omnianasa/nasa-apod-metadata huggingface dataset:
Grand Spiral Galaxy NGC 1232 (2008-08-24)
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 new 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.  Invisible are even greater amounts of matter in a form we don't yet know - pervasive dark matter needed to explain the motions of the visible in the outer galaxy.  What's out there?    Announcement: APOD Editor RJN to open Final Frontier art exhibit in Ireland on August 28
NGC 7008: The Fetus Nebula (2008-08-25)
Compact and round, NGC 7008 is recognized as a planetary nebula about 2,800 light-years distant in the nebula rich constellation of Cygnus. This impressive telescopic view shows off NGC 7008's remarkable colors and details by the skillful combination of broad band and narrow band images from two different telescopes with about 12 hours of total exposure time. The intriguing assortment of features within the nebula's approximately 1 light-year diameter suggest its popular name, the Fetus Nebula, but planetary nebulae are not associated with star birth. Instead, nebulae like NGC 7008 are produced during a brief phase that sun-like stars pass through toward the end of their lives. Ejecting their outer layers, the stars cool to eventually become white dwarf stars, like the star seen near the center of NGC 7008. This colorful image also includes an unrelated but still lovely gold and blue binary star system just below NGC 7008.    Announcement: APOD Editor RJN to open Final Frontier art exhibit in Ireland on August 28
47 Tuc: A Great Globular Cluster of Stars (2008-08-26)
Stars come in bunches. Of the over 200 globular star clusters that orbit the center of our Milky Way Galaxy, 47 Tucanae is the second brightest globular cluster (behind Omega Centauri).  Light takes about 13,000 years to reach us from 47 Tuc which can be seen on the sky near the Small Magellanic Cloud in the southern constellation of Tucana.  Also known as NGC 104, the dense cluster is made up of several million stars in a volume only about 120 light-years across. The cluster's red giant stars are particularly easy to see in this picture.  The globular cluster is also home to exotic x-ray binary star systems.    Announcement: APOD Editor RJN to open Final Frontier art exhibit in Ireland on August 28
IC 5146: The Cocoon Nebula (2008-08-27)
Inside the Cocoon Nebula is a newly developing cluster of stars. Cataloged as IC 5146, the beautiful nebula is nearly 15 light-years wide, located some 4,000 light years away toward the northern constellation Cygnus. Like other star forming regions, it stands out in red, glowing, hydrogen gas excited by young, hot stars and blue, dust-reflected starlight at the edge of an otherwise invisible molecular cloud. In fact, the bright star near the center of this nebula is likely only a few hundred thousand years old, powering the nebular glow as it clears out a cavity in the molecular cloud's star forming dust and gas. This color view of the Cocoon Nebula traces remarkably subtle features within and surrounding the dusty stellar nursery.    Announcement: APOD Editor RJN to open Final Frontier art exhibit in Ireland on August 28
Fermi's First Light (2008-08-28)
Launched on June 11 to explore the universe at extreme energies, the Gamma-ray Large Area Space Telescope has been officially renamed the Fermi Gamma-ray Space Telescope, in honor of Nobel Laureate Enrico Fermi (1901-1954), pioneer in high-energy physics. After testing, Fermi's two instruments, the Gamma-ray Burst Monitor (GBM) and the Large Area Telescope (LAT), are now regularly returning data. Fermi's first map of the gamma-ray sky from the LAT is shown in this false-color image, an all-sky view that looks toward the center of our Milky Way Galaxy with the galactic plane projected across the middle. What shines in the gamma-ray sky? Along the galactic plane, energetic cosmic rays collide with gas and dust to produce the diffuse gamma-ray glow. Strong emission from spinning neutron stars or pulsars, and distant active galaxies known as blazars, can be identified by placing your cursor over the map. A prelude to future discoveries, the remarkable result combines only 4 days of observations, equivalent to a year of observations with the Compton Gamma-ray Observatory mission of the 1990s. In addition to the ability to monitor gamma-ray bursts, the greatly improved sensitivity will allow Fermi to look deeper into the high-energy Universe.
