Astronomy Picture of the Day (General/Chat)

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  • Astronomy Picture of the Day -- Lick Observatory Moonrise

    03/10/2012 9:36:43 AM PST · by SunkenCiv · 27 replies
    NASA ^ | March 10, 2012 | (see photo credit)
    Explanation: As viewed from a well chosen location at sunset, the gorgeous Full Moon rose behind Mount Hamilton, east of San Jose, California on March 7. The lunar disk frames historic Lick Observatory perched on the mountain's 4,200 foot summit. Both observatory and Moon echo the warm color of sunlight (moonlight is reflected sunlight) filtered by a long path through the atmosphere. Substantial atmospheric refraction contributes the Moon's ragged, green rim. Of course, the March Full Moon is also known as the Full Worm Moon. In the telescopic photo, Lick's 40 inch Nickel Telescope dome is on the left. The...
  • Astronomy Picture of the Day -- NGC 1579: Trifid of the North

    03/09/2012 4:35:28 AM PST · by SunkenCiv · 12 replies
    NASA ^ | March 09, 2012 | (see photo credit)
    Explanation: Colorful NGC 1579 resembles the better known Trifid Nebula, but lies much farther north in planet Earth's sky, in the heroic constellation Perseus. About 2,100 light-years away and 3 light-years across, NGC 1579 is, like the Trifid, a study in contrasting blue and red colors, with dark dust lanes prominent in the nebula's central regions. In both, dust reflects starlight to produce beautiful blue reflection nebulae. But unlike the Trifid, in NGC 1579 the reddish glow is not emission from clouds of glowing hydrogen gas excited by ultraviolet light from a nearby hot star. Instead, the dust in NGC...
  • Astronomy Picture of the Day -- The Seagull Nebula

    03/08/2012 3:00:48 PM PST · by SunkenCiv · 10 replies
    NASA ^ | March 08, 2012 | (see photo credit)
    Explanation: A broad expanse of glowing gas and dust presents a bird-like visage to astronomers from planet Earth, suggesting its popular moniker -- The Seagull Nebula. This portrait of the cosmic bird covers a 1.6 degree wide swath across the plane of the Milky Way, near the direction of Sirius, alpha star of the constellation Canis Major. Of course, the region includes objects with other catalog designations: notably NGC 2327, a compact, dusty emission region with an embedded massive star that forms the bird's head (aka the Parrot Nebula, above center). IC 2177 forms the sweeping arc of the seagull's...
  • Astronomy Picture of the Day -- Conjunction Over Reunion Island

    03/06/2012 9:15:48 PM PST · by SunkenCiv · 5 replies
    NASA ^ | March 06, 2012 | (see photo credit)
    Explanation: You don't have to be on Reunion Island to see this week's planetary conjunction. Only if you want to see this picturesque seascape as well. To see the conjunction from just about anywhere in the world, look to the west after sunset. The first planet you may notice is Venus, the brightest object in the western sky. Above Venus, the second brightest object is Jupiter. The hardest planet to spot is Mercury, which is visible only briefly after sunset as a faint dot just above the horizon. Picturesque rocks leading out from Reunion Island to the Indian Ocean populate...
  • Astronomy Picture of the Day -- NGC 2170: Celestial Still Life

    03/06/2012 9:10:12 PM PST · by SunkenCiv · 1 replies
    NASA ^ | March 06, 2012 | (see photo credit)
    Explanation: Is this a painting or a photograph? In this beautiful celestial still life composed with a cosmic brush, dusty nebula NGC 2170 shines near the image center. Reflecting the light of nearby hot stars, NGC 2170 is joined by other bluish reflection nebulae, a red emission region, many dark absorption nebulae, and a backdrop of colorful stars. Like the common household items still life painters often choose for their subjects, the clouds of gas, dust, and hot stars pictured above are also commonly found in this setting -- a massive, star-forming molecular cloud in the constellation of the Unicorn...
  • Astronomy Picture of the Day -- Flying Over the Earth at Night

    03/06/2012 9:06:45 PM PST · by SunkenCiv · 8 replies · 1+ views
    NASA ^ | March 05, 2012 | (see photo credit)
    Explanation: Many wonders are visible when flying over the Earth at night. A compilation of such visual spectacles was captured recently from the International Space Station (ISS) and set to rousing music. Passing below are white clouds, orange city lights, lightning flashes in thunderstorms, and dark blue seas. On the horizon is the golden haze of Earth's thin atmosphere, frequently decorated by dancing auroras as the video progresses. The green parts of auroras typically remain below the space station, but the station flies right through the red and purple auroral peaks. Solar panels of the ISS are seen around the...
  • Astronomy Picture of the Day -- Warped Spiral Galaxy ESO 510-13

