omnianasa/nasa-apod-metadata huggingface dataset:
The Galaxy Above (2019-10-15)
Have you contemplated your home galaxy lately?  If your sky looked like this, perhaps you'd contemplate it more often! The featured picture is actually a composite of two images taken last month from the same location in south Brazil and with the same camera -- but a few hours apart.  The person in the image -- also the astrophotographer -- has much to see in the Milky Way Galaxy above. The central band of our home Galaxy stretches diagonally up from the lower left. This band is dotted with spectacular sights including dark nebular filaments, bright blue stars, and red nebulas.  Millions of fainter and redder stars fill in the deep Galactic background.  To the lower right of the Milky Way are the colorful gas and dust clouds of Rho Ophiuchi, featuring the bright orange star Antares.  On this night, just above and to the right of Antares was the bright planet Jupiter.  The sky is so old and so familiar that humanity has formulated many stories about it, some of which inspired this very picture.
BHB2007: A Baby Binary Star in Formation (2019-10-16)
How do binary stars form? To help find out, the Atacama Large Millimeter Array (ALMA) recently captured one of the highest resolution images yet taken of a binary star system in formation.  Most stars are not alone -- they typically form as part of a multiple star systems where star each orbits a common center of gravity.  The two bright spots in the featured image are small disks that surround the forming proto-stars in [BHB2007] 11, while the surrounding pretzel-shaped filaments are gas and dust that have been gravitationally pulled from a larger disk.  The circumstellar filaments span roughly the radius of the orbit of Neptune.  The BHB2007 system is a small part of the Pipe Nebula (also known as Barnard 59), a photogenic network of dust and gas that protrudes from Milky Way's spiral disk in the constellation of Ophiuchus. The binary star formation process should be complete within a few million years.
Moons of Saturn (2019-10-17)
On July 29, 2011 the Cassini spacecraft's narrow-angle camera took this snapshot and captured 5 of Saturn's moons, from just above the ringplane. Left to right are small moons Janus and Pandora respectively 179 and 81 kilometers across, shiny 504 kilometer diameter Enceladus, and Mimas, 396 kilometers across, seen just next to Rhea. Cut off by the right edge of the frame, Rhea is Saturn's second largest moon at 1,528 kilometers across. So how many moons does Saturn have? Twenty new found outer satellites bring its total to 82 known moons, and since Jupiter's moon total stands at 79, Saturn is the Solar System's new moon king. The newly announced Saturnian satellites are all very small, 5 kilometers or so in diameter, and most are in retrograde orbits inclined to Saturn's ringplane. You can help name Saturn's new moons, but you should understand the rules. Hint: A knowledge of Norse, Inuit, and Gallic mythology will help.
Interstellar Interloper 2I/Borisov (2019-10-18)
After the 2017 detecton of 1I/'Oumuamua, comet 2I/Borisov has become the second recognized interstellar interloper. Like 'Oumuamua, Borisov's measured hyperbolic trajectory and speed as it falls toward the Sun confirm that its origin is from beyond our Solar System. But while detailed observations indicate 'Oumuamua is a rocky body with differences from known Solar System objects, Borisov is definitely a far wandering comet. Taken on October 12, 2019 this Hubble Space Telescope image of Borisov reveals a familiar looking comet-like activity and concentration of dust around around its nucleus. Not resolved in the image, some estimates suggest the nucleus could be between 2 and 16 kilometers in diameter. At the time of the Hubble image, comet 2I/Borisov was about 418 million kilometers away. Borisov is still inbound though and will make its closest approach to the Sun on December 7 at a distance of about 300 million kilometers (2 Astronomical units).
All Female Spacewalk Repairs Space Station (2019-10-19)
The failed unit was beyond the reach of the robotic Canadarm2.  Therefore, this repair of the International Space Station would require humans. The humans on duty were NASA's Jessica Meir and Christina Koch. This was the fourth spacewalk for Koch, the first for Meir, and the first all-female spacewalk in human history.  The first woman to walk in space was Svetlana Savitskaya in 1984.  Koch (red stripe) and Meir are pictured hard at work on the P6 Truss, with solar panels and the darkness of space in the background.  Working over seven hours, the newly installed Battery Charge / Discharge Unit (BCDU) was successfully replaced and, when powered up, operated normally.
