omnianasa/nasa-apod-metadata huggingface dataset:
Manicouagan Impact Crater from Space (2024-05-25)
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.  Each month, NASA’s Planetary Defense Coordination Office releases an update featuring the most recent figures on near-Earth object close approaches, and other facts about comets and asteroids that could pose a potential impact hazard with Earth.
A Solar Filament Erupts (2024-05-26)
What's happened to our Sun?  Nothing very unusual -- it just threw a filament. Toward the middle of 2012, a long standing solar filament suddenly erupted into space, producing an energetic coronal mass ejection (CME).  The filament had been held up for days by the Sun's ever changing magnetic field and the timing of the eruption was unexpected. Watched closely by the Sun-orbiting Solar Dynamics Observatory, the resulting explosion shot electrons and ions into the Solar System, some of which arrived at Earth three days later and impacted Earth's magnetosphere, causing visible auroras. Loops of plasma surrounding the active region can be seen above the erupting filament in the featured ultraviolet image. Our Sun is nearing the most active time in its 11-year cycle, creating many coronal holes that allow for the ejection of charged particles into space. As before, these charged particles can create auroras.    Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)
Chamaeleon I Molecular Cloud (2024-05-27)
Dark markings and bright nebulae in this telescopic southern sky view are telltale signs of young stars and active star formation. They lie a mere 650 light-years away, at the boundary of the local bubble and the Chamaeleon molecular cloud complex. Regions with young stars identified as dusty reflection nebulae from the 1946 Cederblad catalog include the C-shaped Ced 110 just above and right of center, and bluish Ced 111 below it. Also a standout in the frame, the orange tinted V-shape of the Chamaeleon Infrared Nebula (Cha IRN) was carved by material streaming from a newly formed low-mass star.  The well-composed image spans 1.5 degrees. That's about 17 light-years at the estimated distance of the nearby Chamaeleon I molecular cloud.
Stairway to the Milky Way (2024-05-29)
What happens if you ascend this stairway to the Milky Way? Before answering that, let's understand the beautiful sky you will see.  Most eye-catching is the grand arch of the Milky Way Galaxy, the band that is the central disk of our galaxy which is straight but distorted by the wide-angle nature of this composite image.  Many stars well in front of the Milk Way will be visible, with the bright white star just below the stellar arch being Altair, and the bright blue star above it being Vega.  The air glows green on the left, just above the yellow cloud deck.  The featured image was taken last month on Portugal's Madeira Island in the North Atlantic Ocean.  Oh, and what happens after you reach the top of these stairs and admire the amazing sky is, quite probably, that you then descend down the stairs on the other side.   Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)
A Lunar Corona over Paris (2024-05-30)
Why does a cloudy moon sometimes appear colorful? The effect, called a lunar corona, is created by the quantum mechanical diffraction of light around individual, similarly-sized water droplets in an intervening but mostly-transparent cloud. Since light of different colors has different wavelengths, each color diffracts differently. Lunar coronae are one of the few  quantum mechanical color effects that can be easily seen with the unaided eye.  Solar coronae are also sometimes evident. The featured image was taken last month from Paris, France.  The blue beacon emanating from the Eiffel Tower did not affect the colorful lunar corona.   Portal Universe: Random APOD Generator
The Nebulous Realm of WR 134 (2024-05-31)
Made with narrowband filters, this cosmic snapshot covers a field of view over twice as wide as the full Moon within the boundaries of the constellation Cygnus. It highlights the bright edge of a ring-like nebula traced by the glow of ionized hydrogen and oxygen gas. Embedded in the region's expanse of interstellar clouds, the complex, glowing arcs are sections of shells of material swept up by the wind from Wolf-Rayet star WR 134, brightest star near the center of the frame. Distance estimates put WR 134 about 6,000 light-years away, making the frame over 100 light-years across. Shedding their outer envelopes in powerful stellar winds, massive Wolf-Rayet stars have burned through their nuclear fuel at a prodigious rate and end this final phase of massive star evolution in a spectacular supernova explosion. The stellar winds and final supernova enrich the interstellar material with heavy elements to be incorporated in future generations of stars.