    03/04/2012 5:32:30 AM PST · by SunkenCiv · 14 replies
    NASA ^ | March 04, 2012 | (see photo credit)
    Explanation: How did spiral galaxy ESO 510-13 get bent out of shape? The disks of many spirals are thin and flat, but not solid. Spiral disks are loose conglomerations of billions of stars and diffuse gas all gravitationally orbiting a galaxy center. A flat disk is thought to be created by sticky collisions of large gas clouds early in the galaxy's formation. Warped disks are not uncommon, though, and even our own Milky Way Galaxy is thought to have a small warp. The causes of spiral warps are still being investigated, but some warps are thought to result from interactions...
  • Astronomy Picture of the Day -- Another Tail for Comet Garradd

    03/03/2012 1:33:33 PM PST · by SunkenCiv · 13 replies
    NASA ^ | March 03, 2012 | (see photo credit)
    Explanation: Remarkable comet Garradd (C2009/P1) has come to be known for two distinctive tails. From the perspective of earthbound comet watchers the tails are visible on opposite sides of its greenish coma. Seen here in a telescopic view, the recognizable dust tail fans out to the right, trailing the comet nucleus in its orbit. Streaming away from the sunward direction, a familiar bluish ion tail sweeps to the left. But the comet also seems to have, at least temporarily, sprouted a second ion tail recorded in this image from February 24. Other comet imagers have recently captured changing structures in...
  • Astronomy Picture of the Day -- Jupiter Unplugged

    03/02/2012 3:53:19 AM PST · by SunkenCiv · 7 replies · 279+ views
    NASA ^ | March 02, 2012 | (see photo credit)
    Explanation: Five hand drawn sketches of Jupiter were used to create this beautifully detailed flat map of the ruling gas giant's turbulent cloud tops. Made with colored pencils at the eyepiece of a 16 inch diameter telescope, the original drawings are about 5 inches (12.5 cm) in diameter. The drawn planisphere map dimensions are 16x8 inches (40x20 cm). Observing on different dates in November and December of 2011, astronomical artist Fred Burgeot has relied on Jupiter's rotation to cover the planet's complete circumference. Digital animator Pascal Chauvet has also translated Burgeot's drawings into an intriguing video (vimeo), synthesizing a telescopic...
  • Astronomy Picture of the Day -- Multicolor Venus

    02/29/2012 9:13:06 PM PST · by SunkenCiv · 7 replies · 2+ views
    NASA ^ | March 01, 2012 | (see photo credit)
    Explanation: Brilliant Venus now shines in western skies at twilight. Seen as the prominent evening star, the planet is a tantalizing celestial beacon even for casual skygazers. Venus can offer less than satisfying telescopic views though. The planet is shrouded in reflective clouds that appear bright but featureless at the eyepiece. Still, careful imaging with a series of color filters, as used in these composite images, can reveal subtle cloud patterns. Captured early last month from a backyard observatory in Manchester, New Hampshire, USA, the images are based on video camera frames. The data was recorded through near-ultraviolet, green, and...
  • Astronomy Picture of the Day -- Moon and Planets Over Catalonia

    02/29/2012 4:19:35 AM PST · by SunkenCiv · 3 replies · 1+ views
    NASA ^ | February 29, 2012 | (see photo credit)
    Explanation: Venus and Jupiter will appear unusually close in the sky over the next month. The planetary conjunction will be easily visible to the unaided eye because Venus will appear brighter than any background star, and Jupiter will be nearly as bright. To see the near-alignment, simply look to the west after sunset. At their closest, on March 15, the two planets will appear only about three degrees apart. The planets will not be significantly closer in space - Venus will just be passing nearly in front of Jupiter as seen from the Earth. In the above image composite taken...
  • Astronomy Picture of the Day -- The Opposing Tails of Comet Garradd

    02/29/2012 4:17:52 AM PST · by SunkenCiv · 8 replies
    NASA ^ | February 28, 2012 | (see photo credit)
    Explanation: Why does Comet Garradd have two tails? Visible on the left, Comet Garradd's dust tail is composed of ice and dust bits that trail the comet in its orbit around the Sun. Visible on the right, Comet Garradd's ion tail, is composed of ionized gas blown directly out from the Sun by the solar wind. Most comets show two tails, although it is unusual for them to appear to point in nearly opposite directions. Comet Garradd is currently showing opposing tails because of the Earth's opportunistic intermediate viewing angle. Subtle hues in the above image captured last week show...
  • Astronomy Picture of the Day -- Shocked by Supernova 1987A

