juliensimon/nasa-apod huggingface dataset:
NGC 602 and Beyond (2020-01-11)

Near the outskirts of the Small Magellanic Cloud, a satellite galaxy some 200 thousand light-years distant, lies 5 million year young star cluster NGC 602. Surrounded by natal gas and dust, NGC 602 is featured in this stunning Hubble image of the region, augmented by images in the X-ray by Chandra,  and in the infrared by Spitzer. Fantastic ridges and swept back shapes strongly suggest that energetic radiation and shock waves from NGC 602's massive young stars have eroded the dusty material and triggered a progression of star formation moving away from the cluster's center. At the estimated distance of the Small Magellanic Cloud, the Picture spans about 200 light-years, but a tantalizing assortment of background galaxies are also visible in this sharp multi-colored view. The background galaxies are hundreds of millions of light-years or more beyond NGC 602.
Stars and Dust in Corona Australis (2020-01-12)

Cosmic dust clouds and young, energetic stars inhabit this telescopic vista, less than 500 light-years away toward the northern boundary of Corona Australis, the Southern Crown. The dust clouds effectively block light from more distant background stars in the Milky Way. But the striking complex of reflection nebulae cataloged as NGC 6726, 6727, and IC 4812 produce a characteristic blue color as light from the region's young hot stars is reflected by the cosmic dust. The dust also obscures from view stars still in the process of formation. At the left, smaller yellowish nebula NGC 6729 bends around young variable star R Coronae Australis. Just below it, glowing arcs and loops shocked by outflows from embedded newborn stars are identified as Herbig-Haro objects. On the sky this field of view spans about 1 degree. That corresponds to almost 9 light-years at the estimated distance of the nearby star forming region.    Video: Best of APOD 2019 for the Night Sky Network

Image credit: CHART32 Team
A Desert Eclipse (2020-01-13)

A good place to see a ring-of-fire eclipse, it seemed, would be from a desert. In a desert, there should be relatively few obscuring clouds and trees.  Therefore late last December a group of photographers traveled to the United Arab Emirates and Rub al-Khali, the largest continuous sand desert in world, to capture clear images of an unusual eclipse that would be passing over.  A ring-of-fire eclipse is an annular eclipse that occurs when the Moon is far enough away on its elliptical orbit around the Earth so that it appears too small, angularly, to cover the entire Sun. At the maximum of an annular eclipse, the edges of the Sun can be seen all around the edges of the Moon, so that the Moon appears to be a dark spot that covers most -- but not all -- of the Sun. This particular eclipse, they knew, would peak soon after sunrise.  After seeking out such a dry and barren place, it turned out that some of the most interesting eclipse images actually included a tree in the foreground, because, in addition to the sand dunes, the tree gave the surreal background a contrasting sense of normalcy, scale, and texture.    Explore the Universe: Random APOD Generator

Image credit: Maxime Daviron
Evidence of an Active Volcano on Venus (2020-01-14)

Are volcanoes still active on Venus?  More volcanoes are known on Venus than Earth, but when Venusian volcanoes last erupted is not directly known. Evidence bolstering very recent volcanism on Venus has recently been uncovered, though, right here on Earth. Lab results showed that images of surface lava would become dim in the infrared in only months in the dense Venusian atmosphere, a dimming not seen in ESA's Venus Express images. Venus Express entered orbit around Venus in 2006 and remained in contact with Earth until 2014. Therefore, the infrared glow (shown in false-color red) recorded by Venus Express for Idunn Mons and featured here on a NASA Magellan image indicates that this volcano erupted very recently -- and is still active today.  Understanding the volcanics of Venus might lead to insight about the volcanics on Earth, as well as elsewhere in our Solar System.    New: APOD now available in Turkish from Turkey
Iridescent Clouds over Sweden (2020-01-15)

Why would these clouds multi-colored?  A relatively rare phenomenon in clouds known as iridescence can bring up unusual colors vividly or even a whole spectrum of colors simultaneously. These polar stratospheric clouds clouds, also known as nacreous and mother-of-pearl clouds,  are formed of small water droplets of nearly uniform size. When the Sun is in the right position and, typically, hidden from direct view, these thin clouds can be seen significantly diffracting sunlight in a nearly coherent manner, with different colors being deflected by different amounts. Therefore, different colors will come to the observer from slightly different directions. Many clouds start with uniform regions that could show iridescence but quickly become too thick, too mixed, or too angularly far from the Sun to exhibit striking colors. The featured image and an accompanying video were taken late last year over Ostersund, Sweden.   Follow APOD in English on: Instagram, Facebook,  Reddit, or Twitter

