omnianasa/nasa-apod-metadata huggingface dataset:
A Horizon with Blue and Red (2017-12-05)
What's happening on the horizon? The horizon itself, past a spinach field in Guatemala, shows not only trees but a large volcano: the Volc�n de Fuego (Volcano of Fire). The red glow at the top of the volcano is hot lava. But your eye may also be drawn to the blue circle above the horizon on the left. This circle surrounds the Moon and, together with other colors, is called a corona. A corona is caused by diffraction of light -- here moonlight -- by small water droplets in the Earth's intervening atmosphere. A break in the clouds on the right shows stars and even the planet Saturn far beyond the volcano.  Although Volc�n de Fuego frequently undergoes low-level activity, the astrophotographer considered himself lucky to capture the scene just during an explosive eruption in late September.    Follow APOD on: Facebook,  Google Plus,  Instagram, or Twitter
HH 666: Carina Dust Pillar with Jet (2017-12-06)
To some, it may look like a beehive harboring an evil bee. In reality, the featured Hubble image captures a cosmic pillar of dust, two-light years long, inside of which is Herbig-Haro 666 -- a young star emitting powerful jets. The structure lies within one of our galaxy's largest star forming regions, the Carina Nebula, shining in southern skies at a distance of about 7,500 light-years.  The pillar's layered outline are shaped by the winds and radiation of Carina's young, hot, massive stars, some of which are still forming inside the nebula.  A dust-penetrating view in infrared light better shows the two, narrow, energetic jets blasting outward from a still hidden infant star.   Open Science: Browse 1,500+ codes in the Astrophysics Source Code Library
All the Eclipses of 2017 (2017-12-07)
As seen from planet Earth, all the lunar and solar eclipses of 2017 are represented at the same scale in these four panels. The year's celestial shadow play was followed through four different countries by one adventurous eclipse chaser. To kick off the eclipse season, at top left February's Full Moon was captured from the Czech Republic. Its subtle shading, a penumbral lunar eclipse, is due to Earth's lighter outer shadow. Later that month the New Moon at top right was surrounded by a ring of fire, recorded on film from Argentina near the midpoint of striking annular solar eclipse. The August eclipse pairing below finds the Earth's dark umbral shadow in a partial eclipse from Germany at left, and the vibrant solar corona surrounding a totally eclipsed Sun from the western USA. If you're keeping score, the Saros numbers (eclipse cycles) for all the 2017 eclipses are at bottom left in each panel.
Alpine Superga Moonset (2017-12-08)
December's Full Moon phase occurred near perigee, the closest point in its orbit around our fair planet. Big and bright, the fully illuminated lunar disk sets over rugged mountains in this early morningscape from Turin, Italy. Captured just before sunrise on the opposite horizon, scattered sunlight near the edge of Earth's shadow provides the beautiful reddish glow of the alpine peaks. Hills in the foreground are still in shadow. But the scattered sunlight just illuminates the dome and towers of Turin's historic Basilica of Superga on a hilltop near the lower right in the telephoto frame.
Stardust in Aries (2017-12-09)
This composition in stardust covers over 8 degrees on the northern sky. The mosaicked field of view is west of the familiar Pleiades star cluster, toward the zodiacal constellation Aries and the plane of our Milky Way Galaxy. At right in the deep skyscape is bluish Epsilon Arietis, a star visible to the naked-eye and about 330 light-years away. Reflecting starlight in the region, dusty nebulae LBN762, LBN753, and LBN743 sprawl left to right across the field, but are likely some 1,000 light-years away. At that estimated distance, the cosmic canvas is over 140 light-years across. Near the edge of a large molecular cloud, their dark interiors can hide newly formed stars and young stellar objects or protostars from prying optical telescopes. Collapsing due to self-gravity, the protostars form around dense cores embedded in the molecular cloud.