    02/27/2012 3:47:43 PM PST · by SunkenCiv · 12 replies
    NASA ^ | February 27, 2012 | (see photo credit)
    Explanation: Twenty five years ago, the brightest supernova of modern times was sighted. Over time, astronomers have watched and waited for the expanding debris from this tremendous stellar explosion to crash into previously expelled material. A clear result of such a collision is demonstrated in the above time lapse video of images recorded by the Hubble Space Telescope between 1994 and 2009. The movie depicts the collision of an outward moving blast wave with the pre-existing, light-year wide ring. The collision occurred at speeds near 60 million kilometers per hour and shock-heats the ring material causing it to glow. Astronomers...
  • Astronomy Picture of the Day -- The Mysterious Rings of Supernova 1987A

    02/25/2012 9:18:33 PM PST · by SunkenCiv · 11 replies
    NASA ^ | February 26, 2012 | (see photo credit)
    Explanation: What's causing those odd rings in supernova 1987A? Twenty five years ago, in 1987, the brightest supernova in recent history was seen in the Large Magellanic Clouds. At the center of the above picture is an object central to the remains of the violent stellar explosion. Surrounding the center are curious outer rings appearing as a flattened figure 8. Although large telescopes including the Hubble Space Telescope monitor the curious rings every few years, their origin remains a mystery. Pictured above is a Hubble image of the SN1987A remnant taken last year. Speculation into the cause of the rings...
  • Astronomy Picture of the Day -- Stephan's Quintet

    02/25/2012 7:44:12 AM PST · by SunkenCiv · 7 replies
    NASA ^ | February 25, 2012 | (see photo credit)
    Explanation: The first identified compact galaxy group, Stephan's Quintet is featured in this eye-catching image constructed with data drawn from the extensive Hubble Legacy Archive. About 300 million light-years away, only four of these five galaxies are actually locked in a cosmic dance of repeated close encounters. The odd man out is easy to spot, though. The interacting galaxies, NGC 7319, 7318A, 7318B, and 7317 have an overall yellowish cast. They also tend to have distorted loops and tails, grown under the influence of disruptive gravitational tides. But the predominantly bluish galaxy, NGC 7320, is closer, just 40 million light-years...
  • Astronomy Picture of the Day -- Aurigae Nebulae

    02/24/2012 3:52:39 AM PST · by SunkenCiv · 18 replies · 1+ views
    NASA ^ | February 24, 2012 | (see photo credit)
    Explanation: Rich in star clusters and nebulae, the ancient constellation of Auriga, the Charioteer, rides high in northern winter night skies. Composed from narrow and broadband filter data and spanning nearly 8 Full Moons (4 degrees) on the sky, this deep telescopic view recorded in January shows off some of Auriga's celestial bounty. The field includes emission region IC 405 (top left) about 1,500 light-years distant. Also known as the Flaming Star Nebula, its red, convoluted clouds of glowing hydrogen gas are energized by hot O-type star AE Aurigae. IC 410 (top right) is significantly more distant, some 12,000 light-years...
  • Astronomy Picture of the Day -- A Zodiacal Skyscape

    02/23/2012 4:34:18 AM PST · by SunkenCiv · 4 replies
    NASA ^ | February 23, 2012 | (see photo credit)
    Explanation: Venus and Jupiter are this month's two brightest planets. Shortly after sunset on February 20, they dominate the sky above the western horizon and this snowy landscape. In clear and transparent skies over Cherry Springs State Park, Pennsylvania, USA, they are also seen immersed in Zodiacal light. The extended, diffuse, triangular glow is sunlight scattered by dust along the plane of the ecliptic. Brighter near the horizon, the Zodiacal glow angles upward, first to Venus and then to Jupiter hugging the ecliptic as they orbit the Sun. Fading even further, the glow stretches toward the lovely Pleides star cluster...
  • Astronomy Picture of the Day -- A Sailing Stone in Death Valley

    02/21/2012 9:54:30 PM PST · by SunkenCiv · 32 replies · 3+ views
    NASA ^ | February 22, 2012 | (see photo credit)
    Explanation: How did this big rock end up on this strange terrain? One of the more unusual places here on Earth occurs inside Death Valley, California, USA. There a dried lakebed named Racetrack Playa exists that is almost perfectly flat, with the odd exception of some very large stones, one of which is pictured above. Now the flatness and texture of large playa like Racetrack are fascinating but not scientifically puzzling -- they are caused by mud flowing, drying, and cracking after a heavy rain. Only recently, however, has a viable scientific hypothesis been given to explain how 300-kilogram sailing...
  • Astronomy Picture of the Day -- Anticrepuscular Rays Over Wyoming

