omnianasa/nasa-apod-metadata huggingface dataset:
ISS from Wallasey (2019-04-06)
After sunset on March 28, the International Space Station climbed above the western horizon, as seen from Wallasey, England at the mouth of the River Mersey. Still glinting in the sunlight some 400 kilometers above planet Earth, the fast moving ISS was followed by hand with a small backyard telescope and high frame rate digital camera. A total of 2500 frames were recorded during the 7 minute long visible ISS passage and 100 of them captured images of the space station. These are the four best frames showing remarkable details of the ISS in low Earth orbit. Near the peak of its track, about 60 degrees above the horizon, the ISS was brighter than the brightest star in the sky and as close as 468 kilometers to the Wallasey backyard.
A Scorpius Sky Spectacular (2019-04-07)
If Scorpius looked this good to the unaided eye, humans might remember it better.  Scorpius more typically appears as a few bright stars in a well-known but rarely pointed out zodiacal constellation. To get a spectacular image like this, though, one needs a good camera, color filters, and a digital image processor.  To bring out detail, the featured image not only involved long duration exposures taken in several colors, but one exposure in a very specific red color emitted by hydrogen.  The resulting image shows many breathtaking features.  Vertically across the image left is part of the plane of our Milky Way Galaxy.   Visible there are vast clouds of bright stars and long filaments of dark dust.  Jutting out diagonally from the Milky Way in the image center are dark dust bands known as the Dark River.  This river connects to several bright stars on the right that are part of Scorpius' head and claws, and include the bright star Antares.  Above and right of Antares is an even brighter planet: Jupiter. Numerous red emission nebulas and blue reflection nebulas are visible throughout the image. Scorpius appears prominently in southern skies after sunset during the middle of the year.
AZURE Vapor Tracers over Norway (2019-04-08)
What's happening in the sky? The atmosphere over northern Norway appeared quite strange for about 30 minutes last Friday when colorful clouds, dots, and plumes suddenly appeared. The colors were actually created by the NASA-funded Auroral Zone Upwelling Rocket Experiment (AZURE) which dispersed gas tracers to probe winds in Earth's upper atmosphere. AZURE's tracers originated from two short-lived sounding rockets launched from the And�ya Space Center in Norway. The harmless gases, trimethylaluminum and a barium/strontium mixture, were released into the ionosphere at altitudes of 115 and 250 km.  The vapor trails were observed dispersing from several ground stations. Mapping how AZURE's vapors dispersed should increase humanity's understanding of how the solar wind transfers energy to the Earth and powers aurora.
Moon Occults Saturn (2019-04-09)
Sometimes Saturn disappears. It doesn't really go away, though, it just disappears from view when our Moon moves in front.  Such a Saturnian eclipse was visible along a small swath of Earth -- from Brazil to Sri Lanka -- near the end of last month. The featured color image is a digital fusion of the clearest images captured by successive videos of the event taken in red, green, and blue, and taken separately for Saturn and the comparative bright Moon.  The exposures were taken from South Africa just before occultation -- and also just before sunrise. When Saturn re-appeared on the other side of the Moon almost two hours later, the Sun had risen. This year, eclipses of Saturn by the Moon occur almost monthly, but, unfortunately, are visible only to those with the right location and with clear and dark skies.   Follow APOD on Instagram: English or Persian
First Horizon-Scale Image of a Black Hole (2019-04-11)
What does a black hole look like? To find out, radio telescopes from around the Earth coordinated observations of black holes with the largest known event horizons on the sky.  Alone, black holes are just black, but these monster attractors are known to be surrounded by glowing gas.  The first image was released yesterday and resolved the area around the black hole at the center of galaxy M87 on a scale below that expected for its event horizon.  Pictured, the dark central region is not the event horizon, but rather the black hole's shadow -- the central region of emitting gas darkened by the central black hole's gravity. The size and shape of the shadow is determined by bright gas near the event horizon, by strong gravitational lensing deflections, and by the black hole's spin.  In resolving this black hole's shadow, the Event Horizon Telescope (EHT) bolstered evidence that Einstein's gravity works even in extreme regions, and gave clear evidence that M87 has a central spinning black hole of about 6 billion solar masses.  The EHT is not done -- future observations will be geared toward even higher resolution, better tracking of variability, and exploring the immediate vicinity of the black hole in the center of our Milky Way Galaxy.