In Green Company: Aurora over Norway (2017-12-10)
Raise your arms if you see an aurora. With those instructions, two nights went by with, well, clouds -- mostly. On the third night of returning to same peaks, though, the sky not only cleared up but lit up with a spectacular auroral display. Arms went high in the air, patience and experience paid off, and the creative featured image was captured as a composite from three separate exposures. The setting is a summit of the Austnesfjorden fjord close to the town of Svolvear on the Lofoten islands in northern Norway. The time was early 2014. Although our Sun is nearing Solar Minimum and hence showing relatively little surface activity, holes in the upper corona have provided some nice auroral displays over the last few months.   Follow APOD on: Facebook,  Google Plus,  Instagram, Twitter or Snapchat
Highlights of the Winter Sky (2017-12-12)
What's up in the sky this winter?  The featured graphic gives a few highlights for Earth's northern hemisphere.  Viewed as a clock face centered at the bottom, early winter sky events fan out toward the left, while late winter events are projected toward the right.  Objects relatively close to Earth are illustrated, in general, as nearer to the cartoon figure with the telescope at the bottom center -- although almost everything pictured can be seen without a telescope.  Highlights of this winter's sky include the Geminids meteor shower peaking this week, the constellation of Orion becoming notable in the evening sky, and many planets being visible before sunrise in February.  As true in every season, the International Space Station (ISS) can be sometimes be found drifting across your sky if you know just when and where to look.
Meteors over Inner Mongolia (2017-12-13)
Did you ever get caught in a meteor shower? If yes, then every minute or so the sky sparked with fleeting flashes of light. This was the fate of the pictured astrophotographer during last year's Perseids meteor shower. During the featured three-hour image composite, about 90 Perseids rained down above Lake Duolun of Inner Mongolia, China. If you trace back the meteor streaks, you will find that most of them appear to radiate from a single constellation -- in this case Perseus. In fact, you can even tell which meteors are not Perseids because they track differently. Tonight promises to be another good night to get caught in a meteor shower because it is the peak for the Geminids. Gemini, the shower radiant, should rise shortly after sunset and be visible most of the night.   Free APOD Lectures: January 5 in NYC & January 9 in DC
Geminids of the North (2017-12-15)
rth's annual Geminid meteor shower did not disappoint as our fair planet plowed through dust from active asteroid 3200 Phaethon. Captured in this northern hemisphere nightscape, the meteors stream away from the shower's radiant in Gemini. To create the image, 37 individual frames recording meteor streaks were taken over period of 8.5 hours during the night of December 12/13. In the final composite they were selected and registered against the starry sky above a radio telescope dish of MUSER, a solar-dedicated radio telescope array at astronomically-named Mingantu Station in Inner Mongolia, China, about 400 kilometers from Beijing. Sirius, alpha star of Canis Major, shines brightly just above the radio dish and the Milky Way stretches toward the zenith. Yellowish Betelgeuse is a standout in Orion to the right of the northern Milky Way. The shower's radiant is at top left, high above the horizon near Castor and Pollux the twin stars of Gemini. The radiant effect is due to perspective as the parallel meteor tracks appear to converge in the distance.  Gemini's meteors enter Earth's atmosphere traveling at about 22 kilometers per second.   Submitted to APOD: Best images (so far) of the Geminid Meteor Shower 2017.
A Wintry Shower (2017-12-16)
Four Geminids flash through northern skies in this wintry night skyscape. The bright fireball and 3 fainter meteors were captured in a single 10 second exposure, near the peak of December's Geminid meteor shower. Reflecting the fireball's greenish light, a partially frozen Lake Edith in Alberta Canada's Jasper National Park lies in the foreground, with the Canadian Rocky Mountains ranging along the northern horizon. Of course, the glacial lake is cold even in summer. But photographer Jack Fusco reports that he experienced -9 degree C temperatures that night while enjoying one of the most active meteor showers he's ever seen.
The Einstein Cross Gravitational Lens (2017-12-17)
Most galaxies have a single nucleus -- does this galaxy have four?  The strange answer leads astronomers to conclude that the nucleus of the surrounding galaxy is not even visible in this image.  The central cloverleaf is rather light emitted from a background quasar.  The gravitational field of the visible foreground galaxy breaks light from this distant quasar into four distinct images.  The quasar must be properly aligned behind the center of a massive galaxy for a mirage like this to be evident.  The general effect is known as gravitational lensing, and this specific case is known as the Einstein Cross.  Stranger still, the images of the Einstein Cross vary in relative brightness, enhanced occasionally by the additional gravitational microlensing effect of specific stars in the foreground galaxy.     Free Download: The 2018 APOD Calendar
The Kepler-90 Planetary System (2017-12-18)
Do other stars have planetary systems like our own? Yes -- one such system is Kepler-90. Cataloged by the orbiting Kepler satellite, an eighth planet has now been discovered giving Kepler-90 the same number of known planets as our Solar System. Similarities between Kepler-90 and our system include a G-type star comparable to our Sun, rocky planets comparable to our Earth, and large planets comparable in size to Jupiter and Saturn. Differences include that all of the known Kepler-90 planets orbit relatively close in -- closer than Earth's orbit around the Sun -- making them possibly too hot to harbor life. However, observations over longer time periods may discover cooler planets further out. Kepler-90 lies about 2,500 light years away, and at magnitude 14 is visible with a medium-sized telescope toward the constellation of the Dragon (Draco).  Exoplanet-finding missions planned for launch in the next decade include TESS, JWST, WFIRST, and PLATO.