Generations of Stars in W5 (2008-08-29)
Giant star forming region W5 is over 200 light-years across and about 6,500 light-years away in the constellation Cassiopeia. W5's sculpted clouds of cold gas and dust seem to form fantastic shapes in this impressive mosaic of infrared images from the Spitzer Space Telescope. In fact, the area on the right includes the structures previously dubbed the Mountains of Creation. New evidence indicates that successive generations of stars formed in the W5 region in an expanding pattern of triggered star formation. The older, earlier generations of stars seem to cluster near the middle of the enormous cavities, with younger stars seen near the rims. Winds and radiation from the older, central stars likely carve out and compress surrounding interstellar material, triggering the collapse that gave rise to younger, later generations of stars farther out. In the false-color image, heated dust still within the cavities appears red, while the youngest stars are forming in the whitish areas. W5 is also known as IC 1848, and together with IC 1805 it is part of a complex region popularly dubbed the Heart and Soul Nebulae.
The View from Everest (2008-08-30)
What would it be like to stand atop the tallest mountain on Earth?  To see a full panoramic vista from there, scroll right.  Visible are snow peaked mountains near and far, tremendous cliffs, distant plateaus, the tops of clouds, and a dark blue sky.   Mt. Everest stands 8.85 kilometers above sea level, roughly the maximum height reached by international airplane flights, but much less than the 300 kilometers achieved by a space shuttle.  Hundreds of people have tried and failed to climb the behemoth by foot, a feat first accomplished successfully in 1953.  About 1000 people have now made it to the summit.  Roddy Mackenzie, who climbed the mountain in 1989, captured the above image. Mt. Everest lies in the Himalaya mountains in the country of Nepal.  In the native language of Nepal, the mountain's name is "Sagarmatha" which means "forehead of the sky."
Eclipse over the Great Wall (2008-08-31)
Contrary to the famous myth, you can't see the Great Wall of China from the Moon ... even during a total solar eclipse. But on August 1 you could see the Moon eclipsing the Sun from the Great Wall. In fact, from this location near the Great Wall's western end, the Moon completely blocked the Sun's overwhelming disk revealing a shimmering solar corona and bright planets in the briefly darkened sky. A main pass, The Great Wall's Jiayuguan Fort, is also silhouetted in the foreground. The pass is the western-most of the wall's passes and the best preserved, initially built around 1372 during the Ming dynasty. The nearby city of Jiayuguan in Gansu Province was an important stop on the Silk Road.
CG4: A Ruptured Cometary Globule (2008-09-01)
Can a gas cloud grab a galaxy?  It's not even close.  The "claw" of this odd looking "creature" in the above photo is a gas cloud known as a cometary globule.  This globule, however, has ruptured.  Cometary globules are typically characterized by dusty heads and elongated tails.  These features cause cometary globules to have visual similarities to comets, but in reality they are very much different.  Globules are frequently the birthplaces of stars, and many show very young stars in their heads. The reason for the rupture in the head of this object is not completely known.  The galaxy to the left of the globule is huge, very far in the distance, and only placed near CG4 by chance superposition.
NGC 1316: After Galaxies Collide (2008-09-02)
Astronomers turn detectives when trying to figure out the cause of startling sights like NGC 1316.  Their investigation indicates that NGC 1316 is an enormous elliptical galaxy that started, about 100 million years ago, to devour a smaller spiral galaxy neighbor, NGC 1317, just above it. Supporting evidence includes the dark dust lanes characteristic of a spiral galaxy, and faint swirls of stars and gas visible in this wide and deep image. What remains unexplained are the unusually small globular star clusters, seen as faint dots on the image. Most elliptical galaxies have more and brighter globular clusters than NGC 1316.  Yet the observed globulars are too old to have been created by the recent spiral collision. One hypothesis is that these globulars survive from an even earlier galaxy that was subsumed into NGC 1316.
