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Astronomy Picture of the Day (General/Chat)

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  • Astronomy Picture of the Day -- The Wolf's Moon

    01/20/2012 3:39:49 AM PST · by SunkenCiv · 9 replies · 1+ views
    NASA ^ | January 20, 2012 | (see photo credit)
    Explanation: A Full Moon rising can be a dramatic celestial sight, and Full Moons can have many names. Captured on January 8 from Ötersund, Sweden, this evocative moonrise portrait might make you feel the cold of winter in the north. If you can also imagine wolves howling in the distance then you probably understand why Native Americans would have called it the Wolf Moon, their traditional name for the first Full Moon in January. The photographer reports that no wolves were heard though, as he watched this beautiful Full Moon rise in fading light over the eastern horizon, echoing the...
  • Astronomy Picture of the Day -- The Hunter's Stars

    01/19/2012 5:16:02 PM PST · by SunkenCiv · 17 replies
    NASA ^ | January 19, 2012 | (see photo credit)
    Explanation: Begirt with many a blazing star, Orion, the Hunter, is one of the most easily recognizable constellations. In this night skyscape from January 15, the hunter's stars rise in the northern hemisphere's winter sky, framed by bare trees and bounded below by terrestrial lights around Lough Eske (Lake of Fish) in County Donegal, Ireland. Red giant star Betelgeuse is striking in yellowish hues at Orion's shoulder above and left of center. Rivaling the bright red giant, Rigel, a blue supergiant star holds the opposing position near Orion's foot. Of course, the sword of Orion hangs from the hunter's three...
  • Astronomy Picture of the Day -- Cygnus-X: The Inner Workings of a Nearby Star Factory

    01/18/2012 4:19:10 AM PST · by SunkenCiv · 10 replies
    NASA ^ | January 18, 2012 | (see photo credit)
    Explanation: How do stars form? To help study this complex issue, astronomers took a deep infrared image of Cygnus X, the largest known star forming region in the entire Milky Way Galaxy. The above recently-released image was taken in 2009 by the orbiting Spitzer Space Telescope and digitally translated into colors humans can see, with the hottest regions colored the most blue. Visible are large bubbles of hot gas inflated by the winds of massive stars soon after they form. Current models posit that these expanding bubbles sweep up gas and sometimes even collide, frequently creating regions dense enough to...
  • Astronomy Picture of the Day -- IC 2118: The Witch Head Nebula

    01/16/2012 9:18:55 PM PST · by SunkenCiv · 37 replies
    NASA ^ | January 17, 2012 | (see photo credit)
    Explanation: Double, double toil and trouble; Fire burn, and cauldron bubble -- maybe Macbeth should have consulted the Witch Head Nebula. This suggestively shaped reflection nebula is associated with the bright star Rigel in the constellation Orion. More formally known as IC 2118, the Witch Head Nebula glows primarily by light reflected from bright star Rigel, located just below the lower edge of the above image. Fine dust in the nebula reflects the light. The blue color is caused not only by Rigel's blue color but because the dust grains reflect blue light more efficiently than red. The same physical...
  • Astronomy Picture of the Day -- Zodiacal Light and the False Dawn

    01/16/2012 10:37:38 AM PST · by SunkenCiv · 9 replies
    NASA ^ | January 16, 2012 | (see photo credit)
    Explanation: Is it dawn or false dawn? During certain times of the year, the horizon near the rising Sun will begin to glow unusually early. This early glow does not originate directly from the Sun, but rather from sunlight reflected by interplanetary dust. Called zodiacal light, the glowing triangle of light may be mistaken, for a while, for a sunrise, and so may be called a false dawn. Pictured above, two false dawns were recorded in time lapse movies each spanning about five hours from the perch of the highest observatory in the world: Mount Saraswati near Hanle, India. At...
  • Astronomy Picture of the Day -- Infrared Portrait of the Large Magellanic Cloud

    01/15/2012 3:50:08 PM PST · by SunkenCiv · 16 replies
    NASA ^ | January 15, 2012 | (see photo credit)
    Explanation: Cosmic dust clouds ripple across this infrared portrait of our Milky Way's satellite galaxy, the Large Magellanic Cloud. In fact, the remarkable composite image from the Herschel Space Observatory and the Spitzer Space Telescope show that dust clouds fill this neighboring dwarf galaxy, much like dust along the plane of the Milky Way itself. The dust temperatures tend to trace star forming activity. Spitzer data in blue hues indicate warm dust heated by young stars. Herschel's instruments contributed the image data shown in red and green, revealing dust emission from cooler and intermediate regions where star formation is just...
  • Astronomy Picture of the Day -- NGC 6369: The Little Ghost Nebula