Stereo Helene (2024-06-01)
Get out your red/blue glasses and float next to Helene, small, icy moon of Saturn. Appropriately named, Helene is a Trojan moon, so called because it orbits at a Lagrange point. A Lagrange point is a gravitationally stable position near two massive bodies, in this case Saturn and larger moon Dione. In fact, irregularly shaped ( about 36 by 32 by 30 kilometers) Helene orbits at Dione's leading Lagrange point while brotherly ice moon Polydeuces follows at Dione's trailing Lagrange point. The sharp stereo anaglyph was constructed from two Cassini images captured during a close flyby in 2011. It shows part of the Saturn-facing hemisphere of Helene mottled with craters and gully-like features.
NGC 2403 in Camelopardalis (2024-06-03)
Magnificent island universe NGC 2403 stands within the boundaries of the long-necked constellation Camelopardalis. Some 10 million light-years distant and about 50,000 light-years across, the spiral galaxy also seems to have more than its fair share of giant star forming HII regions, marked by the telltale reddish glow of atomic hydrogen gas. The giant HII regions are energized by clusters of hot, massive stars that explode as bright supernovae at the end of their short and furious lives. A member of the M81 group of galaxies, NGC 2403 closely resembles a galaxy in our own local galaxy group with an abundance of star forming regions, M33, the Triangulum Galaxy. Spiky in appearance, bright stars in this portrait of NGC 2403 are in the foreground, within our own Milky Way. Also in the foreground of the deep, wide-field, telescopic image are the Milky Way's dim and dusty interstellar clouds also known as galactic cirrus or integrated flux nebulae. But faint features that seem to extend from NGC 2403 itself are likely tidal stellar streams drawn out by gravitational interactions with neighboring galaxies.
Comet Pons-Brooks Develops Opposing Tails (2024-06-04)
Why does Comet Pons-Brooks now have tails pointing in opposite directions?  The most spectacular tail is the blue-glowing ion tail that is visible flowing down the image.  The ion tail is pushed directly out from the Sun by the solar wind. On the upper right is the glowing central coma of Comet 12P/Pons–Brooks. Fanning out from the coma, mostly to the left, is the comet's dust tail. Pushed out and slowed down by the pressure of sunlight, the dust tail tends to trail the comet along its orbit and, from some viewing angles, can appear opposite to the ion tail.  The distant, bright star Alpha Leporis is seen at the bottom of the featured image captured last week from Namibia. Two days ago, the comet passed its closest to the Earth and is now best visible from southern skies as it dims and glides back to the outer Solar System.
Shadow of a Martian Robot (2024-06-05)
What if you saw your shadow on Mars and it wasn't human?  Then you might be the Perseverance rover exploring Mars.  Perseverance has been examining the Red Planet since 2021, finding evidence of its complex history of volcanism and ancient flowing water, and sending breathtaking images across the inner Solar System.  Pictured here in February of 2024, Perseverance looks opposite the Sun and across Neretva Vallis in Jezero Crater, with a local hill visible at the top of the frame.  The distinctively non-human shadow of the car-sized rover is visible below center, superposed on scattered rocks.  Perseverance, now working without its flying companion Ingenuity, continues to search Mars for signs of ancient life.
NGC 4565: Galaxy on Edge (2024-06-06)
Magnificent spiral galaxy NGC 4565 is viewed edge-on from planet Earth. Also known as the Needle Galaxy for its narrow profile, bright NGC 4565 is a stop on many telescopic tours of the northern sky, in the faint but well-groomed constellation Coma Berenices. This sharp, colorful image reveals the galaxy's boxy, bulging central core cut by obscuring dust lanes that lace NGC 4565's thin galactic plane. NGC 4565 itself lies about 40 million light-years distant and spans some 100,000 light-years.  Easily spotted with small telescopes, sky enthusiasts consider NGC 4565 to be a prominent celestial masterpiece Messier missed.
