juliensimon/nasa-apod huggingface dataset:
InSight's First Image from Mars (2018-11-27)

Welcome to Mars, NASA Insight.  Yesterday NASA's robotic spacecraft InSight made a dramatic landing on Mars after a six-month trek across the inner Solar System. Needing to brake from 20,000 km per hour to zero in about seven minutes, Insight decelerated by as much as 8  g's and heated up to 1500 degrees Celsius as it deployed a heat shield, a parachute, and at the end, rockets.  The featured image was the first taken by InSight on Mars, and welcome proof that the spacecraft had shed enough speed to land softly and function on the red planet. During its final descent, InSight's rockets kicked up dust which can be seen stuck to the lens cap of the Instrument Context Camera. Past the spotty dirt, parts of the lander that are visible include cover bolts at the bottom and a lander footpad on the lower right. Small rocks are visible across the rusty red soil, while the arc across the top of the image is the Martian horizon dividing land and sky. Over the next few weeks InSight will deploy several scientific instruments, including a rumble-detecting seismometer.  These instruments are expected to give humanity unprecedented data involving the interior of Mars, a region thought to harbor formation clues not only about Mars, but Earth.
IC 1871: Inside the Soul Nebula (2018-11-28)

This cosmic close-up looks deep inside the Soul Nebula. The dark and brooding dust clouds on the left, outlined by bright ridges of glowing gas, are cataloged as IC 1871. About 25 light-years across, the telescopic field of view spans only a small part of the much larger Heart and Soul nebulae. At an estimated distance of 6,500 light-years the star-forming complex lies within the Perseus spiral arm of our  Milky Way Galaxy, seen in planet Earth's skies toward the constellation Cassiopeia. An example of triggered star formation, the dense star-forming clouds of IC 1871 are themselves sculpted by the intense winds and radiation of the region's massive young stars. The featured image appears mostly red due to the emission of a specific color of light emitted by excited hydrogen gas.

Image credit: Mark Hanson
Across Corona Australis (2018-11-29)

Cosmic dust clouds are draped across a rich field of stars in this broad telescopic panorama near the northern boundary of Corona Australis, the Southern Crown. Less than 500 light-years away the denser clouds effectively block light from more distant background stars in the Milky Way. The entire vista spans about 5 degrees or nearly 45 light-years at the clouds' estimated distance. Toward the right lies a group of bluish reflection nebulae cataloged as NGC 6726, 6727, 6729 and IC 4812. The characteristic blue color is produced as light from hot stars is reflected by the cosmic dust. The dust also obscures from view stars in the region still in the process of formation. Smaller yellowish nebula NGC 6729 surrounds young variable star R Coronae Australis. Below it are arcs and loops identified as Herbig Haro (HH) objects associated with energetic newborn stars. Magnificent globular star cluster NGC 6723 is above and right of the nebulae. Though NGC 6723 appears to be part of the group, its ancient stars actually lie nearly 30,000 light-years away, far beyond the young stars of the Corona Australis dust clouds.

Image credit: Fabian Neyer
A Cold River to Orion (2018-11-30)

Ice is forming on the river Lielupe as it flows through the landscape in this winter's night scene. Even in motion the frigid water still reflects a starry sky, though. The well planned, Orion-centered panorama looks toward the south, taken in three exposures from a bridge near the village of Stalgene, Latvia, planet Earth. Drifting pancakes of ice leave streaks in the long exposures, while familiar stars of Orion and the northern winter night appear above and below the horizon. Village lights along the horizon include skyward beams from the local community church. This image was a first place winner in the 2018 StarSpace astrophotography competition.

Image credit: Juris Sennikovs
Mount Everest Star Trails (2018-12-01)

The highest peak on planet Earth is framed in this mountain and night skyscape. On September 30, the digital stack of 240 sequential exposures made with a camera fixed to a tripod at an Everest Base Camp captured the sheer north face of the Himalayan mountain and foreground illuminated by bright moonlight. Taken over 1.5 hours, the sequence also recorded colorful star trails. Reflecting the planet's daily rotation on its axis, their motion is along gentle concentric arcs centered on the south celestial pole, a point well below the rugged horizon. The color of the trails actually indicates the temperatures of the stars. Blueish hues are from hotter stars, and yellow to reddish hues are from stars cooler than the Sun.