31 Million Miles from Planet Earth (2008-09-03)
On July 4th, 2005, the Deep Impact spacecraft directed a probe to impact the nucleus of Comet Tempel 1. Still cruising through the solar system, earlier this year the robotic spacecraft looked back to record a series of images of its home world 31 million miles (50 million kilometers) away. In a sequence from top left to bottom right, these four frames from the video show a rotating Earth. They combine visible and near-infrared image data with enough resolution and contrast to see clouds, oceans, and continents. They also follow a remarkable transit of Earth by its large, natural satellite, the Moon. The Moon's orbital motion carries it across the field of view from left to right. Imaging the Earth from this distant perspective allows astronomers to connect overall variations in brightness at different wavelengths with planetary features. The observations will aid in the search for earthlike planets in other planetary systems.
Spokes in the Helix Nebula (2008-09-04)
At first glance, the Helix Nebula (aka NGC 7293), looks simple and round. But this well-studied example of a planetary nebula, produced near the end of the life of a sun-like star, is now understood to have a surprisingly complex geometry. Its extended loops and comet-shaped features have been explored in Hubble Space Telescope images. Still, a 16-inch diameter telescope and camera with broad and narrow band filters was used to create this sharp view of the Helix. The color composite also reveals the nebula's intriguing details, including light-year long, bluegreen radial stripes or spokes that give it the appearance of a cosmic bicycle wheel. The spoke features seem to indicate that the Helix Nebula is itself an old and evolved planetary nebula. The Helix is a mere seven hundred light years from Earth, in the constellation Aquarius.
Milky Way Road Trip (2008-09-05)
In search of planets and the summer Milky Way, astronomer Tunç Tezel took an evening road trip. Last Saturday, after driving the winding road up Uludag, a mountain near Bursa, Turkey, he was rewarded by this beautiful skyview to the south. Near the center, bright planet Jupiter outshines the city lights below and the stars of the constellation Sagittarius. Above the mountain peaks, an arcing cloud bank seems to lead to the Milky Way's own cloudy apparition plunging into the distant horizon. In Turkish, Uludag means Great Mountain. Uludag was known in ancient times as the Mysian Olympus.
A Flock of Stars (2008-09-06)
Only a few stars can be found within ten light-years of our lonely Sun, situated near an outer spiral arm of the Milky Way galaxy. But if the Sun were found within one of our galaxy's star clusters, thousands of stars might occupy a similar space. What would the night sky look like in such a densely packed stellar neighborhood? When Roger Hopkins took this picture at the Montezuma National Wildlife Refuge in the Finger Lakes region of western New York, USA, he was struck by this same notion. Appropriately, he had photographed a flock of starlings against the backdrop of a serene sunset. He then manipulated the image so that the black bird silhouettes were changed to white. The final picture dramatically suggests the tantalizing spectacle of approaching night in crowded skies above a cluster star world.
Searching for Meteorites in Antarctica (2008-09-07)
Where is the best place on Earth to find meteorites? Although meteors fall all over the world, they usually just sink to the bottom of an ocean, are buried by shifting terrain, or are easily confused with terrestrial rocks. At the bottom of the Earth, however, in East Antarctica, huge sheets of blue ice remain pure and barren. When traversing such a sheet, a dark rock will stick out. These rocks have a high probability of being true meteorites -- likely pieces of another world. An explosion or impact might have catapulted these meteorites from the Moon, Mars, or even an asteroid, yielding valuable information about these distant worlds and our early Solar System. Small teams of snowmobiling explorers so far have found thousands. Pictured above, ice-trekkers search a field 25-kilometers in front of Otway Massif in the Transantarctic Mountain Range during the Antarctic summer of 1995-1996.
Rosetta Spacecraft Passes Asteroid Steins (2008-09-08)
What's that diamond in the sky? Cruising though space, sometimes you'll come across an unusual object. Such was the case on Friday for ESA's Rosetta spacecraft on its way to comet Churyumov-Gerasimenko in 2014. Robotic Rosetta buzzed right by the main belt asteroid 2867 �teins, taking many pictures, some of which have been compiled into a short video. At first glance, Steins looked like a 5-kilometer wide diamond, but as Rosetta shot by, craters and a more extended shape become evident. In the above sequence of six images, a notable chain of craters is evident vertically on the asteroid's surface, most probably caused by a chance collision with a stream of meteors. Space scientists will now study the data taken by Rosetta of asteroid Steins in an effort to better understand its composition, origin, and why the asteroid reflects light so well. As the Earth-bound scientists toil, Rosetta itself will continue to zoom across our Solar System, next swooping again by the Earth in 2009 November, flying by asteroid 21 Lutetia in 2010 July, and finally landing on comet Churyumov-Gerasimenko in 2014 November.