SH2-308: The Dolphin Head Nebula (2024-06-07)
Blown by fast winds from a hot, massive star, this cosmic bubble is huge. Cataloged as Sharpless 2-308 it lies some 5,000 light-years away toward the well-trained constellation Canis Major and covers slightly more of the sky than a Full Moon. That corresponds to a diameter of 60 light-years at its estimated distance. The massive star that created the bubble, a Wolf-Rayet star, is the bright one near the center of the nebula. Wolf-Rayet stars have over 20 times the mass of the Sun and are thought to be in a brief, pre-supernova phase of massive star evolution. Fast winds from this Wolf-Rayet star create the bubble-shaped nebula as they sweep up slower moving material from an earlier phase of evolution. The windblown nebula has an age of about 70,000 years. Relatively faint emission captured by narrowband filters in the deep image is dominated by the glow of ionized oxygen atoms mapped to a blue hue. Presenting a mostly harmless outline, SH2-308 is also known as The Dolphin-head Nebula.
Pandora's Cluster of Galaxies (2024-06-08)
This deep field mosaicked image presents a stunning view of galaxy cluster Abell 2744 recorded by the James Webb Space Telescope's NIRCam. Also dubbed Pandora's Cluster, Abell 2744 itself appears to be a ponderous merger of three different massive galaxy clusters. It lies some 3.5 billion light-years away, toward the constellation Sculptor. Dominated by dark matter, the mega-cluster warps and distorts the fabric of spacetime, gravitationally lensing even more distant objects. Redder than the Pandora cluster galaxies many of the lensed sources are very distant galaxies in the early Universe, their lensed images stretched and distorted into arcs. Of course distinctive diffraction spikes mark foreground Milky Way stars. At the Pandora Cluster's estimated distance this cosmic box spans about 6 million light-years. But don't panic. You can explore the tantalizing region in a 2 minute video tour.
How to Identify that Light in the Sky (2024-06-09)
What is that light in the sky? The answer to one of humanity's more common questions may emerge from a few quick observations.  For example -- is it moving or blinking? If so, and if you live near a city, the answer is typically an airplane, since planes are so numerous and so few stars and satellites are bright enough to be seen over the glare of artificial city lights. If not, and if you live far from a city, that bright light is likely a planet such as Venus or Mars -- the former of which is constrained to appear near the horizon just before dawn or after dusk.  Sometimes the low apparent motion of a distant airplane near the horizon makes it hard to tell from a bright planet, but even this can usually be discerned by the plane's motion over a few minutes. Still unsure?   The featured chart gives a sometimes-humorous but mostly-accurate assessment.  Dedicated sky enthusiasts will likely note -- and are encouraged to provide -- polite corrections.   Chart translations: Italian, German, Latvian, Persian, Polish, Slovenian, Spanish, and Turkish
Sh2-132: The Lion Nebula (2024-06-10)
Is the Lion Nebula the real ruler of the constellation Cepheus?  This powerful feline appearing nebula is powered by two massive stars, each with a mass over 20 times greater than our Sun.  Formed from shells of ionized gas that have expanded, the nebula's energetic matter not only glows, but is dense enough to contract gravitationally and form stars.  The angular size of the Lion Nebula, officially named Sh2-132,  is slightly greater than that of the full moon.  The gaseous iconic region resides about 10,000 light years away in a constellation named after the King of Aethopia in Greek mythology.   Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)
Colorful Stars and Clouds near Rho Ophiuchi (2024-06-11)
Why is the sky near Antares and Rho Ophiuchi so colorful, yet dusty?  The colors result from a mixture of objects and processes.  Fine dust -- illuminated by starlight -- produces blue reflection nebulae. Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae. Backlit dust clouds block starlight and so appear dark.   Antares, a red supergiant and one of the brighter stars in the night sky, lights up the yellow-red clouds on the upper right of the featured image. The Rho Ophiuchi star system lies at the center of the blue reflection nebula on the left, while a different reflection nebula, IC 4605, lies just below and right of the image center.  These star clouds are even more colorful than humans can see, emitting light across the electromagnetic spectrum.   Open Science: Browse 3,400+ codes in the Astrophysics Source Code Library
Aurora over Karkonosze Mountains (2024-06-12)
It was the first time ever. At least, the first time this photographer had ever seen aurora from his home mountains.  And what a spectacular aurora it was. The Karkonosze Mountains in Poland are usually too far south to see any auroras.  But on the amazing night of May 10 - 11, purple and green colors lit up much of the night sky, a surprising spectacle that  also appeared over many mid-latitude locations around the Earth.  The featured image is a composite of six vertical exposures taken during the auroral peak. The futuristic buildings on the right are part of a meteorological observatory located on the highest peak of the Karkonosze Mountains.  The purple color is primarily due to Sun-triggered, high-energy electrons impacting nitrogen molecules in Earth's atmosphere.  Our Sun is reaching its maximum surface activity over the next two years, and although many more auroras are predicted, most will occur over regions closer to the Earth's poles.