Pluto at Night (2019-10-20)
The night side of Pluto spans this shadowy scene, a stunning spacebased view with the Sun 4.9 billion kilometers (almost 4.5 light-hours) behind the dim and distant world. It was captured by far flung New Horizons in July of 2015. The spacecraft was at a range of some 21,000 kilometers from Pluto, about 19 minutes after its closest approach. A denizen of the Kuiper Belt in dramatic silhouette, the image also reveals Pluto's tenuous, surprisingly complex layers of hazy atmosphere. The crescent twilight landscape near the top of the frame includes southern areas of nitrogen ice plains now formally known as Sputnik Planitia and rugged mountains of water-ice in the Norgay Montes.
Night Sky Reflections from the World's Largest Mirror (2019-10-22)
What's being reflected in the world's largest mirror?  Stars, galaxies, and a planet.  Many of these stars are confined to the grand arch that runs across the image, an arch that is the central plane of our home Milky Way Galaxy. Inside the arch is another galaxy -- the neighboring Large Magellanic Cloud (LMC).  Stars that are individually visible include Antares on the far left and Sirius on the far right. The planet Jupiter shines brightly just below Antares. The featured picture is composed of 15 vertical frames taken consecutively over ten minutes from the Uyuni Salt Flat in Bolivia. Uyuni Salt Flat (Salar de Uyuni) is the largest salt flat on Earth and is so large and so extraordinarily flat that, after a rain, it can become the world's largest mirror -- spanning 130 kilometers.  This expansive mirror was captured in early April reflecting each of the galaxies, stars, and planet mentioned above.
Starry Night by Vincent van Gogh (2019-10-23)
The painting Starry Night is one of the most famous icons of the night sky ever created.   The scene was painted by Vincent van Gogh in southern France in 1889.   The swirling style of Starry Night appears, to many, to make the night sky come alive.   Although van Gogh frequently portrayed real settings in his paintings, art historians do not agree on precisely what stars and planets are being depicted in Starry Night.   The style of Starry Night is post-impressionism, a popular painting style at the end of the nineteenth century.  The original Starry Night painting hangs in the Museum of Modern Art in New York City, New York, USA.   New: APOD Read to You by AI
Dark Seahorse in Cepheus (2019-10-24)
Light-years across, this suggestive shape known as the Seahorse Nebula appears in silhouette against a rich, luminous background of stars. Seen toward the royal northern constellation of Cepheus, the dusty, obscuring clouds are part of a Milky Way molecular cloud some 1,200 light-years distant. It is also listed as Barnard 150 (B150), one of 182 dark markings of the sky cataloged in the early 20th century by astronomer E. E. Barnard. Packs of low mass stars are forming within from collapsing cores only visible at long infrared wavelengths. Still, colorful stars in Cepheus add to the pretty, galactic skyscape.
The Ghosts of Cassiopeia (2019-10-25)
These bright rims and flowing shapes look ghostly on a cosmic scale. A telescopic view toward the constellation Cassiopeia, the colorful skyscape features swept-back, comet-shaped clouds IC 59 (left) and IC 63. About 600 light-years distant, the clouds aren't actually ghosts. They are slowly disappearing though, under the influence of energetic radiation from hot,luminous star gamma Cas. Gamma Cas is physically located only 3 to 4 light-years from the nebulae, the bright star just above and left in the frame. Slightly closer to gamma Cas, IC 63 is dominated by red H-alpha light emitted as hydrogen atoms ionized by the star's ultraviolet radiation recombine with electrons. Farther from the star, IC 59 shows proportionally less H-alpha emission but more of the characteristic blue tint of dust reflected star light. The field of view spans over 1 degree or 10 light-years at the estimated distance of gamma Cas and friends.
Gravity's Grin (2019-10-26)
Albert Einstein's general theory of relativity, published over 100 years ago, predicted the phenomenon of gravitational lensing. And that's what gives these distant galaxies such a whimsical appearance, seen through the looking glass of X-ray and optical image data from the Chandra and Hubble space telescopes. Nicknamed the Cheshire Cat galaxy group, the group's two large elliptical galaxies are suggestively framed by arcs. The arcs are optical images of distant background galaxies lensed by the foreground group's total distribution of gravitational mass. Of course, that gravitational mass is dominated by dark matter. The two large elliptical "eye" galaxies represent the brightest members of their own galaxy groups which are merging. Their relative collisional speed of nearly 1,350 kilometers/second heats gas to millions of degrees producing the X-ray glow shown in purple hues. Curiouser about galaxy group mergers? The Cheshire Cat group grins in the constellation Ursa Major, some 4.6 billion light-years away.
