omnianasa/nasa-apod-metadata huggingface dataset:
Messier 63: The Sunflower Galaxy (2008-04-17)
A bright spiral galaxy of the northern sky, Messier 63 is about 25 million light-years distant in the loyal constellation Canes Venatici. Also cataloged as NGC 5055, the majestic island universe is nearly 100,000 light-years across, about the size of our own Milky Way. Known by the popular moniker, The Sunflower Galaxy, M63 sports a bright yellowish core and sweeping blue spiral arms, streaked with cosmic dust lanes and dotted with pink star forming regions. But this deep exposure also shows remarkable faint loops and extensions of the galaxy's spiral arms. A dominant member of a known galaxy group, M63's faint extended features could be the result of gravitational interactions with nearby galaxies. M63 also shines across the electromagnetic spectrum and is thought to have undergone bursts of intense star formation.
IC 2948: The Running Chicken Nebula (2008-04-18)
Bright nebulae abound in and around the expansive southern constellation of Centaurus. This one, cataloged as IC 2948/2944 is near the star Lambda Centauri (just off the top of the frame) and not far on the sky from the better known Eta Carinae Nebula. Embedded in the reddish glowing cloud of hydrogen gas, typical of emission nebulae found in massive star-forming regions, is the energetic young star cluster Collinder 249. Seen in silhouette near the top of the view are small, dark clouds of obscuring cosmic dust. Called Thackeray's Globules for their discoverer, they are potential sites for the formation of new stars, but are likely being eroded by the intense radiation from the nearby young stars. Of course, gazing at the center of the region suggests to some IC 2948's popular name - The Running Chicken Nebula. The gorgeous skyscape spans about 70 light-years at the nebula's estimated 6,000 light-year distance.
Running Messier's Marathon (2008-04-19)
Gripped by an astronomical spring fever, many northern hemisphere stargazers embark on a Messier Marathon. Completing the marathon requires viewing all 110 objects in 18th century French astronomer Charles Messier's catalog in one glorious dusk-to-dawn observing run. As daunting as it sounds, there are often favorable weekend dates for completing the task that fall on nearly moonless nights near the March equinox. This colorful, six hour long time exposure of a group dedicated to running this year's Messier marathon includes celestial star trails along with terrestrial lighting trails from about 200 amateur astronomers. It was recorded from the isolated, ancient Bahram Palace in northern Iran's Kavir National Park. Astronomer and former Messier Marathon organizer for the ASIAC Babak Tafreshi offers this intriguing time-lapse movie (2MB wmv file) of the event.
Spiral Galaxies in Collision (2008-04-20)
Billions of years from now, only one of these two galaxies will remain.  Until then, spiral galaxies NGC 2207 and IC 2163 will slowly pull each other apart, creating tides of matter, sheets of  shocked gas, lanes of dark dust, bursts of star formation, and streams of cast-away stars.  Astronomers predict that NGC 2207, the larger galaxy on the left, will eventually incorporate IC 2163, the smaller galaxy on the right.  In the most recent encounter that peaked 40 million years ago, the smaller galaxy is swinging around counter-clockwise, and is now slightly behind the larger galaxy.  The space between stars is so vast that when galaxies collide, the stars in them usually do not collide.
Bacteriophages: The Most Common Life-Like Form on Earth (2008-04-21)
There are more bacteriophages on Earth than any other life-like form.  These small viruses are not clearly a form of life, since when not attached to bacteria they are completely dormant.  Bacteriophages attack and eat bacteria and have likely been doing so for over 3 billion years ago.  Although initially discovered early last century, the tremendous abundance of phages was realized more recently when it was found that a single drop of common seawater typically contains millions of them.  Extrapolating, phages are likely to be at least a billion billion (sic) times more numerous than humans. Pictured above is an electron micrograph of over a dozen bacteriophages attached to a single bacterium.  Phages are very small -- it would take about a million of them laid end-to-end to span even one millimeter.  The ability to kill bacteria makes phages a potential ally against bacteria that cause human disease, although bacteriophages are not yet well enough understood to be in wide spread medical use.