Image credit: Goran Strand
NGC 247 and Friends (2020-01-16)

About 70,000 light-years across, NGC 247 is a spiral galaxy smaller than our Milky Way. Measured to be only 11 million light-years distant it is nearby though. Tilted nearly edge-on as seen from our perspective, it dominates this telescopic field of view toward the southern constellation Cetus. The pronounced void on one side of the galaxy's disk recalls for some its popular name, the Needle's Eye galaxy. Many background galaxies are visible in this sharp galaxy portrait, including the remarkable string of four galaxies just below and left of NGC 247 known as Burbidge's Chain. Burbidge's Chain galaxies are about 300 million light-years distant. NGC 247 itself is part of the Sculptor Group of galaxies along with the shiny spiral NGC 253.

Image credit: Eric Benson
Apollo 17: A Stereo View from Lunar Orbit (2020-01-17)

Get out your red/blue glasses and check out this awesome stereo view of another world. The scene was recorded by Apollo 17 mission commander Eugene Cernan on December 11, 1972, one orbit before descending to land on the Moon. The stereo anaglyph was assembled from two photographs (AS17-147-22465, AS17-147-22466) captured from his vantage point on board the Lunar Module Challenger as he and Dr. Harrison Schmitt flew over Apollo 17's landing site in the Taurus-Littrow Valley. The broad, sunlit face of the mountain dubbed South Massif rises near the center of the frame, above the dark floor of Taurus-Littrow to its left. Beyond the mountains, toward the lunar limb, lies the Moon's Mare Serenitatis. Piloted by Ron Evans, the Command Module America is visible in orbit in the foreground against the South Massif's peak.
An Almost Eclipse of the Moon (2020-01-18)

This composited series of images follows the Moon on January 10, the first Full Moon of 2020, in Hungarian skies. The lunar disk is in mid-eclipse at the center of the sequence though. It looks only slightly darker there as it passes through the light outer shadow or penumbra of planet Earth. In fact during this penumbral lunar eclipse the Moon almost crossed into the northern edge of Earth's dark central shadow or umbra. Subtle and hard to see, this penumbral lunar eclipse was the first of four lunar eclipses in 2020, all of which will be penumbral lunar eclipses.

Image credit: Gyorgy Soponyai
M1: The Incredible Expanding Crab Nebula (2020-01-19)

Are your eyes good enough to see the Crab Nebula expand?  The Crab Nebula is cataloged as M1, the first on Charles Messier's famous list of things which are not comets. In fact, the Crab is now known to be a supernova remnant, an expanding cloud of debris from the explosion of a massive star. The violent birth of the Crab was witnessed by astronomers in the year 1054. Roughly 10 light-years across today, the nebula is still expanding at a rate of over 1,000 kilometers per second. Over the past decade, its expansion has been documented in this stunning time-lapse movie. In each year from 2008 to 2017, an image was produced with the same telescope and camera from a remote observatory in Austria. Combined in the time-lapse movie, the 10 images represent 32 hours of total integration time. The sharp, processed frames even reveal the dynamic energetic emission within the incredible expanding Crab. The Crab Nebula lies about 6,500 light-years away in the constellation Taurus.   Teachers: APOD in the Classroom

Image credit: Detlef Hartmann
Quadrantid Meteors through Orion (2020-01-20)

Why are these meteor trails nearly parallel? Because they were all shed by the same space rock and so can be traced back to the same direction on the sky: the radiant of the Quadrantid Meteor Shower.  This direction used to be toward the old constellation of Quadrans Muralis, hence the name Quadrantids, but when the International Astronomical Union formulated its list of modern constellations in 1922, this constellation did not make the list. Even though the meteors are now considered to originate from the recognized constellation of Bootes, the old name stuck. Regardless of the designation, every January the Earth moves through a dust stream and bits of this dust glow as meteors as they heat up in Earth's atmosphere.  The featured image composite was taken on January 4 with a picturesque snowy Slovakian landscape in the foreground, and a deep-exposure sky prominently featuring the constellation Orion in the background. The red star Betelgeuse appears unusually dim -- its fading over the past few months is being tracked by astronomers.   Teachers: APOD in the Classroom

