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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,...