The Fox Fur Nebula from CFHT (2008-04-22)
This interstellar beast is formed of cosmic dust and gas interacting with the energetic light and winds from hot young stars.  The shape, visual texture, and color, combine to give the region the popular name Fox Fur Nebula. The characteristic blue glow on the left is dust reflecting light from the bright star S Mon, just beyond the left edge of the image. Mottled pink and brown areas are a combination of the cosmic dust and reddish emission from ionized hydrogen gas.  S Mon is part of a young open cluster of stars, NGC 2264, located about 2,500 light years away toward the constellation of Monoceros, just north of the Cone Nebula.
Above the Clouds (2008-04-23)
From the windswept peak of Mauna Kea, on the Big Island of Hawaii, your view of the world at night could look like this. At an altitude of about 13,500 feet, the mountain top is silhouetted in the stunning skyscape recorded near dusk in early December of 2005. The volcanic peak rises just above a sea of storm clouds illuminated by a bright Moon. Planet Venus is setting near the Moon as the brilliant evening star. The scene also includes the faint, milky band of our own galaxy's disk of stars and cosmic dust clouds stretching from the horizon into the sky along the right edge of the frame.
Cygnus Without Stars (2008-04-24)
The sky is full of hydrogen, though it can take a sensitive camera and telescope to see it. For example, this twelve-degree-wide view of the northern part of the constellation Cygnus reveals cosmic clouds of hydrogen gas along the plane of our Milky Way galaxy. The mosaic of telescopic images was recorded through an h-alpha filter that transmits only visible red light from glowing hydrogen atoms. Further digital processing has removed most of what is left of the myriad, point-like Milky Way stars from the scene, though bright Deneb, alpha star of Cygnus and head of the Northern Cross, remains near top center. Recognizable bright nebulae include NGC 7000 (North America Nebula), and IC 5070 (Pelican Nebula) at the upper left with IC 1318 (Butterfly Nebula) and NGC 6888 (Crescent Nebula) at lower right -- but others can be found throughout the wide field. Want the stars back? Just slide your cursor over the picture.
M86 in the Virgo Cluster (2008-04-25)
Bright lenticular galaxy M86 is near center of this cosmic view, at the heart of the Virgo Galaxy Cluster. Other bright galaxies in the neighborhood include M84 at the upper right, edge-on spiral NGC4388 near the right edge, a striking pair of interacting galaxies, Markarian's Eyes, in the lower left corner, and edge-on spiral NGC 4402 at about 11 o'clock. With well over a thousand members, the Virgo Cluster is the closest large cluster of galaxies. On average the cluster galaxies are measured to be about 50 million light-years away. The entire Virgo Cluster is difficult to appreciate because it covers such a large area, spanning over 10 degrees on the sky. This cluster close-up covers a region just under 1 degree wide or about 1.5 times the size of the full moon.
The Tarantula Zone (2008-04-26)
The Tarantula Nebula is more than 1,000 light-years in diameter -- a giant star forming region within our neighboring galaxy the Large Magellanic Cloud (LMC). That cosmic arachnid lies at the upper left of this expansive mosiac covering a part of the LMC over 6,000 light-years across. Within the Tarantula (NGC 2070), intense radiation, stellar winds and supernova shocks from the central young cluster of massive stars, cataloged as R136, energize the nebular glow and shape the spidery filaments. Around the Tarantula are other violent star-forming regions with young star clusters, filaments and bubble-shaped clouds. The small but expanding remnant of supernova 1987a, the closest supernova in modern history, is located near the center of the view. The rich field is about as wide as four full moons on the sky, located in the southern constellation Dorado.
The Galactic Center Radio Arc (2008-04-27)
What causes this unusual structure near the center of our Galaxy? The long parallel rays slanting across the top of the above radio image are known collectively as the Galactic Center Radio Arc and jut straight out from the Galactic plane.  The Radio Arc is connected to the Galactic center by strange curving filaments known as the Arches.  The bright radio structure at the bottom right likely surrounds a black hole at the Galactic center and is known as Sagittarius A*.  One origin hypothesis holds that the Radio Arc and the Arches have their geometry because they contain hot plasma flowing along lines of constant magnetic field.  Images from the Chandra X-ray Observatory appear to show this plasma colliding with a nearby cloud of cold gas.