Image credit: Petr
Horálek
Parker: Sounds of the Solar Wind (2020-01-21)

What does the solar wind sound like? A wind of fast moving particles blows out from our Sun, and although space transmits sound poorly, particle impact and variable-field data from NASA's near-Sun Parker Solar Probe is being translated into  sound. The disarming audio track of the featured video recounts several of these reverberations, including spooky-sounding Langmuir Waves (heard first), hurricane-sounding Whistler Mode Waves (heard next), and hard-to-describe Dispersive Chirping Waves (heard last). Also impressive is the video's time-lapse visual track which shows Parker's view to the side of its sun shield, and where the planets Earth, Jupiter, Mercury and Venus appear in succession, interspersed with bursts of powerful cosmic rays impacting the imager.  The nature of the solar wind near Mercury is surprisingly different from near the Earth, and much study is underway to better understand the differences.   Discovery + Outreach: Graduate student research position open for APOD
The Hyades Star Cluster (2020-01-22)

It is the closest cluster of stars to the Sun. The Hyades open cluster is bright enough to have been remarked on even thousands of years ago, yet is not as bright or compact as the nearby Pleiades (M45) star cluster. Pictured here is a particularly deep image of the Hyades which has brings out vivid star colors and faint coincidental nebulas.  The brightest star in the field is yellow Aldebaran, the eye of the bull toward the constellation of Taurus. Aldebaran, at 65 light-years away, is now known to be unrelated to the Hyades cluster, which lies about 150 light-years away.  The central Hyades stars are spread out over about 15 light-years. Formed about 625 million years ago, the Hyades likely shares a common origin with the Beehive cluster (M44), a naked-eye open star cluster toward the constellation of Cancer, based on M44's motion through space and remarkably similar age.

Image credit: Jose Mtanous
Globular Star Cluster NGC 6752 (2020-01-23)

Some 13,000 light-years away toward the southern constellation Pavo, the globular star cluster NGC 6752 roams the halo of our Milky Way galaxy. Over 10 billion years old, NGC 6752 follows clusters Omega Centauri and 47 Tucanae as the third brightest globular in planet Earth's night sky. It holds over 100 thousand stars in a sphere about 100 light-years in diameter. Telescopic explorations of the NGC 6752 have found that a remarkable fraction of the stars near the cluster's core, are multiple star systems. They also reveal the presence of blue straggle stars, stars which appear to be too young and massive to exist in a cluster whose stars are all expected to be at least twice as old as the Sun. The blue stragglers are thought to be formed by star mergers and collisions in the dense stellar environment at the cluster's core. This sharp color composite also features the cluster's ancient red giant stars in yellowish hues. (Note: The bright, spiky blue star at 11 o'clock from the cluster center is a foreground star along the line-of-sight to NGC 6752)

Image credit: Jose Joaquin Perez
Into the  Shadow (2020-01-24)

On January 21, 2019 moonwatchers on planet Earth saw a total lunar eclipse. In 35 frames this composite image follows the Moon that night as it crossed into Earth's dark umbral shadow. Taken 3 minutes apart, they almost melt together in a continuous screen that captures the dark colors within the shadow itself and the northern curve of the shadow's edge. Sunlight scattered by the atmosphere into the shadow causes the lunar surface to appear reddened during totality (left), but close to the umbra's edge, the limb of the eclipsed Moon shows a remarkable blue hue. The blue eclipsed moonlight originates as rays of sunlight pass through layers high in Earth's upper stratosphere, colored by ozone that scatters red light and transmits blue.  The Moon's next crossing into Earth's umbral shadow, will be on May 26, 2021.

Image credit: Laszlo Francsics
Rubin's Galaxy (2020-01-25)

In this Hubble Space Telescope image the bright, spiky stars lie in the foreground toward the heroic northern constellation Perseus and well within our own Milky Way galaxy. In sharp focus beyond is UGC 2885, a giant spiral galaxy about 232 million light-years distant. Some 800,000 light-years across compared to the Milky Way's diameter of 100,000 light-years or so, it has around 1 trillion stars. That's about 10 times as many stars as the Milky Way. Part of a current investigation to understand how galaxies can grow to such enormous sizes, UGC 2885 was also part of astronomer Vera Rubin's pioneering study of the rotation of spiral galaxies. Her work was the first to convincingly demonstrate the dominating presence of dark matter in our universe.
Hills, Ridges, and Tracks on Mars (2020-01-26)