Ghost Aurora over Canada (2019-10-27)
What does this aurora look like to you? While braving the cold to watch the skies above northern Canada early one morning in 2013, a most unusual aurora appeared.  The aurora definitely appeared to be shaped like something , but what? Two ghostly possibilities recorded by the astrophotographer were "witch" and "goddess of dawn", but please feel free to suggest your own Halloween-enhanced impressions. Regardless of fantastical pareidolic interpretations, the pictured aurora had a typical green color and was surely caused by the scientifically commonplace action of high energy particles from space interacting with oxygen in Earth's upper atmosphere.  In the image foreground, at the bottom, is a frozen Alexandra Falls, while evergreen trees cross the middle.
The Space Station Crosses a Spotless Sun (2019-10-28)
Typically, the International Space Station is visible only at night.  Slowly drifting across the night sky as it orbits the Earth, the International Space Station (ISS) can be seen as a bright spot about once a month from many locations.  The ISS is then visible only just after sunset or just before sunrise because it shines by reflected sunlight -- once the ISS enters the Earth's shadow, it will drop out of sight. The only occasion when the ISS is visible during the day is when it passes right in front of the Sun. Then, it passes so quickly that only cameras taking short exposures can visually freeze the ISS's silhouette onto the background Sun. The featured picture did exactly that -- it is actually a series of images taken a month ago from Santa Fe, Argentina with perfect timing.  This image series was later combined with a separate image highlighting the texture of the spotless Sun, and an image bringing up the Sun's prominences around the edge. At an unusually low Solar Minimum, the Sun has gone without sunspots now for most of 2019.    Follow APOD in English on: Instagram, Facebook,  Reddit, or Twitter
Curiosity Rover Finds a Clay Cache on Mars (2019-10-29)
Why is there clay on Mars? On Earth, clay can form at the bottom of a peaceful lake when specific minerals trap water.  At the pictured site on Mars, the robotic rover Curiosity drilled into two rocks and found the highest concentration of clay yet.  The clay cache is considered addition evidence that Gale Crater once held water in the distant past.  Pictured, 57 images taken by Curiosity have been combined into a selfie. The images were taken by a camera at the end of its robotic arm. Many details of the car-sized rover are visible, including its rugged wheels, numerous scientific instruments, and a high mast that contains camera "eyes", one of which can shoot out an infrared laser beam.  Curiosity continues to roll around and up Mount Sharp -- in the center of Gale Crater -- in a search for new clues about the ancient history of Mars and whether or not the red planet once had conditions that could support life.
M42: Inside the Orion Nebula (2019-10-30)
The Great Nebula in Orion, an immense, nearby starbirth region, is probably the most famous of all astronomical nebulas.  Here, glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud only 1500 light-years away.  In the featured deep image in assigned colors highlighted by emission in oxygen and hydrogen, wisps and sheets of dust and gas are particularly evident.  The Great Nebula in Orion can be found with the unaided eye near the easily identifiable belt of three stars in the popular constellation Orion.  In addition to housing a bright open cluster of stars known as the Trapezium, the Orion Nebula contains many stellar nurseries.   These nurseries contain much hydrogen gas, hot young stars, proplyds, and stellar jets spewing material at high speeds.  Also known as M42, the Orion Nebula spans about 40 light years and is located in the same spiral arm of our Galaxy as the Sun.
The Ghostly Veil Nebula (2019-10-31)
A ghostly visage on a cosmic scale, these remains of shocked, glowing gas haunt planet Earth's sky toward the constellation of Cygnus and form the Veil Nebula. The nebula itself is a large supernova remnant, an expanding cloud born of the death explosion of a massive star. Light from the original supernova explosion likely reached Earth over 5,000 years ago. Also known as the Cygnus Loop, the Veil Nebula now spans nearly 3 degrees or about 6 times the diameter of the full Moon. That translates to over 70 light-years at its estimated distance of 1,500 light-years. In fact, the Veil is so large its brighter parts are recognized as separate nebulae, including The Witch's Broom (NGC 6960) below and right of center. At the top left you can find the Spectre of IC 1340. Happy Halloween!