    02/21/2012 9:06:41 PM PST · by SunkenCiv · 8 replies
    NASA ^ | February 21, 2012 | (see photo credit)
    Explanation: What's happening over the horizon? Although the scene may appear somehow supernatural, nothing more unusual is occurring than a setting Sun and some well placed clouds. Pictured above are anticrepuscular rays. To understand them, start by picturing common crepuscular rays that are seen any time that sunlight pours though scattered clouds. Now although sunlight indeed travels along straight lines, the projections of these lines onto the spherical sky are great circles. Therefore, the crepuscular rays from a setting (or rising) sun will appear to re-converge on the other side of the sky. At the anti-solar point 180 degrees around...
  • Astronomy Picture of the Day -- Barred Spiral Galaxy NGC 1073

    02/20/2012 7:51:38 AM PST · by SunkenCiv · 8 replies · 2+ views
    NASA ^ | February 20, 2012 | (see photo credit)
    Explanation: Many spiral galaxies have bars across their centers. Even our own Milky Way Galaxy is thought to have a modest central bar. Prominently barred spiral galaxy NGC 1073, pictured above, was captured in spectacular detail in this recently released image taken by the orbiting Hubble Space Telescope. Visible are dark filamentary dust lanes, young clusters of bright blue stars, red emission nebulas of glowing hydrogen gas, a long bright bar of stars across the center, and a bright active nucleus that likely houses a supermassive black hole. Light takes about 55 million years to reach us from NGC 1073,...
  • Astronomy Picture of the Day -- A Message From Earth

    02/19/2012 8:50:24 AM PST · by SunkenCiv · 16 replies · 1+ views
    NASA ^ | February 19, 2012 | (see photo credit)
    Explanation: What are these Earthlings trying to tell us? The above message was broadcast from Earth towards the globular star cluster M13 in 1974. During the dedication of the Arecibo Observatory - still the largest single radio telescope in the world - a string of 1's and 0's representing the above diagram was sent. This attempt at extraterrestrial communication was mostly ceremonial - humanity regularly broadcasts radio and television signals out into space accidentally. Even were this message received, M13 is so far away we would have to wait almost 50,000 years to hear an answer. The above message gives...
  • Astronomy Picture of the Day -- On the Road to Carina

    02/18/2012 7:31:51 AM PST · by SunkenCiv · 11 replies · 1+ views
    NASA ^ | February 18, 2012 | (see photo credit)
    Explanation: This rugged road through the dark Atacama Desert seems to lead skyward toward the bright stars and glowing nebulae of the southern Milky Way. If you follow the road you will get to Cerro Armazones peak in Chile, future construction site for the 40-meter class European Extremely Large Telescope. For now though, sliding your cursor across the image will identify wonders of the southern skies in view. The scene is dominated by the reddish glow of the Great Carina Nebula, one of our galaxy's largest star forming regions. In fact, the remarkable skyscape is not a composite of varying...
  • Astronomy Picture of the Day -- At the West Wall of Aristarchus Crater

    02/17/2012 2:53:26 AM PST · by SunkenCiv · 13 replies
    NASA ^ | February 17, 2012 | (see photo credit)
    Explanation: Aristarchus Plateau is anchored in the vast lava flows of the Moon's Oceanus Procellarum. At the plateau's southeastern edge lies the spectacular Aristarchus Crater, an impact crater 40 kilometers wide and 3 kilometers deep. Scan along this remarkable panorama and you will find yourself gazing directly at the crater's west wall for some 25 kilometers. Features along the terraced wall include dark impact melt and debris deposits, bright excavated material, and boulders over 100 meters wide. At a full resolution of 1.6 meters per pixel, the sharp mosaic was created from images recorded by the Lunar Reconnaissance Orbiter's narrow...
  • Astronomy Picture of the Day -- NGC 5965 and NGC 5963 in Draco

    02/16/2012 3:33:03 AM PST · by SunkenCiv · 16 replies
    NASA ^ | February 16, 2012 | (see photo credit)
    Explanation: These two spiral galaxies make a photogenic pair, found within the boundaries of the northern constellation Draco. Contrasting in color and orientation, NGC 5965 is nearly edge-on to our line of sight and dominated by yellow hues, while bluish NGC 5963 is closer to face-on. Of course, even in this well-framed cosmic snapshot the scene is invaded by other galaxies, including small elliptical NGC 5969 at the lower left. Brighter, spiky stars in our own Milky Way are scattered through the foreground. Though they seem to be close and of similar size, galaxies NGC 5965 and NGC 5963 are...
  • Astronomy Picture of the Day -- Merope's Reflection Nebula

    02/15/2012 3:49:22 AM PST · by SunkenCiv · 6 replies
    NASA ^ | February 15, 2012 | (see photo credit)
    Explanation: Reflection nebulas reflect light from a nearby star. Many small carbon grains in the nebula reflect the light. The blue color typical of reflection nebula is caused by blue light being more efficiently scattered by the carbon dust than red light. The brightness of the nebula is determined by the size and density of the reflecting grains, and by the color and brightness of the neighboring star(s). NGC 1435, pictured above, surrounds Merope (23 Tau), one of the brightest stars in the Pleiades (M45). The Pleiades nebulosity is caused by a chance encounter between an open cluster of stars...
  • Astronomy Picture of the Day -- The Rosette Nebula