    01/13/2012 9:23:04 PM PST · by SunkenCiv · 6 replies · 1+ views
    NASA ^ | January 14, 2012 | (see photo credit)
    Explanation: This pretty planetary nebula, cataloged as NGC 6369, was discovered by 18th century astronomer William Herschel as he used a telescope to explore the medicinal constellation Ophiucus. Round and planet-shaped, the nebula is also relatively faint and has acquired the popular moniker of Little Ghost Nebula. Planetary nebulae in general are not at all related to planets, but instead are created at the end of a sun-like star's life as its outer layers expand into space while the star's core shrinks to become a white dwarf. The transformed white dwarf star, seen near the center, radiates strongly at ultraviolet...
  • Astronomy Picture of the Day -- Saturn's Iapetus: Painted Moon

    01/13/2012 5:55:13 PM PST · by SunkenCiv · 18 replies · 1+ views
    NASA ^ | January 13, 2012 | (see photo credit)
    Explanation: What has happened to Saturn's moon Iapetus? Vast sections of this strange world are dark as coal, while others are as bright as ice. The composition of the dark material is unknown, but infrared spectra indicate that it possibly contains some dark form of carbon. Iapetus also has an unusual equatorial ridge that makes it appear like a walnut. To help better understand this seemingly painted moon, NASA directed the robotic Cassini spacecraft orbiting Saturn to swoop within 2,000 kilometers in 2007. Pictured above, from about 75,000 kilometers out, Cassini's trajectory allowed unprecedented imaging of the hemisphere of Iapetus...
  • Astronomy Picture of the Day -- The Case of the Missing Supernova Companion

    01/11/2012 9:39:24 PM PST · by SunkenCiv · 9 replies
    NASA ^ | January 12, 2012 | (see photo credit)
    Explanation: Where's the other star? At the center of this supernova remnant should be the companion star to the star that blew up. Identifying this star is important for understanding just how Type Ia supernova detonate, which in turn could lead to a better understanding of why the brightness of such explosions are so predictable, which in turn is key to calibrating the entire nature of our universe. The trouble is that even a careful inspection of the center of SNR 0509-67.5 has not found any star at all. This indicates that the companion is intrinsically very faint -- much...
  • Astronomy Picture of the Day -- Little Planet Lovejoy

    01/10/2012 9:47:55 PM PST · by SunkenCiv · 5 replies · 1+ views
    NASA ^ | January 11, 2012 | (see photo credit)
    Explanation: Once a bright apparition in the southern hemisphere dawn Comet Lovejoy is fading, but its long tail still stretches across skies near the south celestial pole. Captured on the morning of December 30th, the comet appears near edge of this little planet as well. Of course, the little planet is actually planet Earth and the image was created from a 12 frame mosaic used to construct a spherical panorama. The type of stereographic projection used to map the image pixels is centered directly below the camera and is known as the little planet projection. Stars surrounding this little planet...
  • Astronomy Picture of the Day -- Vesta Rocks

    01/10/2012 6:13:14 PM PST · by SunkenCiv · 11 replies · 1+ views
    NASA ^ | December 10, 2011 | (see photo credit)
    Explanation: These colorful images are of thin slices of meteorites viewed through a polarizing microscope. Part of the group classified as HED (Howardite, Eucrite, Diogenite) meteorites for their mineral content, they likely fell to Earth from 4 Vesta, the mainbelt asteroid currently being explored by NASA's Dawn spacecraft. Why are they thought to be from Vesta? Because the HED meteorites have visible and infrared spectra that match the spectrum of that small world. The hypothesis of their origin on Vesta is also consistent with data from Dawn's ongoing observations. Excavated by impacts, the diogenites shown here would have originated deep...
  • Astronomy Picture of the Day -- Bright Star Regulus near the Leo I Dwarf Galaxy

    01/09/2012 9:23:36 PM PST · by SunkenCiv · 9 replies · 1+ views
    NASA ^ | January 09, 2012 | (see photo credit)
    Explanation: The star near the top is so bright that it is sometimes hard to notice the galaxy toward the bottom. Pictured above, both the star, Regulus, and the galaxy, Leo I, can be found within one degree of each other toward the constellation of the Lion (Leo). Regulus is part of a multiple star system, with a close companion double star visible to the lower left of the young main sequence star. Leo I is a dwarf spheroidal galaxy in the Local Group of galaxies dominated by our Milky Way Galaxy and M31. Leo I is thought to be...
  • Astronomy Picture of the Day -- Facing NGC 6946