The Spiral North Pole of Mars (2017-12-19)
Why is there a spiral around the North Pole of Mars?  Each winter this pole develops a new outer layer about one meter thick composed of carbon dioxide frozen out of the thin Martian atmosphere.  This fresh layer is deposited on a water-ice layer that exists year round.  Strong winds blow down from above the cap's center and swirl due to the spin of the red planet -- contributing to Planum Boreum's spiral structure.  The featured image is a perspective mosaic generated earlier this year from numerous images taken by ESA's Mars Express and elevations extracted from the laser altimeter aboard NASA's Mars Global Surveyor mission.  New missions to Mars planned in the next few years include Insight with plans to drill into Mars, and ExoMars and the Mars 2020 Rover with plans to search for signs of microscopic Martian life -- past and present.   Free APOD Lectures: January 5 in NYC & January 9 in DC
Solstice Sun and Milky Way (2017-12-21)
Welcome to December's solstice, first day of winter in the north and summer for the southern hemisphere. Astronomical markers of the seasons, solstice and equinox dates are based on the Sun's place in its annual journey along the ecliptic, through planet Earth's sky. At this solstice, the Sun reaches its maximum southern declination of -23.5 degrees today at 16:28 UTC, while its right ascension coordinate on the celestial sphere is 18 hours. That puts the Sun in the constellation Sagittarius in a direction near the center of our Milky Way galaxy. In fact, if you could see today's Solstice Sun against faint background stars and nebulae (that's really hard to do, especially in the daytime ...) your view might look something like this composited panorama. To make it, images of our fair galaxy were taken under dark Namibian night skies, then stitched together in a panoramic view. From a snapshot made on December 21, 2015, the Sun was digitally overlayed as a brilliant star at today's northern winter solstice position, close to the center of the Milky Way.
Gemini's Meteors (2017-12-22)
From dark skies above Heilongjiang province in northeastern China, meteors rain down on a wintry landscape in this beautiful composited night scene. The 48 meteors are part of last week's annual Geminid meteor shower. Despite temperatures of -28 degrees C, all were recorded in camera exposures made during the peak hour of the celestial spectacle. They stream away from the shower's radiant high above the horizon near the two bright stars of the zodiacal constellation of the Twins. A very active shower, this year the December 13-14 peak of the Geminids arrived just before the December 16 closest approach of asteroid 3200 Phaethon to planet Earth. Mysterious 3200 Phaethon is the Geminid shower's likely parent body.