    02/14/2012 7:24:39 PM PST · by SunkenCiv · 10 replies
    NASA ^ | February 14, 2012 | (see photo credit)
    Explanation: The Rosette Nebula is not the only cosmic cloud of gas and dust to evoke the imagery of flowers -- but it is the most famous. At the edge of a large molecular cloud in Monoceros, some 5,000 light years away, the petals of this rose are actually a stellar nursery whose lovely, symmetric shape is sculpted by the winds and radiation from its central cluster of hot young stars. The stars in the energetic cluster, cataloged as NGC 2244, are only a few million years old, while the central cavity in the Rosette Nebula, cataloged as NGC 2237,...
  • Astronomy Picture of the Day -- An Unusual Venusian Oval

    02/13/2012 6:26:16 PM PST · by SunkenCiv · 12 replies
    NASA ^ | February 13, 2012 | (see photo credit)
    Explanation: Why would Venus appear oval? Venus has been seen countless times from the surface of the Earth, and every time the Earth's atmosphere has dispersed its light to some degree. When the air has just the right amount of dust or water droplets, small but distant objects like Venus appear spread out into an angularly large aureole. Aureoles are not unusual to see and are frequently noted as circular coronas around the Sun or Moon. Recently, however, aureoles have been imaged that are not circular but distinctly oval. The above oval Venusian aureole was imaged by the astrophotographer who...
  • Astronomy Picture of the Day -- Orion in Gas, Dust, and Stars

    02/12/2012 7:04:54 AM PST · by SunkenCiv · 11 replies
    NASA ^ | February 12, 2012 | (see photo credit)
    Explanation: The constellation of Orion holds much more than three stars in a row. A deep exposure shows everything from dark nebula to star clusters, all embedded in an extended patch of gaseous wisps in the greater Orion Molecular Cloud Complex. The brightest three stars on the far left are indeed the famous three stars that make up the belt of Orion. Just below Alnitak, the lowest of the three belt stars, is the Flame Nebula, glowing with excited hydrogen gas and immersed in filaments of dark brown dust. Below the frame center and just to the right of Alnitak...
  • Astronomy Picture of the Day -- At the Core of NGC 6752

    02/11/2012 5:47:48 PM PST · by SunkenCiv · 23 replies
    NASA ^ | February 10, 2012 | (see photo credit)
    Explanation: This sharp Hubble Space Telescope view looks deep into NGC 6752. Some 13,000 light-years away toward the southern constellation Pavo, the globular star cluster roams the halo of our Milky Way galaxy. Over 10 billion years old, NGC 6752 holds over 100 thousand stars in a sphere about 100 light-years in diameter, but the Hubble image frame spans the central 10 or so light-years and resolves stars near the dense cluster core. In fact the frame includes some of the cluster's blue straggler stars, stars which appear to be too young and massive to exist in a cluster whose...
  • Astronomy Picture of the Day -- A February Moon's Halo

    02/11/2012 5:47:51 PM PST · by SunkenCiv · 10 replies
    NASA ^ | February 11, 2012 | (see photo credit)
    Explanation: Lighting the night last Tuesday, February's Full Moon is sometimes called the Snow Moon. But the Moon was not quite full in this mosaicked skyscape recorded on February 2 south of Budapest, Hungary, and there was no snow either. Still, thin clouds of ice crystals hung in the cold, wintry sky creating this gorgeous lunar halo. Refraction of moonlight by the six-sided crystals produce the slightly colored halo with its characteristic radius of 22 degrees. Just below the Moon is bright star Aldebaran. Also well within the halo at the right is the Pleiades star cluster. At the lower...
  • Astronomy Picture of the Day -- Trees, Stars, Aurora!

    02/08/2012 9:26:49 PM PST · by SunkenCiv · 12 replies
    NASA ^ | February 09, 2012 | (see photo credit)
    Explanation: Have you ever seen an aurora? Auroras are occurring again with increasing frequency. With the Sun being unusually dormant over the past four years, the amount of Sun-induced auroras has been unusually low. More recently, however, our Sun has become increasingly active and exhibiting a greater abundance of sunspots, flares, and coronal mass ejections. Solar activity like this typically expels charged particles into the Solar System, some of which may trigger Earthly auroras. Two weeks ago, beyond trees and before stars, a solar storm precipitated the above timelapse displays of picturesque auroras above Ravnastua, Skoganvarre and Lakselv, Norway. Curtains...
  • Astronomy Picture of the Day -- Enceladus Backlit by Saturn