Image credit: Jeff Dai
The Fairy of Eagle Nebula (2018-12-02)

The dust sculptures of the Eagle Nebula are evaporating.  As powerful starlight whittles away these cool cosmic mountains, the statuesque pillars that remain might be imagined as mythical beasts.  Featured here is one of several striking dust pillars of the Eagle Nebula that might be described as a gigantic alien fairy.   This fairy, however, is ten light years tall and spews radiation much hotter than common fire. The greater Eagle Nebula, M16, is actually a giant evaporating shell of gas and dust inside of which is a growing cavity filled with a spectacular stellar nursery currently forming an open cluster of stars.  This great pillar, which is about 7,000 light years away, will likely evaporate away in about 100,000 years.  The featured image in scientifically re-assigned colors was released in 2005 as part of the fifteenth anniversary celebration of the launch of the Hubble Space Telescope.   New: Instagram page features cool images recently submitted to APOD
Spiraling Supermassive Black Holes (2018-12-03)

Do black holes glow when they collide?  When merging, co-orbiting black holes are sure to emit a burst of unusual gravitational radiation, but will they emit light, well before that, if they are surrounded by gas?  To help find out, astrophysicists created a sophisticated computer simulation. The simulation and featured resulting video accurately depicts two spiraling supermassive black holes, including the effects of Einstein's general relativity on the surrounding gas and light. The video first shows the system from the top, and later from the side where unusual gravitational lens distortions are more prominent.  Numerical results indicate that gravitational and magnetic forces should energize the gas to emit high-energy light from the ultraviolet to the X-ray.  The emission of such light may enable humanity to detect and study supermassive black hole pairs well before they spiral together.   News: Four new gravitational-wave emitting black hole mergers discovered.  Open Science: Browse 1,800+ codes in the Astrophysics Source Code Library
Rocket Launch between Mountains (2018-12-04)

What's happening between those mountains? A rocket is being launched to space. Specifically, a Long March 3B Carrier Rocket was launched from Xichang Satellite Launch Center in Sichuan Province in China about two week ago.  The rocket lifted two navigation satellites to about 2,000 kilometers above the Earth's surface, well above the orbit of the International Space Station, but well below the orbit of geostationary satellites.  China's Chang'e 3 mission that landed the robotic Yutu rover on the Moon was launched from Xichang in 2013.  The featured image was taken about 10 kilometers from the launch site and is actually a composite of nine exposures, including a separate background image.

Image credit: Yudong Jiang
Highlights of the North Winter Sky (2018-12-05)

What can you see in the night sky this season?  The featured graphic gives a few highlights for Earth's northern hemisphere. Viewed as a clock face centered at the bottom, early (northern) 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.  As happens during any season, constellations appear the same year to year, and, as usual, the Geminids meteor shower will peak in mid-December.  Also as usual, the International Space Station (ISS) can be seen, at times, as a bright spot drifting across the sky after sunset.  Less usual, the Moon is expected to pass nearly in front of several planets in early January.  A treat this winter is Comet 46P/Wirtanen, already bright, will pass only 36 lunar distances from the Earth in mid-December, potentially making it easily visible to the unaided eye.

Image credit: Universe2go.com
Cetus Galaxies and Supernova (2018-12-06)

Large spiral galaxy NGC 1055 at top left joins spiral Messier 77 (bottom right) in this cosmic view toward the aquatic constellation Cetus. The narrowed, dusty appearance of edge-on spiral NGC 1055 contrasts nicely with the face-on view of M77's bright nucleus and spiral arms. Both over 100,000 light-years across, the pair are dominant members of a small galaxy group about 60 million light-years away. At that estimated distance, M77 is one of the most remote objects in Charles Messier's catalog, and is separated from fellow island universe NGC 1055 by at least 500,000 light-years. The field of view is about the size of the full Moon on the sky and includes colorful foreground Milky Way stars along with more distant background galaxies. Taken on November 28, the sharp image also includes newly discovered supernova SN2018ivc, its location indicated in the arms of M77. The light from the explosion of one of M77's massive stars was discovered by telescopes on planet Earth only a few days earlier on November 24.