Star Forming Region NGC 3582 (2008-04-28)
What's happening in the NGC 3582 nebula?  Bright stars and interesting molecules are forming. The complex nebula resides in the star forming region called RCW 57.  Visible in this image are dense knots of dark interstellar dust, bright stars that have formed in the past few million years, fields of glowing hydrogen gas ionized by these stars, and great loops of gas expelled by dying stars. A recent detailed study of NGC 3582 uncovered at least 33 massive stars in the end stages of formation, and the clear presence of the complex carbon molecules known as polycyclic aromatic hydrocarbons (PAHs). PAHs are thought to be created in the cooling gas of star forming regions, and their development in the Sun's formation nebula five billion years ago may have been an important step in the development of life on Earth. This picture was taken last year with the Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory (CTIO), in Chile.
Airplane Flight Patterns over the USA (2008-04-29)
What are these Earthlings going?  Millions of people move about planet Earth by airplane every day.  Hundreds of thousands of airplane flights take place over the US every day.  A dramatic graphical depiction of these flights was created by Aaron Koblin and is shown above.  Clicking on the above image will bring up a movie in many web browsers, a movie that might better be visible here. The movie depicts flight patterns that occurred over a few days in 2005 March.  The count on the lower left shows the number of USA-related flights at the time listed on the lower right.  The trails shown are not contrails but rather generated artificially by a computer algorithm. Major cities in North America and the USA are discernable. Inspection of the movie shows that some times of the day are busier than others, indicating that flights leave some destinations at times that are convenient for travelers. In terms of distance, flying to a distant location is much safer than driving to that location.  Flying in an airplane, however, remains slightly more dangerous than driving to a nearby airport.
Arp 272 (2008-04-30)
Linking spiral arms, two large colliding galaxies are featured in this Hubble Space Telescope view, part of a series of cosmic snapshots released to celebrate the Hubble's 18th anniversary. Recorded in astronomer Halton Arp's Atlas of Peculiar Galaxies as Arp 272, the pair is otherwise known as NGC 6050 and IC 1179. They lie some 450 million light-years away in the Hercules Galaxy Cluster. At that estimated distance, the picture spans over 150 thousand light-years. Although this scenario does look peculiar, galaxy collisions and their eventual mergers are now understood to be common, with Arp 272 representing a stage in this inevitable process. In fact, the nearby large spiral Andromeda Galaxy is known to be approaching our own galaxy and Arp 272 may offer a glimpse of the far future collision between Andromeda and the Milky Way.
The Giants of Omega Centauri (2008-05-01)
Globular star cluster Omega Centauri is some 15,000 light-years away and 150 light-years in diameter. Packed with about 10 million stars, Omega Cen is the largest of 200 or so known globular clusters that roam the halo of our Milky Way galaxy. This intriguing color picture combines a visible light image of the cluster in blue hues with infrared image data from the Spitzer Space Telescope. The Spitzer data includes images in two infrared bands, one shown in green and one in red. Both infrared bands are sensitive to light from the cool, giant stars in the cluster. Adding the red and green colors together creates yellow, showing off the cluster's giant stars as yellow spots. Of course, red spots also indicate cool, giant stars in the image, but some of the red spots are even more distant background galaxies. Also known simply as Red Giant Stars, they represent a stage in the life-cycle of stars more evolved than our own Sun, a stage the Sun will reach in about 5 billion years. Dust grains formed in the atmospheres of cool, giant stars are ultimately involved in the formation of other stars and planets.
Shaping NGC 6188 (2008-05-02)
Dark shapes with bright edges winging their way through dusty NGC 6188 are tens of light-years long. The emission nebula is found near the edge of an otherwise dark large molecular cloud in the southern constellation Ara, about 4,000 light-years away. Formed in that region only a few million years ago, the massive young stars of the embedded Ara OB1 association sculpt the fantastic shapes and power 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. A false-color Hubble palette was used to create the this gorgeous wide-field image and shows emission from sulfur, hydrogen, and oxygen atoms in red, green, and blue hues. At the estimated distance of NGC 6188, the picture spans about 300 light-years.