    02/08/2012 4:28:02 AM PST · by SunkenCiv · 10 replies
    NASA ^ | February 08, 2012 | (see photo credit)
    Explanation: This moon is shining by the light of its planet. Specifically, a large portion of Enceladus pictured above is illuminated primarily by sunlight first reflected from the planet Saturn. The result is that the normally snow-white moon appears in the gold color of Saturn's cloud tops. As most of the illumination comes from the image left, a labyrinth of ridges throws notable shadows just to the right of the image center, while the kilometer-deep canyon Labtayt Sulci is visible just below. The bright thin crescent on the far right is the only part of Enceladus directly lit by the...
  • Astronomy Picture of the Day -- The Belt of Venus Over Mercedes, Argentina

    02/07/2012 4:22:45 AM PST · by SunkenCiv · 15 replies
    NASA ^ | February 07, 2012 | (see photo credit)
    Although you've surely seen it, you might not have noticed it. During a cloudless twilight, just before sunrise or after sunset, part of the atmosphere above the horizon appears slightly off-color, slightly pink or orange. Called the Belt of Venus, this off-color band between the dark eclipsed sky and the blue sky can be seen in nearly every direction including that opposite the Sun. Straight above, blue sky is normal sunlight reflecting off the atmosphere. In the Belt of Venus, however, the atmosphere reflects light from the setting (or rising) Sun which appears more red. Below the Belt of Venus,...
  • Astronomy Picture of the Day -- Dust of the Orion Nebula

    02/06/2012 4:26:18 AM PST · by SunkenCiv · 6 replies
    NASA ^ | February 06, 2012 | (see photo credit)
    Explanation: What surrounds a hotbed of star formation? In the case of the Orion Nebula -- dust. The entire Orion field, located about 1600 light years away, is inundated with intricate and picturesque filaments of dust. Opaque to visible light, dust is created in the outer atmosphere of massive cool stars and expelled by a strong outer wind of particles. The Trapezium and other forming star clusters are embedded in the nebula. The intricate filaments of dust surrounding M42 and M43 appear brown in the above image, while central glowing gas is highlighted in red. Over the next few million...
  • Astronomy Picture of the Day -- Lunation

    02/05/2012 8:57:07 AM PST · by SunkenCiv · 30 replies
    NASA ^ | February 05, 2012 | (see photo credit)
    Explanation: Our Moon's appearance changes nightly. This time-lapse sequence shows what our Moon looks like during a lunation, a complete lunar cycle. As the Moon orbits the Earth, the half illuminated by the Sun first becomes increasingly visible, then decreasingly visible. The Moon always keeps the same face toward the Earth. The Moon's apparent size changes slightly, though, and a slight wobble called a libration is discernible as it progresses along its elliptical orbit. During the cycle, sunlight reflects from the Moon at different angles, and so illuminates different features differently. A full lunation takes about 29.5 days, just under...
  • Astronomy Picture of the Day -- Comet Garradd and M92

    02/04/2012 6:35:20 AM PST · by SunkenCiv · 5 replies
    NASA ^ | February 04, 2012 | (see photo credit)
    Explanation: Sweeping slowly through the constellation Hercules, Comet Garradd (C2009/P1) passed with about 0.5 degrees of globular star cluster M92 on February 3. Captured here in its latest Messier moment, the steady performer remains just below naked-eye visibility with a central coma comparable in brightness to the dense, well-known star cluster. The rich telescopic view from New Mexico's, early morning skies, also features Garradd's broad fan shaped dust tail and a much narrower ion tail that extends up and beyond the right edge of the frame. Pushed out by the pressure of sunlight, the dust tail tends to trail the...
  • Astronomy Picture of the Day -- Inside the Eagle Nebula

    02/04/2012 5:56:20 AM PST · by SunkenCiv · 13 replies
    NASA ^ | February 03, 2012 | (see photo credit)
    Explanation: In 1995, a now famous picture from the Hubble Space Telescope featured Pillars of Creation, star forming columns of cold gas and dust light-years long inside M16, the Eagle Nebula. This remarkable false-color composite image revisits the nearby stellar nursery with image data from the orbiting Herschel Space Observatory and XMM-Newton telescopes. Herschel's far infrared detectors record the emission from the region's cold dust directly, including the famous pillars and other structures near the center of the scene. Toward the other extreme of the electromagnetic spectrum, XMM-Newton's X-ray vision reveals the massive, hot stars of the nebula's embedded star...
  • Astronomy Picture of the Day -- La Silla Star Trails North and South