M110: Satellite of the Andromeda Galaxy (2008-09-09)
Our Milky Way Galaxy is not alone. It is part of a gathering of about 25 galaxies known as the Local Group. Members include the Great Andromeda Galaxy (M31), M32, M33, the Large Magellanic Cloud, the Small Magellanic Cloud, Dwingeloo 1, several small irregular galaxies, and many dwarf elliptical and dwarf spheroidal galaxies. Pictured on the lower right is one of the dwarf ellipticals: NGC 205. Like M32, NGC 205 is a companion to the large M31, and can sometimes be seen to the south of M31's center in photographs. The image shows NGC 205 to be unusual for an elliptical galaxy in that it contains at least two dust clouds (at 9 and 2 o'clock - they are visible but hard to spot) and signs of recent star formation. This galaxy is sometimes known as M110, although it was actually not part of Messier's original catalog.
The Anthe Arc around Saturn (2008-09-10)
What created this unusual partial ring around Saturn?  Discovered last year, the arc was captured in clear detail only two months ago by the Saturn-orbiting Cassini spacecraft.  Since the arc occupies the same orbit as the small moon Anthe, a leading hypothesis holds that the arc was created by, and is replenished by, meteor impacts on Anthe.  Similar arcs have been previously discovered, including an arc associated with the small Saturnian moon Methone, one arc related to Saturn's G ring, and several arcs orbiting Neptune.  Pictured above, Anthe, only two kilometers across, is seen as the bright point near the top of the Anthe arc. The Anthe arc was imaged by the robotic space probe as it swooped to within 1.5 million kilometers of the small moon.
Mountain Top Meteors (2008-09-11)
A mountain top above the clouds and light-polluted cities was a good place to go to watch this August's Perseid meteor shower. In fact, this composite picture from one of the highest points in Romania, the Omu summit (2,507 meters) in the Southern Carpathian Mountains, captures about 20 of the shower's bright streaks against a starry night sky. The cosmic debris stream that creates the shower is composed of dust particles moving along parallel paths, following the orbit of their parent comet Swift-Tuttle. Looking toward the shower's radiant point in the constellation Perseus, perspective causes the parallel meteor streaks to appear to diverge. But looking directly away from the radiant point, as in this view, perspective actually makes the Perseid meteors seem to be converging toward a point below the horizon.
Planets over Perth (2008-09-12)
A bright trio of terrestrial planets was joined by a young Moon on September 1st, in planet Earth's early evening skies. In this view of the celestial gathering from Perth, Western Australia, the Moon's sunlit crescent is nearly horizontal at Perth's southern latitude of about 32 degrees. Venus, then Mercury, and finally Mars shine above colorful city lights on the far shore of the Swan River. The six unlit towers on the left surround a large cricket stadium. For now, the planetary trio still lingers low in the west just after sunset. But in the coming days Venus will move farther from the Sun, climbing higher after sunset, while Mercury and Mars will steadily sink into the glare along the western horizon.   Note: Free Astronomy Course Taught Online by an APOD Editor
M33: Triangulum Galaxy (2008-09-13)
The small, northern constellation Triangulum harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy. M33 is over 50,000 light-years in diameter, third largest in the Local Group of galaxies after the Andromeda Galaxy (M31), and our own Milky Way. About 3 million light-years from the Milky Way, M33 is itself thought to be a satellite of the Andromeda Galaxy and astronomers in these two galaxies would likely have spectacular views of each other's grand spiral star systems. As for the view from planet Earth, this sharp, detailed image nicely shows off M33's blue star clusters and pinkish star forming regions that trace the galaxy's loosely wound spiral arms. In fact, the cavernous NGC 604 is the brightest star forming region, seen here at about the 1 o'clock position from the galaxy center. Like M31, M33's population of well-measured variable stars have helped make this nearby spiral a cosmic yardstick for establishing the distance scale of the Universe.   Note: Free Astronomy Course Taught Online by an APOD Editor