Messier 66 Close Up (2024-06-13)
Big, beautiful spiral galaxy Messier 66 lies a mere 35 million light-years away. The gorgeous island universe is about 100 thousand light-years across, similar in size to the Milky Way. This Hubble Space Telescope close-up view spans a region about 30,000 light-years wide around the galactic core. It shows the galaxy's disk dramatically inclined to our line-of-sight. Surrounding its bright core, the likely home of a supermassive black hole, obscuring dust lanes and young, blue star clusters sweep along spiral arms dotted with the tell-tale glow of pinkish star forming regions. Messier 66, also known as NGC 3627, is the brightest of the three galaxies in the gravitationally interacting Leo Triplet.
RCW 85 (2024-06-14)
From the 1960 astronomical catalog of Rodgers, Campbell and Whiteoak, emission region RCW 85 shines in southern night skies between bright stars Alpha and Beta Centauri. About 5,000 light years distant, the hazy interstellar cloud of glowing hydrogen gas and dust is faint. But detailed structures along well-defined rims within RCW 85 are traced in this cosmic skyscape composed of 28 hours of narrow and broadband exposures. Suggestive of dramatic shapes in other stellar nurseries where natal clouds of gas and dust are sculpted by energetic winds and radiation from newborn stars, the tantalizing nebula has been called the Devil's Tower. This telescopic frame would span around 100 light-years at the estimated distance of RCW 85.
Prominences and Filaments on the Active Sun (2024-06-15)
This colorized and digitally sharpened image of the Sun is composed of frames recording emission from hydrogen atoms in the solar chromosphere on May 15. Approaching the maximum of solar cycle 25, a multitude of planet-dwarfing active regions and twisting, snake-like solar filaments are seen to sprawl across the surface of the active Sun.  Suspended in the active regions' strong magnetic fields, the filaments of plasma lofted beyond the Sun's edge appear as bright solar prominences. The large prominences seen near 4 o'clock, and just before 9 o'clock around the solar limb are post flare loops from two powerful X-class solar flares that both occurred on that day. In fact, the 4 o'clock prominence is associated with the monster active region AR 3664 just rotating off the Sun's edge.
Ou4: The Giant Squid Nebula (2024-06-17)
Squids on Earth aren't this big.  This mysterious squid-like cosmic cloud spans nearly three full moons on planet Earth's sky. Discovered in 2011 by French astro-imager Nicolas Outters, the Squid Nebula's bipolar shape is distinguished here by the telltale blue emission from doubly ionized oxygen atoms. Though apparently surrounded by the reddish hydrogen emission region Sh2-129, the true distance and nature of the Squid Nebula have been difficult to determine. Still, one investigation suggests Ou4 really does lie within Sh2-129 some 2,300 light-years away. Consistent with that scenario, the cosmic squid would represent a spectacular outflow of material driven by a triple system of hot, massive stars, cataloged as HR8119, seen near the center of the nebula. If so, this truly giant squid nebula would physically be over 50 light-years across.
Gigantic Jets over Himalayan Mountains (2024-06-18)
Yes, but can your thunderstorm do this? Pictured here are gigantic jets shooting up from a thunderstorm last week toward the Himalayan Mountains in China and Bhutan. The composite image captured four long jets that occurred only minutes apart. Gigantic jets, documented only in this century, are a type of lightning discharge that occurs between some thunderstorms and the Earth's ionosphere high above them.  They are an unusual type of lightning that is much different from regular cloud-to-cloud and cloud-to-ground lightning. The bottoms of gigantic jets appear similar to a  cloud-to-above strike called blue jets, while the tops appear similar to upper-atmosphere red sprites. Although the mechanism and trigger that cause gigantic jets remains a topic of research, it is clear that the jets reduce charge imbalance between different parts of Earth's atmosphere.  A good way to look for gigantic jets is to watch a powerful but distant thunderstorm from a clear location.