A Cosmic Rose: The Rosette Nebula in Monoceros (2019-04-12)
The Rosette Nebula, NGC 2237, is not the only cosmic cloud of gas and dust to evoke the imagery of flowers, but it is the most famous.  At the edge of a large molecular cloud in Monoceros some 5,000 light years away, the petals of this cosmic rose are actually a stellar nursery. The lovely, symmetric shape is sculpted by the winds and radiation from its central cluster of hot young, O-type stars. Stars in the energetic cluster, cataloged as NGC 2244, are only a few million years young, while the central cavity in the Rosette Nebula, is about 50 light-years in diameter. The nebula can be seen with a small telescope toward the constellation of Monoceros, the Unicorn. This natural appearing telescopic portrait of the Rosette Nebula was made using broadband and narrowband filters, because sometimes roses aren't red.
Rigil Kentaurus and Sandqvist 169 (2019-04-13)
Rigil Kentaurus is the bright star near the top of this broad southern skyscape. Of course it's probably better known as Alpha Centauri, nearest star system to the Sun. Below it sprawls a dark nebula complex. The obscuring interstellar dust clouds include Sandqvist catalog clouds 169 and 172 in silhouette against the rich starfields along the southern Milky Way. Rigil Kent is a mere 4.37 light-years away, but the dusty dark nebulae lie at the edge of the starforming Circinus-West molecular cloud about 2,500 light-years distant. The wide-field of view spans over 12 degrees (24 full moons) across southern skies.
Enhanced: The Dolphin Cloud on Jupiter (2019-04-15)
Do you see the dolphin-shaped cloud on Jupiter? The cloud was visible last year during perijove 16, the sixteenth time that NASA's robotic spacecraft Juno passed near Jupiter since it arrived in mid-2016.  During each perijove, Juno passes near a slightly different part of Jupiter's cloud tops.  The dolphin shape may be surprising but is not scientifically significant -- clouds on Jupiter and Earth are constantly shifting and can temporarily mimic many familiar shapes. The cloud appears in Jupiter's South Temperate Belt (STB), a band of dark and dropping clouds that rings the planet and also contains Oval BA, dubbed Red Spot Jr.  The featured image was digitally processed to enhance color and contrast.  Juno's next swoop near Jupiter -- perijove 20 -- will occur on late May.
In the Vicinity of the Cone Nebula (2019-04-16)
Strange shapes and textures can be found in neighborhood of the Cone Nebula. The unusual shapes originate from fine interstellar dust reacting in complex ways with the energetic light and hot gas being expelled by the young stars.  The brightest star on the right of the featured picture is S Mon, while the region just below it has been nicknamed the Fox Fur Nebula for its color and structure. The blue glow directly surrounding S Mon results from reflection, where neighboring dust reflects light from the bright star. The red glow that encompasses the whole region results not only from dust reflection but also emission from hydrogen gas ionized by starlight. S Mon is part of a young open cluster of stars named NGC 2264, located about 2500 light years away toward the constellation of the Unicorn (Monoceros).   Even though it points right at S Mon, details of the origin of the mysterious geometric Cone Nebula, visible on the far left, remain a mystery.
Messier 81 (2019-04-17)
One of the brightest galaxies in planet Earth's sky is similar in size to our Milky Way Galaxy: big, beautiful Messier 81. Also known as NGC 3031 or Bode's galaxy for its 18th century discoverer, this grand spiral can be found toward the northern constellation of Ursa Major, the Great Bear. The detailed telescopic view reveals M81's bright yellow nucleus, blue spiral arms, pink starforming regions, and sweeping cosmic dust lanes. Some dust lanes actually run through the galactic disk (left of center), contrary to other prominent spiral features though. The errant dust lanes may be the lingering result of a close encounter between M81 and its smaller companion galaxy, M82. Scrutiny of variable stars in M81 has yielded one of the best determined distances for an external galaxy -- 11.8 million light-years.