Alborz Mountain Milky Way (2008-05-03)
Snow-capped stratovolcano Mt. Damavand climbs to 5,670 meters (18,598 feet) near the left edge in this panoramic view of the world at night. In the sky to the left of Damavand's peak are the stars of the Big Dipper in Ursa Major. Pan to the right and your gaze will sweep across the arch of our Milky Way Galaxy above the Alborz Mountain Range bordering the Caspian Sea. Near the center of the panorama, recorded in the predawn hours of April 4th, bright stars Deneb and Altair lie close to the curve of the Milky Way, above the glow of the Haraz valley. Farther right, brilliant Jupiter dominates the sky near the stars, nebulae, and dark dust clouds toward the bulging galactic center. Finally, the horizon glow at the right edge, below bright yellowish giant star Antares, is from the city of Damavand, named for the legendary mountain peak.
An Antarctic Total Solar Eclipse (2008-05-04)
The Sun, the Moon, Antarctica, and two photographers all lined up in 2003  Antarctica during an unusual total eclipse of the Sun.  Even given the extreme location, a group of enthusiastic eclipse chasers ventured near the bottom of the world to experience the surreal momentary disappearance of the Sun behind the Moon.  One of the treasures collected was the above picture -- a composite of four separate images digitally combined to realistically simulate how the adaptive human eye saw the eclipse.  As the image was taken, both the Moon and the Sun peaked together over an Antarctic ridge.  In the sudden darkness, the magnificent corona of the Sun became visible around the Moon.  Quite by accident, another photographer was caught in one of the images checking his video camera.   Visible to his left are an equipment bag and a collapsible chair.
A Persistent Electrical Storm on Saturn (2008-05-05)
How do large storms evolve on Saturn? On Earth, a hurricane can persist for weeks, while the Great Red Spot on Jupiter has been in existence for over 150 years. On Saturn, a storm system has now set a new endurance record, now being discernable for greater than three months.  Electrical signals were detected from the storm in late November of 2007, while the above image was taken in early March 2008.  The storm has roughly the width of planet Earth.  Planetary scientists hypothesize that the storm runs deep into Saturn's cloud tops.  The above image is shown in exaggerated colors combining violet and green light with light normally too red for humans to see. Visible on the upper right are shadows of Saturn's expansive ring system.  Careful inspection will reveal Saturn's small moon Janus just below a ring shadow.  Understanding weather on other planets helps atmospheric scientists better understand our Earth's weather.  Observers of our Solar System's huge ringed world will be tracking the storm to see how it evolves and how long it will ultimately last.
Galaxies Collide in NGC 3256 (2008-05-06)
Galaxies don't normally look like this.  NGC 3256 actually shows a current picture of two galaxies that are slowly colliding.   Quite possibly, in hundreds of millions of years, only one galaxy will remain.  Today, however, NGC 3256 shows intricate filaments of dark dust, unusual tidal tails of stars, and a peculiar center that contains two distinct nuclei.  Although it is likely that no stars in the two galaxies will directly collide, the gas, dust, and ambient magnetic fields do interact directly.  NGC 3256, part of the vast Hydra-Centaurus supercluster of galaxies, spans over 100 thousand light-years across and is located about 100 million light-years away.
The Gegenschein Over Chile (2008-05-07)
Is the night sky darkest in the direction opposite the Sun? No. In fact, a rarely discernable faint glow known as the gegenschein (German for "counter glow") can be seen 180 degrees around from the Sun in an extremely dark sky. The gegenschein is sunlight back-scattered off small interplanetary dust particles.  These dust particles are millimeter sized splinters from asteroids and orbit in the ecliptic plane of the planets.  Pictured above from last October is one of the most spectacular pictures of the gegenschein yet taken. Here a deep exposure of an extremely dark sky over Paranal Observatory in Chile shows the gegenschein so clearly that even a surrounding glow is visible.   In the foreground are several of the European Southern Observatory's Very Large Telescopes, while notable background objects include the Andromeda galaxy toward the lower left and the Pleiades star cluster just above the horizon.  The gegenschein is distinguished from zodiacal light near the Sun by the high angle of reflection.  During the day, a phenomenon similar to the gegenschein called the glory can be seen in reflecting air or clouds opposite the Sun from an airplane.