    02/02/2012 6:00:24 PM PST · by SunkenCiv · 4 replies
    NASA ^ | February 02, 2012 | (see photo credit)
    Explanation: Fix your camera to a tripod and you can record graceful trails traced by the stars as planet Earth rotates on its axis. If the tripod is set up at ESO's La Silla Observatory, high in the Atacama desert of Chile, your star trails would look something like this. Spanning about 4 hours on the night of January 24, the image is actually a composite of 250 consecutive 1-minute exposures, looking toward the north. The North Celestial Pole, at the center of the star trail arcs, is just below the horizon in this southern hemisphere perspective. In the foreground,...
  • Astronomy Picture of the Day -- Red Aurora Over Australia

    02/01/2012 8:24:04 PM PST · by SunkenCiv · 17 replies · 1+ views
    NASA ^ | February 01, 2012 | (see photo credit)
    Explanation: Why would the sky glow red? Aurora. Last week's solar storms, emanating mostly from active sunspot region 1402, showered particles on the Earth that excited oxygen atoms high in the Earth's atmosphere. As the excited element's electrons fell back to their ground state, they emitted a red glow. Were oxygen atoms lower in Earth's atmosphere excited, the glow would be predominantly green. Pictured above, this high red aurora is visible just above the horizon last week near Flinders, Victoria, Australia. The sky that night, however, also glowed with more familiar but more distant objects, including the central disk of...
  • Astronomy Picture of the Day -- The Helix Nebula from the VISTA Telescope

    01/31/2012 7:06:50 PM PST · by SunkenCiv · 10 replies
    NASA ^ | January 31, 2012 | (see photo credit)
    Explanation: Will our Sun look like this one day? The Helix Nebula is one of brightest and closest examples of a planetary nebula, a gas cloud created at the end of the life of a Sun-like star. The outer gasses of the star expelled into space appear from our vantage point as if we are looking down a helix. The remnant central stellar core, destined to become a white dwarf star, glows in light so energetic it causes the previously expelled gas to fluoresce. The Helix Nebula, given a technical designation of NGC 7293, lies about 700 light-years away towards...
  • Astronomy Picture of the Day -- Blue Marble Earth from Suomi NPP

    01/30/2012 4:08:28 AM PST · by SunkenCiv · 9 replies
    NASA ^ | January 30, 2012 | (see photo credit)
    Explanation: Behold one of the more detailed images of the Earth yet created. This Blue Marble Earth montage shown above -- created from photographs taken by the Visible/Infrared Imager Radiometer Suite (VIIRS) instrument on board the new Suomi NPP satellite -- shows many stunning details of our home planet. The Suomi NPP satellite was launched last October and renamed last week after Verner Suomi, commonly deemed the father of satellite meteorology. The composite was created from the data collected during four orbits of the robotic satellite taken earlier this month and digitally projected onto the globe. Many features of North...
  • Astronomy Picture of the Day -- Blue Marble Earth from Suomi NPP

    01/30/2012 4:08:06 AM PST · by SunkenCiv · 2 replies
    NASA ^ | January 30, 2012 | (see photo credit)
    Explanation: Behold one of the more detailed images of the Earth yet created. This Blue Marble Earth montage shown above -- created from photographs taken by the Visible/Infrared Imager Radiometer Suite (VIIRS) instrument on board the new Suomi NPP satellite -- shows many stunning details of our home planet. The Suomi NPP satellite was launched last October and renamed last week after Verner Suomi, commonly deemed the father of satellite meteorology. The composite was created from the data collected during four orbits of the robotic satellite taken earlier this month and digitally projected onto the globe. Many features of North...
  • Astronomy Picture of the Day -- Molecular Cloud Barnard 68

    01/29/2012 9:56:22 AM PST · by SunkenCiv · 12 replies
    NASA ^ | January 29, 2012 | (see photo credit)
    Explanation: Where did all the stars go? What used to be considered a hole in the sky is now known to astronomers as a dark molecular cloud. Here, a high concentration of dust and molecular gas absorb practically all the visible light emitted from background stars. The eerily dark surroundings help make the interiors of molecular clouds some of the coldest and most isolated places in the universe. One of the most notable of these dark absorption nebulae is a cloud toward the constellation Ophiuchus known as Barnard 68, pictured above. That no stars are visible in the center indicates...
  • Astronomy Picture of the Day -- Planet Aurora Borealis

    01/28/2012 8:49:34 AM PST · by SunkenCiv · 7 replies
    NASA ^ | January 28, 2012 | (see photo credit)
    Explanation: Illuminated by an eerie greenish light, this remarkable little planet is covered with ice and snow and ringed by tall pine trees. Of course, this little planet is actually planet Earth, and the surrounding stars are above the horizon near Östersund, Sweden. The pale greenish illumination is from a curtain of shimmering Aurora Borealis also known as the Northern Lights. The display was triggered when a giant solar coronal mass ejection (CME) rocked planet Earth's magnetosphere on January 24th and produced a strong geomagnetic storm. Northern hemisphere skygazers will also recognize the familiar orientation of stars at the left,...
  • Astronomy Picture of the Day -- NGC 3239 and SN 2012A