The Leo Trio (2019-04-18)
This group is popular in the northern spring. Famous as the Leo Triplet, the three magnificent galaxies gather in one field of view. Crowd pleasers when imaged with even modest telescopes, they can be introduced individually as NGC 3628 (left), M66 (bottom right), and M65 (top). All three are large spiral galaxies but they tend to look dissimilar because their galactic disks are tilted at different angles to our line of sight. NGC 3628, also known as the Hamburger Galaxy, is temptingly seen edge-on, with obscuring dust lanes cutting across its puffy galactic plane. The disks of M66 and M65 are both inclined enough to show off their spiral structure.  Gravitational interactions between galaxies in the group have left telltale signs, including the tidal tails and warped, inflated disk of NGC 3628 and the drawn out spiral arms of M66. This gorgeous view of the region spans almost two degrees (four full moons) on the sky. The field covers about a million light-years at the trio's estimated distance of 30 million light-years. Of course the spiky foreground stars lie within our own Milky Way.
Milky Way in Northern Spring (2019-04-19)
A postcard from planet Earth, this springtime night skyscape looks over Alandan lake in the Alborz mountains. Taken after local midnight on April 17, the central Milky Way is rising over the region's southeast horizon. Its luminous track of stars and nebulae along the plane of our galaxy are reflected in the mirror-like lake.  The brightest celestial beacon mingled with the diffuse galactic starlight is Jupiter. Slightly dimmer, Saturn is below and left just above the mountains. As spring brought leaves to the trees and the galactic center to the northern night the photographer found it also gave frogs their voices, heard like a melody across the calm water.
Falcon Heavy Launch Close Up (2019-04-20)
Twenty seven Merlin rocket engines are firing in this close-up of the launch of a Falcon Heavy rocket. Derived from three Falcon 9 first stage rockets with nine Merlin rocket engines each, the Falcon Heavy left NASA's Kennedy Space Center launch pad 39A on April 11. This second launch of a Falcon Heavy rocket carried the Arabsat 6A communications satellite to space. In February of 2018, the first Falcon Heavy launch carried Starman and a Tesla Roadster. Designed to be reusable, both booster stages and the central core returned safely to planet Earth, the boosters to Cape Canaveral Air Force Station landing zones. The core stage landed off shore on autonomous spaceport drone ship Of Course I Still Love You.
Spiral Aurora over Icelandic Divide (2019-04-21)
Admire the beauty but fear the beast.  The beauty is the aurora overhead, here taking the form of great green spiral, seen between picturesque clouds with the bright Moon to the side and stars in the background.  The beast is the wave of charged particles that creates the aurora but might, one day, impair civilization. In 1859, following notable auroras seen all across the globe, a pulse of charged particles from a coronal mass ejection (CME) associated with a solar flare impacted Earth's magnetosphere so forcefully that they created the Carrington Event. A relatively direct path between the Sun and the Earth might have been cleared by a preceding CME.  What is sure is that the Carrington Event compressed the Earth's magnetic field so violently that currents were created in telegraph wires so great that many wires sparked and gave telegraph operators shocks. Were a Carrington-class event to impact the Earth today, speculation holds that damage might occur to global power grids and electronics on a scale never yet experienced. The featured aurora was imaged in 2016 over Thingvallavatn Lake in Iceland, a lake that partly fills a fault that divides Earth's large Eurasian and North American tectonic plates.   APOD in other languages: Arabic, Catalan, Chinese (Beijing), Chinese (Taiwan), Croatian, Czech, Dutch, German, French, French, Indonesian, Japanese, Korean, Montenegrin, Polish, Russian, Serbian, Slovenian,  Spanish and Ukrainian
Meteors, Comet, and Big Dipper over La Palma (2019-04-23)
Meteor showers are caused by streams of solid particles, dust size and larger, moving as a group through space.  In most cases, the orbits of these meteor streams can be identified with dust expelled from a comet.  When the Earth passes through a stream, the particles leave brilliant trails through the night sky as they disintegrate in Earth's atmosphere.  The meteor paths are all parallel to each other, but, like train tracks, the effect of perspective causes them to appear to originate from a radiant point in the distance.  The featured image composite was taken during January's Quadrantid meteor shower from La Palma, one of Spain's Canary Islands, off the northwest coast of Africa. The Quadrantids radiant is visible just below the handle of the Big Dipper. A careful eye will also discern the faint green coma of Comet Wirtanen.  Tonight is the peak of the modest Lyrid meteor shower, with several meteors per hour visible from dark locations with clear skies.