Phaethon's Brood (2017-12-23)
Based on its well-measured orbit, 3200 Phaethon (sounds like FAY-eh-thon) is recognized as the source of the meteroid stream responsible for the annual Geminid meteor shower. Even though most meteor showers' parents are comets, 3200 Phaethon is a known and closely tracked near-Earth asteroid with a 1.4 year orbital period. Rocky and sun-baked, its perihelion or closest approach to the Sun is well within the orbit of innermost planet Mercury. In this telescopic field of view, the asteroid's rapid motion against faint background stars of the heroic constellation Perseus left a short trail during the two minute total exposure time. The parallel streaks of its meteoric children flashed much more quickly across the scene. The family portrait was recorded near the Geminid meteor shower's very active peak on December 13. That was just before 3200 Phaethon's historic December 16 closest approach to planet Earth.   Gallery: Images from yesterday's photogenic SpaceX launch in California
SpaceX Rocket Launch Plume over California (2017-12-24)
What's happened to the sky? On Friday, the photogenic launch plume from a SpaceX rocket launch created quite a spectacle over parts of southern California and Arizona.  Looking at times like a giant space fish, the impressive rocket launch from Vandenberg Air Force Base near Lompoc, California, was so bright because it was backlit by the setting Sun. Lifting off during a minuscule one-second launch window, the Falcon 9 rocket successfully delivered to low Earth orbit ten Iridium NEXT satellites that are part of a developing global communications network. The plume from the first stage is seen on the right, while the soaring upper stage rocket is seen at the apex of the plume toward the left. Several good videos of the launch were taken.  The featured image was captured from Orange County, California, in a 2.5 second duration exposure.   Gallery: More images of the SpaceX launch
Fireball in the Arctic (2017-12-25)
Something very bright suddenly lit up the arctic -- what was it? The original idea was to take a series of aurora images that could be made into a time-lapse video.  But when night suddenly turned into day, the astrophotographer quickly realized that he was seeing something even more spectacular. Moving through the sky -- in front of the Big Dipper no less -- was a Geminid meteor so bright it could be called a fireball. The meteor brightened and flashed for several seconds as it went.  By a stroke of good fortune, the aurora camera was able to capture the whole track. Taken the night after the Geminids Meteor Shower peaked, the astrophotographer's location was near Lovozero Lake in Murmansk, Russia, just north of the Arctic Circle.   Free APOD Lectures: January 5 in NYC & January 9 in DC
Grand Spiral Galaxy NGC 1232 (2017-12-26)
Galaxies are fascinating not only for what is visible, but for what is invisible. Grand spiral galaxy NGC 1232, captured in detail by one of the Very Large Telescopes, is a good example.  The visible is dominated by millions of bright stars and dark dust, caught up in a gravitational swirl of spiral arms revolving about the center. Open clusters containing bright blue stars can be seen sprinkled along these spiral arms, while dark lanes of dense interstellar dust can be seen sprinkled between them. Less visible, but detectable, are billions of dim normal stars and vast tracts of interstellar gas, together wielding such high mass that they dominate the dynamics of the inner galaxy.  Leading theories indicate that even greater amounts of matter are invisible, in a form we don't yet know. This pervasive dark matter is postulated, in part, to explain the motions of the visible matter in the outer regions of galaxies.    Free APOD Lectures: January 5 in NYC & January 9 in DC
The Horsehead Nebula (2017-12-27)
One of the most identifiable nebulae in the sky, the Horsehead Nebula in Orion, is part of a large, dark, molecular cloud.  Also known as Barnard 33, the unusual shape was first discovered on a photographic plate in the late 1800s.  The red glow originates from hydrogen gas predominantly behind the nebula, ionized by the nearby bright star Sigma Orionis.  The darkness of the Horsehead is caused mostly by thick dust, although the lower part of the Horsehead's neck casts a shadow to the left.  Streams of gas leaving the nebula are funneled by a strong magnetic field.  Bright spots in the Horsehead Nebula's base are young stars just in the process of forming.  Light takes about 1,500 years to reach us from the Horsehead Nebula.  The featured image was taken with the large 3.6-m Canada-France-Hawaii Telescope in Hawaii, USA.   Free APOD Lectures: January 5 in NYC & January 9 in DC
Recycling Cassiopeia A (2017-12-28)
Massive stars in our Milky Way Galaxy live spectacular lives.  Collapsing from vast cosmic clouds, their nuclear furnaces ignite and create heavy elements in their cores. After a few million years, the enriched material is blasted back into interstellar space where star formation can begin anew. The expanding debris cloud known as Cassiopeia A is an example of this final phase of the stellar life cycle. Light from the explosion which created this supernova remnant would have been first seen in planet Earth's sky about 350 years ago, although it took that light about 11,000 years to reach us. This false-color Chandra X-ray Observatory image shows the still hot filaments and knots in the Cassiopeia A remnant. High-energy emission from specific elements has been color coded, silicon in red, sulfur in yellow, calcium in green and iron in purple, to help astronomers explore the recycling of our galaxy's star stuff - Still expanding, the blast wave is seen as the blue outer ring. The sharp X-ray image, spans about 30 light-years at the estimated distance of Cassiopeia A. The bright speck near the center is a neutron star, the incredibly dense, collapsed remains of the massive stellar core.