The Dark Tower in Scorpius (2008-05-08)
In silhouette against a crowded star field toward the constellation Scorpius, this dusty cosmic cloud evokes for some the image of an ominous dark tower. In fact, clumps of dust and molecular gas collapsing to form stars may well lurk within the dark nebula, a structure that spans almost 40 light-years across the gorgeous telescopic view. Known as a cometary globule, the swept-back cloud, extending from the upper right to the head (top of the tower) left and below center, is shaped by intense ultraviolet radiation from the OB association of very hot stars in NGC 6231, off the left edge of the scene. That energetic ultraviolet light also powers the globule's bordering reddish glow of hydrogen gas. Hot stars embedded in the dust can be seen as small bluish reflection nebulae. This dark tower, NGC 6231, and associated nebulae are about 5,000 light-years away.
Moon Meets Mercury (2008-05-09)
On Tuesday, May 6, while standing on planet Earth and sweeping your binoculars along the western horizon just after sunset, you might have encountered this arresting skyscape. The view features a slender crescent Moon and bright planet Mercury separated on the sky by only about 2 degrees. Cradled in the sunlit lunar crescent, the night side of the Moon is faintly illuminated by earthshine -- sunlight reflected from planet Earth. Of course, the clouds in silhouette and fading twilight colors are common elements in pictures of the sky after sunset, but much less often seen is inner planet Mercury, usually hiding close to the Sun in Earth's sky. Still, the coming week will be a good time to spot Mercury near the western horizon about 30 minutes after sunset. As for the Moon, tonight and tomorrow night the crescent Moon will wander close to Mars in the early evening sky.
Stars and Mars (2008-05-10)
Wandering through the evening sky, on May 4th planet Mars stood in line with Castor and Pollux, the two bright stars of the constellation Gemini.  In this time exposure of the celestial alignment, Mars actually takes on a distinct yellowish hue, contrasting in color with Pollux; a giant star known to have a Jupiter-class planet, and Castor; itself a multiple star system. Though in mythology Pollux and Castor are twin brothers, the two stars are physically unrelated and are about 34 and 50 light-years distant respectively. Included in the skyview are Procyon, alpha star of Canis Minor, and famous star cluster M44 also known as the Beehive Cluster. Dust in our own solar system reflecting sunlight creates the faint band of Zodiacal light emerging from the lower right corner of the frame. Just put your cursor over the picture for help with identifications. Of course, bright Mars can still be found in the western evening skies and tonight wanders near the crescent Moon.
Retrograde Mars (2008-05-11)
Why would Mars appear to move backwards?  Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars.  About every two years, however, the Earth passes Mars as they orbit around the Sun.  During the most recent such pass over the last year, the proximity of Mars made the red planet appear larger and brighter than usual.  Also during this time, Mars appeared to move backwards in the sky, a phenomenon called retrograde motion.  Pictured above is a series of images digitally stacked so that all of the stars images coincide.  Here, Mars appears to trace out a loop in the sky.  Near the top of the loop, Earth passed Mars and the retrograde motion was the highest.  Retrograde motion can also be seen for other Solar System planets.
The M81 Galaxy Group Through the Integrated Flux Nebula (2008-05-12)
Large galaxies and faint nebulae highlight this deep image of the M81 Group of galaxies.  First and foremost in the wide-angle 12-hour exposure is the grand design spiral galaxy M81, the largest galaxy visible in the image.  M81 is gravitationally interacting with M82 just below it, a big galaxy with an unusual halo of filamentary red-glowing gas.  Around the image many other galaxies from the M81 Group of galaxies can be seen.  Together with other galaxy congregates including our Local Group of galaxies and the Virgo Cluster of galaxies, the M81 Group is part of the expansive Virgo Supercluster of Galaxies.  This whole galaxy menagerie is seen through the faint glow of an Integrated Flux Nebula, a little studied complex of diffuse gas and dust clouds in our Milky Way Galaxy.