The Day After Mars (2019-11-01)
October 31, 1938 was the day after Martians encountered planet Earth, and everything was calm. Reports of the invasion were revealed to be part of a Halloween radio drama, the now famous broadcast based on H.G. Wells' scifi novel War of the Worlds. On Mars October 20, 2014 was calm too, the day after its close encounter with Comet Siding Spring (C/2013 A1). Not a hoax, this comet really did come within 86,700 miles or so of Mars, about 1/3 the Earth-Moon distance. Earth's spacecraft and rovers in Mars orbit and on the surface reported no ill effects though, and had a ringside seat as a visitor from the outer solar system passed by. Spanning over 2 degrees against stars of the constellation Ophiuchus, this colorful telescopic snapshot captures our view of Mars on the day after. Bluish star 51 Ophiuchi is at the upper right and the comet is just emerging from the Red Planet's bright glare.
Inside the Flame Nebula (2019-11-02)
The Flame Nebula stands out in this optical image of the dusty, crowded star forming regions toward Orion's belt, a mere 1,400 light-years away. X-ray data from the Chandra Observatory and infrared images from the Spitzer Space Telescope can take you inside the glowing gas and obscuring dust clouds though. Swiping your cursor (or clicking the image) will reveal many stars of the recently formed, embedded cluster NGC 2024, ranging in age from 200,000 years to 1.5 million years young. The X-ray/infrared composite image overlay spans about 15 light-years across the Flame's center. The X-ray/infrared data also indicate that the youngest stars are concentrated near the middle of the Flame Nebula cluster. That's the opposite of the simplest models of star formation for the stellar nursery that predict star formation begins in the denser center of a molecular cloud core. The result requires a more complex model; perhaps star formation continues longer in the center, or older stars are ejected from the center due to subcluster mergers.
Daphnis and the Rings of Saturn (2019-11-03)
What's happening to the rings of Saturn? A little moon making big waves. The moon is 8-kilometer Daphnis and it is making waves in the Keeler Gap of Saturn's rings using just its gravity -- as it bobs up and down, in and out.  The featured image is a colored and more detailed version of a previously released images taken in 2017 by the robotic Cassini spacecraft during one of its Grand Finale orbits. Daphnis can be seen on the far right, sporting ridges likely accumulated from ring particles.  Daphnis was discovered in Cassini images in 2005 and raised mounds of ring particles so high in 2009 -- during Saturn's equinox when the ring plane pointed directly at the Sun -- that they cast notable shadows.
Near the Center of the Lagoon Nebula (2019-11-04)
Stars are battling gas and dust in the Lagoon Nebula but the photographers are winning. Also known as M8, this photogenic nebula is visible even without binoculars towards the constellation of the Archer (Sagittarius). The energetic processes of star formation create not only the colors but the chaos. The glowing gas results from high-energy starlight striking interstellar hydrogen gas and trace amounts of sulfur, and oxygen gases. The dark dust filaments that lace M8 were created in the atmospheres of cool giant stars and in the debris from supernovae explosions. The light from M8 we see today left about 5,000 years ago. Light takes about 50 years to cross this section of M8.
Spiral Galaxies Spinning Super-Fast (2019-11-05)
Why are these galaxies spinning so fast?  If you estimated each spiral's mass by how much light it emits, their fast rotations should break them apart.  The leading hypothesis as to why these galaxies don't break apart is dark matter -- mass so dark we can't see it. But these galaxies are even out-spinning this break-up limit -- they are the fastest rotating disk galaxies known.  It is therefore further hypothesized that their dark matter halos are so massive -- and their spins so fast -- that it is harder for them to form stars than regular spirals. If so, then these galaxies may be among the most massive spirals possible. Further study of surprising super-spirals like these will continue, likely including observations taken by NASA's James Webb Space Telescope scheduled for launch in 2021.