The Shape of the Southern Crab (2019-04-24)
The symmetric, multi-legged appearance of the Southern Crab Nebula is certainly distinctive. About 7,000 light-years distant toward the southern sky constellation Centaurus, its glowing nested hourglass shapes are produced by the remarkable symbiotic binary star system at its center. The nebula's dramatic stellar duo consists of a hot white dwarf star and cool, pulsating red giant star shedding outer layers that fall onto the smaller, much hotter companion. Embedded in a disk of material, outbursts from the white dwarf cause an outflow of gas driven away both above and below the disk resulting in the bipolar hourglass shapes. The bright central shape is about half a light-year across. This new Hubble Space Telescope image celebrates the 29th anniversary of Hubble's launch on April 24, 1990 on board the Space Shuttle Discovery.
Pan-STARRS Across the Lagoon (2019-04-25)
Ridges of glowing interstellar gas and dark dust clouds inhabit the turbulent, cosmic depths of the Lagoon Nebula. Also known as M8, the bright star forming region is about 5,000 light-years distant. But it still makes for a popular stop on telescopic tours of the constellation Sagittarius, toward the center of our Milky Way Galaxy. Dominated by the telltale red emission of ionized hydrogen atoms recombining with stripped electrons, this stunning view of the Lagoon is over 100 light-years across.  At its center, the bright, compact, hourglass shape is gas ionized and sculpted by energetic radiation and extreme stellar winds from a massive young star. In fact, the many bright stars of open cluster NGC 6530 drift within the nebula, just formed in the Lagoon several million years ago. Broadband image data from Pan-STARRS (Panoramic Survey Telescope & Rapid Response System) was combined with narrowband data from amateur telescopes to create this wide and deep portrait of the Lagoon Nebula.
Southern Cross to Eta Carinae (2019-04-26)
Tracking along the southern Milky Way this beautiful celestial mosaic was recorded under dark Brazilian skies. Spanning some 20 degrees it actually starts with the dark expanse of the Coalsack nebula at the lower left, tucked under an arm of the Southern Cross. That compact constellation is topped by bright yellowish Gamma Crucis, a cool giant star a mere 88 light-years distant. A line from Gamma Crucis through the blue star at the bottom of the cross, Alpha Crucis, points toward the South Celestial Pole. Follow the Milky Way to the right and your gaze will sweep across IC 2948, popularly known as the Running Chicken nebula, before it reaches Eta Carinae and the Carina Nebula near the right edge of the frame. About 200 light-years across, the Carina Nebula is a star forming region much larger than the more northerly stellar nursery the Orion Nebula. The Carina Nebula lies around 7,500 light-years from Earth along the plane of the Milky Way.
The Galaxy, the Jet, and the Black Hole (2019-04-27)
Bright elliptical galaxy Messier 87 (M87) is home to the supermassive black hole captured by planet Earth's Event Horizon Telescope in the first ever image of a black hole. Giant of the Virgo galaxy cluster about 55 million light-years away, M87 is the large galaxy rendered in blue hues in this infrared image from the Spitzer Space telescope.  Though M87 appears mostly featureless and cloud-like, the Spitzer image does record details of relativistic jets blasting from the galaxy's central region. Shown in the inset at top right, the jets themselves span thousands of light-years. The brighter jet seen on the right is approaching and close to our line of sight. Opposite, the shock created by the otherwise unseen receding jet lights up a fainter arc of material. Inset at bottom right, the historic black hole image is shown in context, at the center of giant galaxy and relativistic jets. Completely unresolved in the Spitzer image, the supermassive black hole surrounded by infalling material is the source of the enormous energy driving the relativistic jets from the center of active galaxy M87.
