April 14, while on the right a similar image made with polarizing filters represents the intensity of polarized light. The arcs visible in the polarized view probably correspond to concentrations of ejected cometary dust that produce polarization by reflecting sunlight. Any sort of reflection - from clumps of comet dust or the surface of your favorite lake or ski slope - can polarize light by causing the light waves to vibrate in a plane defined by the reflecting surface.
The Perseus Cluster of Galaxies 
Credit: (1997-04-26)
Here is one of the largest objects that anyone will ever see on the sky. Each of the fuzzy blobs in the above picture is a galaxy, together making up the Perseus Cluster, one of the closest clusters of galaxies. We view the cluster through the foreground of faint stars in our own Milky Way Galaxy. It takes light roughly 300 million years to get here from there, so we only see this cluster as it existed during the age of the dinosaurs. Also known as Abell 426, the center of Perseus cluster is a prodigious source of X-ray radiation, and so helps astronomers study how clusters formed and how gas and dark matter interact. The Perseus Cluster of Galaxies is part of the Pisces-Perseus supercluster of galaxies, which spans over 15 degrees and contains over 1000 galaxies.
Sputnik: Traveling Companion 

Courtesy: (1997-04-27)
Sputnik means "traveling companion". Despite the innocuous sounding name, the launch of the Earth's first "artificial moon", Sputnik 1, by the Soviets on October 4, 1957 shocked the free world, setting 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 Soviets followed this success by launching a dog into orbit aboard Sputnik 2.
Io's Sodium Cloud
Credit: (1997-04-28)
Io has its own cloud.  Jupiter's most active moon is visible on the left of the above false-color photograph, with its left side illuminated by sunlight.  But what is happening on Io's right side?  Here a plume of gas from the active volcano Prometheus also reflects sunlight.  A second active volcano, Pele, is also visible: marked by the red spot just below Io's center. Surrounding the moon is a yellow haze originating from gas ejected by Io's volcanos.  Sodium atoms in the gas cloud are particulary efficient at reflecting yellow light.  Several points of light are background stars.
Hale Bopp and Orion
Credit and Copyright: (1997-04-29)
Comet Hale-Bopp is still brighter than most constellations.  In fact, Comet Hale-Bopp may now hold the record for staying bright the longest. Last week the comet was photographed above in the same field as the constellation Orion, visible in the photograph's center, as well as with Sirius, the brightest star in the night, visible on the far left. Just below Comet Hale-Bopp on the right is the volcanic caldera known as White Mountain.. As the comet heads south, it has become visible to most of the world, now including many observers in the Earth's Southern Hemisphere.
Milky Way Molecule Map
Credit: (1997-04-30)
Where are the Milky Way's gas clouds and where are they going?  Stars form in gas clouds, and the motion of gas clouds tell us about the size and rotation speed of our own Milky Way Galaxy. But gas clouds are hard to detect - they are composed mostly of nearly invisible molecular hydrogen and helium. Fortunately, at least small amounts of heavier gases co-exist, one of them being carbon monoxide (CO), which is relatively easy to detect at radio wavelengths. Therefore, over the past decade, a team of astronomers have carefully mapped out the molecular sky to unprecedented clarity - to about four times previous resolution and about eight times previous sensitivity. The resulting map is shown above, rescaled and in false color, with dark blue being relatively low emission.  The band of our Milky Way Galaxy spans the middle. The data have not only helped our understanding of the Galaxy, but highlight a few mysteries too. For example: what causes the rapid speed of the gas near the Galactic Center?
A Galactic Cloud of Antimatter
Credit: (1997-05-01)
The center of our Milky Way Galaxy is full of surprises. Its latest spectacular is a mysterious cloud glowing in gamma rays produced by annihilating antimatter particles! Star Trek fans are all too familiar with the consequences of mixing matter (electrons) and antimatter (positrons) - the particles catastrophically annihilate converting their masses to energy according to Einstein's famous E=mc2. Positron/electron annihilation energy is emitted as gamma rays with photon energies of 511,000 electron volts. Searching for these high energy photons, the OSSE instrument onboard NASA's orbiting Compton Gamma Ray Observatory has recently produced this map of the Galactic Center (GC) region. As anticipated, it shows annihilation gamma rays as a bright spot at the GC with fainter horizontal emission from the galactic plane. Astoundingly, it also reveals a large and unexpected cloud of annihilation radiation, probably about 4,000 light years across, extending nearly 3,500 light years above the GC. What could have created this cloud? Associated with no previously known object, it seems to imply that a fountain of antimatter positrons streams from the GC. Present guesses about the source of the positrons include the violent and exotic environments surrounding starbirth, neutron star collisions, and black holes at the GC. Are there other such clouds in our Galaxy?
X-Rays From IC 443
Credit: (1997-05-02)
The life-cycles of stars help drive the ecology of our Galaxy, churning, processing, and redistributing matter. Massive stars reach a spectacular evolutionary endpoint - supernovae explosions which blast off their outer layers, violently merging stellar material with the gas and dust of the Milky Way. The supernova remnant IC 443 is typical of the aftermath. Seen in this false color X-ray image are the shocked, expanding shells of gas from a star which exploded thousands of years ago. Known to be interacting with galactic molecular clouds, the expanding supernova remnant was also recently discovered to have regions of intense higher energy X-ray emission (coded blue in this map) near the molecular cloud boundaries. This X-ray emission may indicate that electrons are being accelerated within the remnant, gaining in energy as they surf back and forth across the expanding shock wave. If so, IC 443 could also be one source of our Galaxy's puzzling high energy cosmic-rays.
Giant Cluster Bends, Breaks Galaxy Images
Credit: (1997-05-03)
What are those strange blue objects? Many are images of a single, unusual, beaded, blue, ring-like galaxy which just happens to line-up behind a giant cluster of galaxies. Cluster galaxies here appear yellow and -- together with the cluster's dark matter -- act as a gravitational lens. A gravitational lens can create several images of background galaxies, analogous to the many points of light one would see while looking through a wine glass at a distant street light. The distinctive shape of this background galaxy -- which is probably just forming -- has allowed astronomers to deduce that it has separate images at 4, 8, 9 and 10 o'clock, from the center of the cluster. Possibly even the blue smudge just left of center is yet another image! This spectacular photo from HST was taken in October 1994. The first cluster lens was found unexpectedly by Roger Lynds (NOAO) and Vahe Petrosian (Stanford) in 1986 while testing a new type of imaging device.  Lensed arcs around this cluster, CL0024+1654, were first discovered from the ground by David Koo (UCO Lick) in 1988.
The Last Moon Shot

Credit: (1997-05-04)
In 1865 Jules Verne predicted the invention of a space capsule that could carry people. In his science fiction story "From the Earth to the Moon", he outlined his vision of a cannon in Florida so powerful that it could shoot a "Projectile-Vehicle" carrying three adventurers to the Moon. Over 100 years later, NASA, guided by  Wernher Von Braun's vision, produced the  Saturn V rocket. From a spaceport in Florida, this rocket turned Verne's fiction into fact, launching 9 Apollo Lunar missions and allowing 12 astronauts to walk on the Moon. Pictured is the last moon shot, Apollo 17, awaiting a night launch in December of 1972. Spotlights play on the rocket and launch pad while the full Moon looms in the background.  Humans have not walked on the lunar surface since. Should we return to the Moon?