NGC 6188: Dragons of Ara (2024-06-19)
Do dragons fight on the altar of the sky?  Although it might appear that way, these dragons are illusions made of thin gas and dust. The emission nebula NGC 6188, home to the glowing clouds, is found about 4,000 light years away near the edge of a large molecular cloud, unseen at visible wavelengths, in the southern constellation Ara (the Altar). Massive, young stars of the embedded Ara OB1 association were formed in that region only a few million years ago, sculpting the dark shapes and powering the nebular glow with stellar winds and intense ultraviolet radiation. The recent star formation itself was likely triggered by winds and supernova explosions from previous generations of massive stars, that swept up and compressed the molecular gas. This impressively detailed image spans over 2 degrees (four full Moons), corresponding to over 150 light years at the estimated distance of NGC 6188.
Sandy and the Moon Halo (2024-06-20)
Last April's Full Moon shines through high clouds near the horizon, casting shadows in this garden-at-night skyscape. Along with canine sentinel Sandy watching the garden gate, the wide-angle snapshot also captured the bright Moon's 22 degree ice halo. But June's bright Full Moon will cast shadows too. This month, the Moon's exact full phase occurs at 01:08 UTC June 22. That's a mere 28 hours or so after today's June solstice (at 20:51 UTC June 20), the moment when the Sun reaches its maximum northern declination. Known to some as a Strawberry Moon, June's Full Moon is at its southernmost declination, and of course will create its own 22 degree halos in hazy night skies.
Hubble's NGC 1546 (2024-06-21)
Returning to science operations on June 14, the Hubble Space Telescope used its new pointing mode to capture this sharp image of spiral galaxy NGC 1546. A member of the Dorado galaxy group, the island universe lies a mere 50 million light-years away. The galactic disk of NGC 1546 is tilted to our line-of-sight, with the yellowish light of the old stars and bluish regions of newly formed stars shining through the galaxy's dust lanes. More distant background galaxies are scattered throughout this Hubble view. Launched in 1990, Hubble has been exploring the cosmos for more than three decades, recently celebrating its 34th anniversary.
Lynds Dark Nebula 1251 (2024-06-22)
Stars are forming in Lynds Dark Nebula (LDN) 1251. About 1,000 light-years away and drifting above the plane of our Milky Way galaxy, LDN 1251 is also less appetizingly known as "The Rotten Fish Nebula." The dusty molecular cloud is part of a complex of dark nebulae mapped toward the Cepheus flare region. Across the spectrum, astronomical explorations of the obscuring interstellar clouds reveal energetic shocks and outflows associated with newborn stars, including the telltale reddish glow from scattered Herbig-Haro objects hiding in the image. Distant background galaxies also lurk in the scene, almost buried behind the dusty expanse. This alluring view spans over four full moons on the sky, or 35 light-years at the estimated distance of LDN 1251.
The Colors of Saturn from Cassini (2024-06-23)
What creates Saturn's colors?  The featured picture of Saturn only slightly exaggerates what a human would see if hovering close to the giant ringed world.   The image was taken in 2005 by the robot Cassini spacecraft that orbited Saturn from 2004 to 2017.  Here Saturn's majestic rings appear directly only as a curved line, appearing brown, in part from its infrared glow.  The rings best show their complex structure in the dark shadows they create across the upper part of the planet.   The northern hemisphere of Saturn can appear partly blue for the same reason that Earth's skies can appear blue -- molecules in the cloudless portions of both planet's atmospheres are better at scattering blue light than red.  When looking deep into Saturn's clouds, however, the natural gold hue of Saturn's clouds becomes dominant.   It is not known why southern Saturn does not show the same blue hue -- one hypothesis holds that clouds are higher there.   It is also not known why some of Saturn's clouds are colored gold.