M78 Wide Field (2017-12-29)
Interstellar dust clouds and glowing nebulae abound in the fertile constellation of Orion. One of the brightest, M78, is centered in this colorful, wide field view, covering an area north of Orion's belt. At a distance of about 1,500 light-years, the bluish reflection nebula is around 5 light-years across. Its tint is due to dust preferentially reflecting the blue light of hot, young stars. Reflection nebula NGC 2071 is just to the left of M78. To the right, and much more compact in appearance, the intriguing McNeil's Nebula is a recently recognized variable nebula associated with a young sun-like star. Deeper red flecks of emission from Herbig-Haro objects, energetic jets from stars in the process of formation, stand out against the dark dust lanes. The exposure also brings out the region's fainter pervasive glow of atomic hydrogen gas.
Apollo 17 VIP Site Anaglyph (2017-12-30)
Get out your red/blue glasses and check out this stereo scene from Taurus-Littrow valley on the Moon! The color anaglyph features a detailed 3D view of Apollo 17's Lunar Rover in the foreground -- behind it lies the Lunar Module and distant lunar hills. Because the world was going to be able to watch the Lunar Module's ascent stage liftoff via the rover's TV camera, this parking place was also known as the VIP Site. In December of 1972, Apollo 17 astronauts Eugene Cernan and Harrison Schmitt spent about 75 hours on the Moon, while colleague Ronald Evans orbited overhead. The crew returned with 110 kilograms of rock and soil samples, more than from any of the other lunar landing sites. Cernan and Schmitt are still the last to walk (or drive) on the Moon.
To Fly Free in Space (2017-12-31)
What would it be like to fly free in space?  At about 100 meters from the cargo bay of the space shuttle Challenger, Bruce McCandless II was living the dream -- floating farther out than anyone had ever been before.  Guided by a Manned Maneuvering Unit (MMU), astronaut McCandless, pictured, was floating free in space. McCandless and fellow NASA astronaut Robert Stewart were the first to experience such an "untethered space walk" during Space Shuttle mission 41-B in 1984.  The MMU worked by shooting jets of nitrogen and was used to help deploy and retrieve satellites.  With a mass over 140 kilograms, an MMU is heavy on Earth, but, like everything, is weightless when drifting in orbit. The MMU was replaced with the SAFER backpack propulsion unit.   Memorial: Astronaut Bruce McCandless II Dies at 80
Unexpected X-Rays from Perseus Galaxy Cluster (2018-01-02)
Why does the Perseus galaxy cluster shine so strangely in one specific color of X-rays? No one is sure, but a much-debated hypothesis holds that these X-rays are a clue to the long-sought identity of dark matter. At the center of this mystery is a 3.5 Kilo-electronvolt (KeV) X-ray color that appears to glow excessively only when regions well outside the cluster center are observed, whereas the area directly surrounding a likely central supermassive black hole is actually deficient in 3.5 keV X-rays. One proposed resolution -- quite controversial -- is that something never seen before might be present: fluorescent dark matter (FDM). This form of particle dark matter might be able to absorb 3.5 keV X-radiation.  If operating, FDM, after absorption, might later emit these X-rays from all over the cluster, creating an emission line. However, when seen superposed in front of the central region surrounding the black hole, FDM's absorption would be more prominent, creating an absorption line.  Pictured, a composite image of the Perseus galaxy cluster shows visible and radio light in red, and X-ray light from the Earth-orbiting Chandra Observatory in blue.    Free APOD Lectures: January 5 in NYC & January 9 in DC
The Helix Nebula from CFHT (2018-01-03)
Will our Sun look like this one day?  The Helix Nebula is one of brightest and closest examples of a planetary nebula, a gas cloud created at the end of the life of a Sun-like star. The outer gasses of the star expelled into space appear from our vantage point as if we are looking down a helix. The remnant central stellar core, destined to become a white dwarf star, glows in light so energetic it causes the previously expelled gas to fluoresce. The Helix Nebula, given a technical designation of NGC 7293, lies about 700 light-years away towards the constellation of the Water Bearer (Aquarius) and spans about 2.5 light-years. The featured picture was taken with the Canada-France-Hawaii Telescope (CFHT) located atop a dormant volcano in Hawaii, USA. A close-up of the inner edge of the Helix Nebula shows complex gas knots of unknown origin.   Free APOD Lectures: January 5 in NYC & January 9 in DC