Image credit: Massimiliano Veschini
December's Comet Wirtanen (2018-12-07)

Coming close in mid-December, Comet 46P Wirtanen hangs in this starry sky over the bell tower of a Romanesque church. In the constructed vertical panorama, a series of digital exposures capture its greenish coma on December 3 from Sant Llorenc de la Muga, Girona, Catalonia, Spain, planet Earth. With an orbital period that is now about 5.4 years, the periodic comet's perihelion, its closest approach, to the Sun will be on December 12. On December 16 it will be closest to Earth, passing at a distance of about 11.6 million kilometers or 39 light-seconds. That's close for a comet, a mere 30 times the Earth-Moon distance. A good binocular target for comet watchers, Wirtanen could be visible to the unaided eye from a dark sky site. To spot it after dusk on December 16, look close on the sky to the Pleiades star cluster in Taurus.

Image credit: Juan Carlos Casado
Tiny Planet Timelapse (2018-12-08)

You can pack a lot of sky watching into 30 seconds on this tiny planet. Of course, the full spherical image timelapse video was recorded on planet Earth, from Grande Pines Observatory outside Pinehurst, North Carolina. It was shot in early September with a single camera and circular fisheye lens, digitally combining one 24-hour period with camera and lens pointed up with one taken with camera and lens pointed down. The resulting image data is processed and projected onto a flat frame centered on the nadir, the point directly below the camera. Watch as clouds pass, shadows creep, and the sky cycles from day to night when stars swirl around the horizon. Keep watching, though. In a second sequence the projected center is the south celestial pole, planet Earth's axis of rotation below the tiny planet horizon. Holding the stars fixed, the horizon itself rotates as the tiny planet swings around the frame, hiding half the sky through day and night.

Image credit: Brian Haidet
Aurora Shimmer, Meteor Flash (2018-12-09)

Some night skies are serene and passive -- others shimmer and flash.  The later, in the form of auroras and meteors, haunted skies over the island of Kvaløya, near Tromsø Norway on 2009 December 13. This 30 second long exposure records a shimmering auroral glow gently lighting the wintery coastal scene. A study in contrasts, the image also captures the sudden flash of a fireball meteor from the excellent Geminid meteor shower of 2009. Streaking past familiar stars in the handle of the Big Dipper, the trail points back toward the constellation Gemini, off the top of the view. Both auroras and meteors occur in Earth's upper atmosphere at altitudes of 100 kilometers or so, but aurora caused by energetic charged particles from the magnetosphere, while meteors are trails of cosmic dust. Nine years after this photograph was taken, toward the end of this week, the yearly 2018 Geminids meteor shower will peak again, although this time their flashes will compete with the din of a half-lit first-quarter moon during the first half of the night.   Free Download: 2019 APOD Calendar

Image credit: Bjørnar G. Hansen
Sound and Light Captured by Mars InSight (2018-12-10)

Your arm on Mars has unusual powers.  For one thing it is nearly 2 meters long, has a scoop and grapple built into its hand, and has a camera built into its forearm.  For another, it will soon deploy your ear -- a sensitive seismometer that will listen for distant rumblings -- onto the surface of Mars.  Your SEISmomet-ear is the orange box in the foreground, while the gray dome behind it will be its protective cover.  Your arm is attached to the InSight robotic lander that touched down on Mars two weeks ago. Somewhat unexpectedly, your ear has already heard something -- slight vibrations caused by the Martian wind flowing over the solar panels.  Light from the Sun is being collected by the solar panels, part of one being visible on the far right. Actually, at the present time, you have two arms operating on Mars, but they are separated by about 600 kilometers. That's because your other active arm is connected to the Curiosity rover exploring a distant crater.  Taken a week ago, rusty soil and rocks are visible in the featured image beyond Insight, as well as the orange sky of Mars.   Follow APOD on: Instagram, Facebook,  Reddit, or Twitter
Arp 188 and the Tadpole's Tail (2018-12-11)