    01/28/2012 8:43:54 AM PST · by SunkenCiv · 2 replies
    NASA ^ | January 27, 2012 | (see photo credit)
    Explanation: About 40,000 light-years across, pretty, irregular galaxy NGC 3239 lies near the center of this lovely field of galaxies in the galaxy rich constellation Leo. At a distance of only 25 million light-years it dominates the frame, sporting a peculiar arrangement of structures, young blue star clusters and star forming regions, suggesting that NGC 3239 (aka Arp 263) is the result of a galaxy merger. Appearing nearly on top of the pretty galaxy is a bright, spiky, foreground star, a nearby member of our own Milky Way galaxy almost directly along our line-of-sight to NGC 3239. Still, NGC 3239...
  • Astronomy Picture of the Day -- NGC 4449: Star Stream for a Dwarf Galaxy

    01/26/2012 4:31:42 AM PST · by SunkenCiv · 10 replies
    NASA ^ | January 25, 2012 | (see photo credit)
    Explanation: A mere 12.5 million light-years from Earth, irregular dwarf galaxy NGC 4449 lies within the confines of Canes Venatici, the constellation of the Hunting Dogs. About the size of our Milky Way's satellite galaxy the Large Magellanic Cloud, NGC 4449 is undergoing an intense episode of star formation, evidenced by its wealth of young blue star clusters, pinkish star forming regions, and obscuring dust clouds in this deep color portrait. It's also holds the distinction of being the first dwarf galaxy with an identified tidal star stream, faintly seen at the lower right. Placing your cursor over the image...
  • Astronomy Picture of the Day -- Opportunity Rover Spots Greeley Haven on Mars

    01/25/2012 4:20:45 AM PST · by SunkenCiv · 12 replies
    NASA ^ | January 25, 2012 | (see photo credit)
    Explanation: Where on Mars should you spend the winter? As winter approached in the southern hemisphere of Mars last November, the Opportunity rover had just this problem -- it needed a place to go. The reduced amount of sunlight impacting Opportunity's solar panels combined with the extra power needed to keep equipment warm could drain Opportunity's batteries. Therefore Opportunity was instructed to climb onto the 15 degree incline of Greeley's Haven, shown as the rocky slope ahead. The incline increased power input as Opportunity's solar panels now have greater exposure to sunlight, while also giving the rolling robot some interesting...
  • Astronomy Picture of the Day -- January Aurora Over Norway

    01/24/2012 6:45:23 PM PST · by SunkenCiv · 10 replies
    NASA ^ | January 24, 2012 | (see photo credit)
    Explanation: What's that in the sky? An aurora. A large coronal mass ejection occurred on our Sun five days ago, throwing a cloud of fast moving electrons, protons, and ions toward the Earth. Although most of this cloud passed above the Earth, some of it impacted our Earth's magnetosphere and resulted in spectacular auroras being seen at high northern latitudes. Pictured above is a particularly photogenic auroral corona captured last night above Grotfjord, Norway. To some, this shimmering green glow of recombining atmospheric oxygen might appear as a large eagle, but feel free to share what it looks like to...
  • Astronomy Picture of the Day -- Deep Orion Over the Canary Islands

    01/24/2012 6:38:39 PM PST · by SunkenCiv · 10 replies
    NASA ^ | January 23, 2012 | (see photo credit)
    Explanation: Which attracts your eye more -- the sky or the ground? On the ground are rocky peaks in Teide National Park on Tenerife Island of the Spanish Canary Islands off the northwestern coast of Africa. The volcanic landscape features old island summits and is sometimes used as a testbed for instruments on future Martian rovers. The lights of a nearby hotel shine on the far left. Storm clouds are visible on the horizon, artificially strutted from multiple exposures. Dividing the sky, across the middle of the above deep image, is the vertical band of the Milky Way Galaxy. The...
  • Astronomy Picture of the Day -- Saturn's Hexagon Comes to Light

    01/21/2012 11:50:53 PM PST · by SunkenCiv · 30 replies · 1+ views
    NASA ^ | January 22, 2012 | (see photo credit)
    Explanation: Believe it or not, this is the North Pole of Saturn. It is unclear how an unusual hexagonal cloud system that surrounds Saturn's north pole was created, keeps its shape, or how long it will last. Originally discovered during the Voyager flybys of Saturn in the 1980s, nobody has ever seen anything like it elsewhere in the Solar System. Although its infrared glow was visible previously to the Cassini spacecraft now orbiting Saturn, in 2009 the mysterious hexagonal vortex became fully illuminated by sunlight for the first time during the Cassini's visit. Since then, Cassini has imaged the rotating...