21st Century M101 (2019-11-06)
One of the last entries in Charles Messier's famous catalog, big, beautiful spiral galaxy M101 is definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way Galaxy. M101 was also one of the original spiral nebulae observed with Lord Rosse's large 19th century telescope, the Leviathan of Parsonstown. In contrast, this multiwavelength view of the large island universe is a composite of images recorded by space-based telescopes in the 21st century. Color coded from X-rays to infrared wavelengths (high to low energies), the image data was taken from the Chandra X-ray Observatory (purple), the Galaxy Evolution Explorer (blue), Hubble Space Telescope(yellow), and the Spitzer Space Telescope(red). While the X-ray data trace the location of multimillion degree gas around M101's exploded stars and neutron star and black hole binary star systems, the lower energy data follow the stars and dust that define M101's grand spiral arms. Also known as the Pinwheel Galaxy, M101 lies within the boundaries of the northern constellation Ursa Major, about 25 million light-years away.
Messier 45: The Daughters of Atlas and Pleione (2019-11-07)
Hurtling through a cosmic dust cloud a mere 400 light-years away, the lovely Pleiades or Seven Sisters open star cluster is well-known for its striking blue reflection nebulae. It lies in the night sky toward the constellation Taurus and the Orion Arm of our Milky Way Galaxy. The sister stars and cosmic dust cloud are not related though, they just happen to be passing through the same region of space. Known since antiquity as a compact grouping of stars, Galileo first sketched the star cluster viewed through his telescope with stars too faint to be seen by eye.  Charles Messier recorded the position of the cluster as the 45th entry in his famous catalog of things which are not comets. In Greek myth, the Pleiades were seven daughters of the astronomical titan Atlas and sea-nymph Pleione. Their parents names are included in the cluster's nine brightest stars. This deep and wide telescopic image spans over 20 light-years across the Pleides star cluster.
NGC 3572 and the Southern Tadpoles (2019-11-08)
This cosmic skyscape features glowing gas and dark dust clouds along side the young stars of NGC 3572. A beautiful emission nebula and star cluster in far southern skies, the region is often overlooked by astroimagers in favor of its brighter neighbor, the nearby Carina Nebula. Stars from NGC 3572 are toward the upper left in the telescopic frame that would measure about 100 light-years across at the cluster's estimated distant of 9,000 light-years. The visible interstellar gas and dust is part of the star cluster's natal molecular cloud. Dense streamers of material within the nebula, eroded by stellar winds and radiation, clearly trail away from the energetic young stars. They are likely sites of ongoing star formation with shapes reminiscent of the cosmic Tadpoles of IC 410 better known to northern skygazers.  In the coming tens to hundreds of millions of years, gas and stars in the cluster will be dispersed though, by gravitational tides and by violent supernova explosions that end the short lives of the massive cluster stars.
Saturn the Giant (2019-11-09)
On May 25, 1961 U.S. president John Kennedy announced the goal of landing astronauts on the Moon by the end of the decade. By November 9, 1967 this Saturn V rocket was ready for launch and the first full test of its capabilities on the Apollo 4 mission. Its development directed by rocket pioneer Wernher Von Braun, the three stage Saturn V stood over 36 stories tall. It had a cluster of five first stage engines fueled by liquid oxygen and kerosene which together were capable of producing 7.9 million pounds of thrust. Giant Saturn V rockets ultimately hurled nine Apollo missions to the Moon and back again with six landing on the lunar surface. The first landing mission, Apollo 11, achieved Kennedy's goal on July 20, 1969.  Watch: the November 11 Transit of Mercury from Earth or from Space.
A Mercury Transit Sequence (2019-11-10)
Tomorrow -- Monday --  Mercury will cross the face of the Sun, as seen from Earth. Called a transit, the last time this happened was in 2016.  Because the plane of Mercury's orbit is not exactly coincident with the plane of Earth's orbit, Mercury usually appears to pass over or under the Sun.  The featured time-lapse sequence, superimposed on a single frame, was taken from a balcony in Belgium shows the entire  transit of 2003 May 7.  That solar crossing lasted over five hours, so that the above 23 images were taken roughly 15 minutes apart.  The north pole of the Sun, the Earth's orbit, and Mercury's orbit, although all different, all occur in directions slightly above the left of the image. Near the center and on the far right, sunspots are visible. After Monday, the next transit of Mercury will occur in 2032.   Watch: the November 11 Transit of Mercury from Earth or from Space.