Why does this galaxy have such a long tail?   In this stunning vista, based on image data from the Hubble Legacy Archive, distant galaxies form a dramatic backdrop for disrupted spiral galaxy Arp 188, the Tadpole Galaxy. The cosmic tadpole is a mere 420 million light-years distant toward the northern constellation of the Dragon (Draco). Its eye-catching tail is about 280 thousand light-years long and features massive, bright blue star clusters. One story goes that a more compact intruder galaxy crossed in front of Arp 188 - from right to left in this view - and was slung around behind the Tadpole by their gravitational attraction. During the close encounter, tidal forces drew out the spiral galaxy's stars, gas, and dust forming the spectacular tail. The intruder galaxy itself, estimated to lie about 300 thousand light-years behind the Tadpole, can be seen through foreground spiral arms at the upper right. Following its terrestrial namesake, the Tadpole Galaxy will likely lose its tail as it grows older, the tail's star clusters forming smaller satellites of the large spiral galaxy.   New: Instagram page features cool images recently submitted to APOD
M43: Orion Falls (2018-12-12)

Is there a waterfall in Orion? No, but some of the dust in M43 appears similar to a waterfall on Earth.  M43, part of the Orion Molecular Cloud Complex, is the often imaged but rarely mentioned neighbor of the more famous M42. M42, which includes many bright stars from the Trapezium cluster, lies above the featured scene. M43 is itself a star forming region and although laced with filaments of dark dust, is composed mostly of glowing hydrogen. The entire Orion field, located about 1600 light years away, is inundated with many intricate and picturesque filaments of dust.  Opaque to visible light, dark dust is created in the outer atmosphere of massive cool stars and expelled by a strong outer wind of protons and electrons.   Free Download: 2019 APOD Calendar (v4 with light background)

Image credit: Zhuoqun Wu,
Chilescope Telescope 2
3D Bennu (2018-12-13)

Put on your red/blue glasses and float next to asteroid 101955 Bennu. Shaped like a spinning top toy with boulders littering its rough surface, the tiny Solar System world is about 1 Empire State Building (less than 500 meters) across. Frames used to construct this 3D anaglyph were taken by PolyCam on board the OSIRIS_REx spacecraft on December 3 from a distance of about 80 kilometers. Now settling in to explore Bennu from orbit, the OSIRIS-REx mission is expected to deliver samples of the asteroid to planet Earth in 2023. Samples of dust from another asteroid will streak through Earth's atmosphere much sooner though, when the Geminid meteor shower peaks in predawn skies on December 14. The parent body for the annual Geminids is asteroid 3200 Phaethon.  Watch: Geminid Meteor Shower
Swimming on Jupiter (2018-12-14)

On October 29, the Juno spacecraft once again dove near the turbulent Jovian cloud tops. Its 16th orbital closest approach or perijove passage, brought Juno within 3,500 kilometers of the Solar System's largest planetary atmosphere. These frames, recorded by JunoCam while the spacecraft cruised 20 - 50 thousand kilometers above the planet's middle southern latitudes, seem to follow a swirling cloud shaped remarkably like a dolphin. Swimming along Jupiter's darker South South Temperate Belt, this dolphin is itself planet-sized though, some thousands of kilometers across. Juno's next perijove passage is coming up on December 21.
Geminids and Friends (2018-12-15)

From a radiant in the constellation of the Twins, the annual Geminid meteor shower rained down on our fair planet this week. This beautiful skyscape collects about 70 of Gemini's lovely shooting stars in a digital composition made from multiple exposures. The exposures were taken over a six hour period near the shower's peak. The camera was tracking the dark predawn sky on December 14 from Teide National Park on the Canary Island Tenerife. Though Gemini lies off the top left of the frame, the Milky Way sweeps through the starry background. Sharing the sky below and left of center are recognizable stars and nebulosities of Orion. A yellowish Aldebaran and the Hyades are toward the right along with the Pleiades star cluster. Also a welcome visitor to this night sky, the faint green coma of Comet 46P Wirtanen, closest to Earth this weekend, lies below the Pleiades stars. Dust swept up from the orbit of active asteroid 3200 Phaethon, Gemini's meteors enter Earth's atmosphere traveling at about 35 kilometers per second.