Sometimes, even rovers on Mars stop to admire the scenery. Just late last November the Curiosity rover on Mars paused to photograph its impressive surroundings. One thing to admire, straight ahead, was Central Butte, an unusual flat hill studied by Curiosity just a few days before this image was taken. To its right was distant Mount Sharp, the five-kilometer central peak of entire Gale crater, the interior of which Curiosity is exploring. Mount Sharp, covered in sulfates, appears quite bright in this colorized, red-filtered image. To the far left, shrouded in a very dark shadow, was the south slope of Vera Rubin ridge, an elevation explored previously by Curiosity.  Between the ridge and butte were tracks left by Curiosity's wheels as they rolled forward, out of the scene. In the image foreground is, of course, humanity's current eyes on Mars: the complex robotic rover Curiosity itself.  Later this year, if all goes well, NASA will have another rover -- and more eyes -- on Mars. Today you can help determine the name of this rover yourself, but tomorrow is the last day to cast your vote.   Help Name the Mars 2020 Rover: Vote here!
Comet CG Evaporates (2020-01-27)

Where do comet tails come from?  There are no obvious places on the nuclei of comets from which the jets that create comet tails emanate.  One of the best images of emerging jets is shown in the featured picture, taken in 2015 by ESA's robotic Rosetta spacecraft that orbited Comet 67P/Churyumov-Gerasimenko (Comet CG) from 2014 to 2016.  The picture shows plumes of gas and dust escaping numerous places from Comet CG's nucleus as it neared the Sun and heated up.  The comet has two prominent lobes, the larger one spanning about 4 kilometers, and a smaller 2.5-kilometer lobe connected by a narrow neck. Analyses indicate that evaporation must be taking place well inside the comet's surface to create the jets of dust and ice that we see emitted through the surface.  Comet CG (also known as Comet 67P) loses in jets about a meter of radius during each of its 6.44-year orbits around the Sun, a rate at which will completely destroy the comet in only thousands of years. In 2016, Rosetta's mission ended with a controlled impact onto Comet CG's surface.   Outreach Astronomers: Future APOD writers sought.
Star Formation in the Tadpole Nebula (2020-01-28)

What's all of the commotion in the Tadpole Nebula? Star formation.  Dusty emission in the Tadpole Nebula, IC 410, lies about 12,000 light-years away in the northern constellation of the Charioteer (Auriga). The cloud of glowing gas is over 100 light-years across, sculpted by stellar winds and radiation from embedded open star cluster NGC 1893. Formed in the interstellar cloud a mere 4 million years ago, bright newly formed cluster stars are seen all around the star-forming nebula.  Notable near the image center are two relatively dense streamers of material trailing away from the nebula's central regions. Potentially sites of ongoing star formation in IC 410, these cosmic tadpole shapes are about 10 light-years long. The featured image was taken in infrared light by NASA's Wide Field Infrared Survey Explorer (WISE) satellite.   Discovery + Outreach: Graduate student research position open for APOD

Image credit: :
Francesco Antonucci
Milky Way over Yellowstone (2020-01-29)

The Milky Way was not created by an evaporating lake. The pool of vivid blue water, about 10 meters across, is known as Silex Spring and is located in Yellowstone National Park in Wyoming, USA. Steam rises off the spring, heated by a magma chamber deep underneath known as the Yellowstone hotspot.  The steam blurs the image of Jupiter, making it seem unusually large.  Unrelated and far in the distance, the central band of our Milky Way Galaxy rises high overhead, a band lit by billions of stars.  The featured picture is a 3-image panorama taken last August.  If the Yellowstone hotspot causes another supervolcanic eruption as it did 640,000 years ago, a large part of North America would be affected.

Image credit: Lori Jacobs
Two Clusters and a Comet (2020-01-30)

This lovely starfield spans some four full moons (about 2 degrees) across the heroic northern constellation of Perseus. In telescopic exposures made during the nights of January 24, 26, and 28 it holds the famous pair of open or galactic star clusters h and Chi Persei with comet PanSTARRS (C/2017 T2) captured each night as it swept left to right across the field of view. Also cataloged as NGC 869 (right) and NGC 884, both star clusters are about 7,000 light-years away and contain stars much younger and hotter than the Sun.  Separated by only a few hundred light-years, the clusters are both 13 million years young based on the ages of their individual stars, evidence that they were likely a product of the same star-forming region. Discovered in 2017 while still beyond the orbit of Saturn, Comet PanSTARRs is a new visitor to the inner solar system and just over 13 light-minutes from planet Earth. Always a rewarding sight in binoculars, the Double Cluster is even visible to the unaided eye from dark locations. C/2017 T2 could remain a telescopic comet though. One of the brightest comets anticipated in 2020 it makes its closest approach to the Sun in early May.