N11: Star Clouds of the LMC (2019-04-29)
Massive stars, abrasive winds, mountains of dust, and energetic light sculpt one of the largest and most picturesque regions of star formation in the Local Group of Galaxies.  Known as N11, the region is visible on the upper right of many images of its home galaxy, the Milky Way neighbor known as the Large Magellanic Clouds (LMC).  The featured image was taken for scientific purposes by the Hubble Space Telescope and reprocessed for artistry by an amateur to win a Hubble's Hidden Treasures competition.  Although the section imaged above is known as NGC 1763, the entire N11 emission nebula is second in LMC size only to the Tarantula Nebula.  Compact globules of dark dust housing emerging young stars are also visible around the image.  A new study of variable stars in the LMC with Hubble has helped to recalibrate the distance scale of the  observable universe, but resulted in a slightly different scale than found using the pervasive cosmic microwave background.   Astrophysicists: Browse 1,900+ codes in the Astrophysics Source Code Library
Meteor Misses Galaxy (2019-04-30)
The galaxy was never in danger. For one thing, the Triangulum galaxy (M33), pictured, is much bigger than the tiny grain of rock at the head of the meteor. For another, the galaxy is much farther away -- in this instance 3 million light years as opposed to only about 0.0003 light seconds.  Even so, the meteor's path took it angularly below the galaxy. Also the wind high in Earth's atmosphere blew the meteor's glowing evaporative molecule train away from the galaxy, in angular projection.  Still, the astrophotographer was quite lucky to capture both a meteor and a galaxy in a single exposure -- which was subsequently added to two other images of M33 to bring up the spiral galaxy's colors.  At the end, the meteor was gone in a second, but the galaxy will last billions of years.    Follow APOD on: Instagram, Facebook,  Reddit, or Twitter
The Cat's Eye Nebula in Optical and X-ray (2019-05-01)
To some it looks like a cat's eye. To others, perhaps like a giant cosmic conch shell.  It is actually one of brightest and most highly detailed planetary nebula known, composed of gas expelled in the brief yet glorious phase near the end of life of a Sun-like star. This nebula's dying central star may have produced the outer circular concentric shells by shrugging off outer layers in a series of regular convulsions. The formation of the beautiful, complex-yet-symmetric inner structures, however, is not well understood. The featured image is a composite of a digitally sharpened Hubble Space Telescope image with X-ray light captured by the orbiting Chandra Observatory.  The exquisite floating space statue spans over half a light-year across. Of course, gazing into this Cat's Eye, humanity may well be seeing the fate of our sun, destined to enter its own planetary nebula phase of evolution ... in about 5 billion years.
Manicouagan Impact Crater from Space (2019-05-02)
Orbiting 400 kilometers above Quebec, Canada, planet Earth, the International Space Station Expedition 59 crew captured this snapshot of the broad St. Lawrence River and curiously circular Lake Manicouagan on April 11. Right of center, the ring-shaped lake is a modern reservoir within the eroded remnant of an ancient 100 kilometer diameter impact crater. The ancient crater is very conspicuous from orbit, a visible reminder that Earth is vulnerable to rocks from space. Over 200 million years old, the Manicouagan crater was likely caused by the impact of a rocky body about 5 kilometers in diameter.  Currently, there is no known asteroid with a significant probability of impacting Earth in the next century.  But a fictional scenario to help practice for an asteroid impact is on going at the 2019 IAA Planetary Defense Conference.
Clouds of the Large Magellanic Cloud (2019-05-03)
The Large Magellanic Cloud (LMC) is an alluring sight in southern skies. But this deep and detailed telescopic view, over 10 months in the making, goes beyond what is visible to most circumnavigators of planet Earth. Spanning over 5 degrees or 10 full moons, the 4x4 panel mosaic was constructed from 3900 frames with a total of 1,060 hours of exposure time in both broadband and narrowband filters. The narrowband filters are designed to transmit only light emitted by sulfur, hydrogen, and oxygen atoms. Ionized by energetic starlight, the atoms emit their characteristic light as electrons are recaptured and the atoms transition to a lower energy state. As a result, in this image the LMC seems covered with its own clouds of ionized gas surrounding its massive, young stars. Sculpted by the strong stellar winds and ultraviolet radiation, the glowing clouds, dominated by emission from hydrogen, are known as H II (ionized hydrogen) regions. Itself composed of many overlapping H II regions, the Tarantula Nebula is the large star forming region at the left. The largest satellite of our Milky Way Galaxy, the LMC is about 15,000 light-years across and lies a mere 160,000 light-years away toward the constellation Dorado.
Saturn and the Da Vinci Glow (2019-05-04)
On February 2nd early morning risers saw Saturn near an old Moon low on the eastern horizon. On that date bright planet, sunlit crescent, and faint lunar night side were captured in this predawn skyscape from Bursa, Turkey. Of course the Moon's ashen glow is earthshine, earthlight reflected from the Moon's night side. A description of earthshine, in terms of sunlight reflected by Earth's oceans illuminating the Moon's dark surface, was written over 500 years ago by Leonardo da Vinci. On May 2nd an old Moon also rose in the predawn twilight. On that date its ashen glow shared the sky with Venus, the brilliant morning star. May 2nd also marked the 500th anniversary of Leonardo's death in 1519.