Image credit: El Cielo de Canarias
Comet Wirtanen Passes by the Earth (2018-12-16)

Today Comet Wirtanen passes by the Earth. The kilometer-sized dirty snowball orbits the Sun every 5.4 years, ranging as far out as Jupiter and as close in as the Earth. Today Comet 46P/Wirtanen passes within only 31 lunar distances to the Earth, the closest approach in 70 years.  If you know where to look (Taurus), you can see the comet through binoculars as an unusual blue smudge.  Pictured a week ago, Comet Wirtanen was photographed in the sky beyond an old abandoned church in Skagen, Denmark.  The image composite also captures the astrophotographer.  After today, the comet will begin to fade as it recedes from the Earth and the Sun.   Free Download: 2019 APOD Calendar (v5)

Image credit: Ruslan Merzlyakov  
(RMS Photography)
M31: The Andromeda Galaxy (2018-12-17)

What is the nearest major galaxy to our own Milky Way Galaxy?  Andromeda.  In fact, our Galaxy is thought to look much like Andromeda. Together these two galaxies dominate the Local Group of galaxies. The diffuse light from Andromeda is caused by the hundreds of billions of stars that compose it. The several distinct stars that surround Andromeda's image are actually stars in our Galaxy that are well in front of the background object. Andromeda is frequently referred to as M31 since it is the 31st object on Messier's list of diffuse sky objects. M31 is so distant it takes about two million years for light to reach us from there. Although visible without aid, the featured image of M31 is a digital mosaic of 20 frames taken with a small telescope. Much about M31 remains unknown, including exactly how long it will be before it  collides with our home galaxy.   Jump around the Universe: Random APOD Generator

Image credit: Robert Gendler
Methane Bubbles Frozen in Lake Baikal (2018-12-18)

What are these bubbles frozen into Lake Baikal? Methane.  Lake Baikal, a UNESCO World Heritage Site in Russia, is the world's largest (by volume), oldest, and deepest lake, containing over 20% of the world's fresh water. The lake is also a vast storehouse of methane, a greenhouse gas that, if released, could potentially increase the amount of infrared light absorbed by Earth's atmosphere, and so increase the average temperature of the entire planet. Fortunately, the amount of methane currently bubbling out is not climatologically important. It is not clear what would happen, though, were temperatures to significantly increase in the region, or if the water level in Lake Baikal were to drop.  Pictured, bubbles of rising methane froze during winter into the exceptionally clear ice covering the lake.

Image credit: Kristina Makeeva
A Rainbow Geminid Meteor (2018-12-19)

Meteors can be colorful. While the human eye usually cannot discern many colors, cameras often can. Pictured is a Geminid captured by camera during last week's meteor shower that was not only impressively bright, but colorful. The radiant grit cast off by asteroid 3200 Phaethon blazed a path across Earth's atmosphere longer than 60 times the angular diameter of the Moon. Colors in meteors usually originate from ionized elements released as the meteor disintegrates, with blue-green typically originating from magnesium, calcium radiating violet, and nickel glowing green. Red, however, typically originates from energized nitrogen and oxygen in the Earth's atmosphere.  This bright meteoric fireball was gone in a flash -- less than a second -- but it left a wind-blown ionization trail that remained visible for several minutes, the start of which can be seen here.   Gallery: Geminid Meteors 2018

Image credit: Dean Rowe
Red Nebula, Green Comet, Blue Stars (2018-12-20)

This festively colored skyscape was captured in the early morning hours of December 17, following Comet Wirtanen's closest approach to planet Earth. The comet was just visible to the eye. The lovely green color of its fluorescing cometary atmosphere or coma is brought out here only by adding digital exposures registered on the comet's position below the Pleiades star cluster. The exposures also bring out blue starlight reflected by the dust clouds surrounding the young Pleiades stars. Gaze (toward the left) across dusty dark nebulae along the edge of the Perseus molecular cloud and you'll travel to emission nebula NGC 1499, also known as the California nebula. Too faint for the eye, the cosmic cloud's pronounced reddish glow is from electrons recombining with ionized hydrogen atoms. Around December 23rd, Comet Wirtanen should be easy to find with binoculars when it sweeps close to bright star Capella in the northern winter constellation Auriga, the Charioteer.

Image credit: Tom Masterson