Image credit: CARA Project
Goldilocks Zones and Stars (2020-01-31)

The Goldilocks zone is the habitable zone around a star where it's not too hot and not too cold for liquid water to exist on the surface of orbiting planets. This intriguing infographic includes relative sizes of those zones for yellow G stars like the Sun, along with orange K dwarf stars and red M dwarf stars, both cooler and fainter than the Sun. M stars (top) have small, close-in Goldilocks zones. They are also seen to live long (100 billion years or so) and are very abundant, making up about 73 percent of the stars in the Milky Way. Still, they have very active magnetic fields and may produce too much radiation harmful to life, with an estimated X-ray irradiance 400 times the quiet Sun. Sun-like G stars (bottom) have large Goldilocks zones and are relatively calm, with low amounts of harmful radiation. But they only account for 6 percent of Milky Way stars and are much shorter lived. In the search for habitable planets, K dwarf stars could be just right, though. Not too rare they have 40 billion year lifetimes, much longer than the Sun. With a relatively wide habitable zone they produce only modest amounts of harmful radiation. These Goldilocks stars account for about 13 percent of the stars of the Milky Way.
Apollo 14 Heads for Home (2020-02-01)

When leaving lunar orbit in February 1971, the crew of Apollo 14 watched this Earthrise from their command module Kitty Hawk. With Earth's sunlit crescent just peeking over the lunar horizon, the cratered terrain in the foreground is along the lunar farside. Of course, while orbiting the Moon, the crew could watch Earth rise and set, but the Earth hung stationary in the sky over Fra Mauro Base, their landing site on the lunar surface. Rock samples brought back by the Apollo 14 mission included a 20 pound rock nicknamed Big Bertha, later determined to contain a likely fragment of a meteorite from planet Earth.
Zeta Oph: Runaway Star (2020-02-02)

Like a ship plowing through cosmic seas, runaway star Zeta Ophiuchi produces the arcing interstellar bow wave or bow shock seen in this stunning infrared portrait. In the false-color view, bluish Zeta Oph, a star about 20 times more massive than the Sun, lies near the center of the frame, moving toward the left at 24 kilometers per second. Its strong stellar wind precedes it, compressing and heating the dusty interstellar material and shaping the curved shock front. What set this star in motion? Zeta Oph was likely once a member of a binary star system, its companion star was more massive and hence shorter lived. When the companion exploded as a supernova catastrophically losing mass, Zeta Oph was flung out of the system. About 460 light-years away, Zeta Oph is 65,000 times more luminous than the Sun and would be one of the brighter stars in the sky if it weren't surrounded by obscuring dust. The image spans about 1.5 degrees or 12 light-years at the estimated distance of Zeta Ophiuchi. Last week, NASA placed the Spitzer Space Telescope in safe mode, ending its 16 successful years of studying our universe.    News: NASA’s Spitzer Space Telescope Ends Mission of Astronomical Discovery
Solar Granules at Record High Resolution (2020-02-03)

Why does the Sun's surface keep changing?  The help find out, the US National Science Foundation (NSF) has built the Daniel K. Inouye Solar Telescope in Hawaii, USA. The Inouye telescope has a larger mirror that enables the capturing of images of higher resolution, at a faster rate, and in more colors than ever before.  Featured are recently-released first-light images taken over 10 minutes and combined into a 5-second time-lapse video.  The video captures an area on the Sun roughly the size of our Earth, features granules roughly the size of a country, and resolves features as small as 30-kilometers across. Granule centers are bright due to the upwelling hot solar plasma, while granule edges are dim due to the cooled plasma falling back.  Some regions between granules edges are very bright as they are curious magnetic windows into a deep and hotter solar interior.  How the Sun's magnetic field keeps changing, channeling energy, and affecting the distant Earth, among many other topics, will be studied for years to come using data from the new Inouye telescope.    Astrophysicists: Browse 2,100+ codes in the Astrophysics Source Code Library