The Heart and Soul Nebulas (2008-09-14)
Is the heart and soul of our Galaxy located in Cassiopeia?  Possibly not, but that is where two bright emission nebulas nicknamed Heart and Soul can be found.  The Heart Nebula, officially dubbed IC 1805 and visible in the above zoomable view on the right, has a shape reminiscent of a classical heart symbol.  Both nebulas shine brightly in the red light of energized hydrogen.  Several young open clusters of stars populate the image and are visible above in blue, including the nebula centers.  Light takes about 6,000 years to reach us from these nebulas, which together span roughly 300 light years.  Studies of stars and clusters like those found in the  Heart and Soul Nebulas have focussed on how massive stars form and how they affect their environment.   Note: Free Astronomy Course Taught Online by an APOD Editor
SN 1006: A Supernova Ribbon from Hubble (2008-09-15)
What created this unusual space ribbon?  Most assuredly, one of the most violent explosions ever witnessed by ancient humans. Back in the year 1006 AD, light reached Earth from a stellar explosion in the constellation of the Wolf (Lupus), creating a "guest star" in the sky that appeared brighter than Venus and lasted for over two years. The supernova, now cataloged at SN 1006, occurred about 7,000 light years away and has left a large remnant that continues to expand and fade today.  Pictured above is a small part of that expanding supernova remnant dominated by a thin and outwardly moving shock front that heats and ionizes surrounding ambient gas. SN 1006 now has a diameter of nearly 60 light years.  Within the past year, an even more powerful explosion occurred far across the universe that was visible to modern humans, without any optical aid, for a few seconds.   Note: Free Astronomy Course Taught Online by an APOD Editor
W5: Pillars of Star Creation (2008-09-16)
How do stars form? A study of star forming region W5 by the sun-orbiting Spitzer Space Telescope provides clear clues by recording that massive stars near the center of empty cavities are older than stars near the edges.  A likely reason for this is that the older stars in the center are actually triggering the formation of the younger edge stars.  The triggered star formation occurs when hot outflowing gas compresses cooler gas into knots dense enough to gravitationally contract into stars. Spectacular pillars, left slowly evaporating from the hot outflowing gas, provide further visual clues. In the above scientifically-colored infrared image, red indicates heated dust, while white and green indicate particularly dense gas clouds. W5 is also known as IC 1848, and together with IC 1805 form a complex region of star formation popularly dubbed the Heart and Soul Nebulas. The above image highlights a part of W5 spanning about 2,000 light years that is rich in star forming pillars.  W5 lies about 6,500 light years away toward the constellation of Cassiopeia.   Note: Free Astronomy Course Taught Online by an APOD Editor
MACSJ0025: Two Giant Galaxy Clusters Collide (2008-09-17)
What happens when two of the largest objects in the universe collide? No one was quite sure, but the answer is giving clues to the nature of mysterious dark matter. In the case of MACSJ0025.4-1222, two huge clusters of galaxies have been found slowly colliding over hundreds of millions of years, and the result has been imaged by both the Hubble Space Telescope in visible light and the Chandra Space Telescope in X-ray light. Once the above visible image was recorded, the location and gravitational lens distortions of more distant galaxies by the newly combined galaxy cluster allowed astronomers to computationally determine what happened to the clusters' dark matter. The result indicates that this huge collision has caused the dark matter in the clusters to become partly separated from the normal matter, confirming earlier speculation. In the above combined image, dark matter is shown as the diffuse purple hue, while a smoothed depiction of the X-ray hot normal matter is shown in pink.  MACSJ0025 contains hundreds of galaxies, spans about three million light years, and lies nearly six billion light years away (redshift 0.59) toward the constellation of Monster Whale (Cetus).   Note: Free Astronomy Course Taught Online by an APOD Editor