    01/09/2012 7:01:52 PM PST · by SunkenCiv · 13 replies · 1+ views
    NASA ^ | January 09, 2012 | (see photo credit)
    Explanation: From our vantage point in the Milky Way Galaxy, we see NGC 6946 face-on. The big, beautiful spiral galaxy is located just 10 million light-years away, behind a veil of foreground dust and stars in the high and far-off constellation of Cepheus. From the core outward, the galaxy's colors change from the yellowish light of old stars in the center to young blue star clusters and reddish star forming regions along the loose, fragmented spiral arms. NGC 6946 is also bright in infrared light and rich in gas and dust, exhibiting a high star birth and death rate. In...
  • Astronomy Picture of the Day -- Lighthouse and Meteor

    01/08/2012 5:56:01 PM PST · by SunkenCiv · 7 replies
    NASA ^ | January 08, 2012 | (see photo credit)
    Explanation: Named for a forgotten constellation, the Quadrantid Meteor Shower is an annual event for planet Earth's northern hemisphere skygazers. It usually peaks briefly in the cold, early morning hours of January 4. The shower's radiant point on the sky lies within the old, astronomically obsolete constellation Quadrans Muralis. That position is situated near the boundaries of the modern constellations Hercules, Bootes, and Draco. Many of this year's Quadrantid meteors were dim, but the one captured in this north-looking view is bright and easy to spot. In the foreground is the Maurice River's East Point Lighthouse located near the southern...
  • Astronomy Picture of the Day -- Grand Spiral Galaxy NGC 1232

    01/07/2012 2:17:12 PM PST · by SunkenCiv · 18 replies · 1+ views
    NASA ^ | January 07, 2012 | (see photo credit)
    Explanation: 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...
  • Astronomy Picture of the Day -- A Wide Field Image of the Galactic Center

    01/06/2012 2:27:26 PM PST · by SunkenCiv · 15 replies
    NASA ^ | January 06, 2012 | (see photo credit)
    Explanation: From Sagittarius to Scorpius, the central Milky Way is a truly beautiful part of planet Earth's night sky. The gorgeous region is captured in this wide field image spanning about 30 degrees. The impressive cosmic vista, taken in 2010, shows off intricate dust lanes, bright nebulae, and star clusters scattered through our galaxy's rich central starfields. Starting on the left, look for the Lagoon and Trifid nebulae, the Cat's Paw, while on the right lies the Pipe dark nebula, and the colorful clouds of Rho Ophiuchi and Antares (right). The actual center of our Galaxy lies about 26,000 light...
  • Astronomy Picture of the Day -- Ringside with Titan and Dione

    01/05/2012 6:45:53 PM PST · by SunkenCiv · 20 replies
    NASA ^ | January 05, 2012 | (see photo credit)
    Explanation: Orbiting in the plane of Saturn's rings, Saturnian moons have a perpetual ringside view of the gorgeous gas giant planet. Of course, while passing near the ring plane the Cassini spacecraft also shares their stunning perspective. The rings themselves can be seen slicing across the middle of this Cassini snapshot from May of last year. The scene features Titan, largest, and Dione, third largest moon of Saturn. Remarkably thin, the bright rings still cast arcing shadows across the planet's cloud tops at the bottom of the frame. Pale Dione is about 1,100 kilometers across and orbits over 300,000 kilometers...
  • Astronomy Picture of the Day -- Starburst Galaxy IC 10

    01/04/2012 7:09:59 PM PST · by SunkenCiv · 30 replies
    NASA ^ | January 04, 2012 | (see photo credit)
    Explanation: Lurking behind dust and stars near the plane of our Milky Way Galaxy, IC 10 is a mere 2.3 million light-years distant. Even though its light is dimmed by intervening dust, the irregular dwarf galaxy still shows off vigorous star-forming regions that shine with a telltale reddish glow in this colorful skyscape. In fact, also a member of the Local Group of galaxies, IC 10 is the closest known starburst galaxy. Compared to other Local Group galaxies, IC 10 has a large population of newly formed stars that are massive and intrinsically very bright, including a luminous X-ray binary...
  • Astronomy Picture of the Day -- A Full Sky Aurora Over Norway

    01/02/2012 9:40:39 PM PST · by SunkenCiv · 24 replies
    NASA ^ | January 03, 2012 | (see photo credit)
    Explanation: Higher than the highest building, higher than the highest mountain, higher than the highest airplane, lies the realm of the aurora. Auroras rarely reach below 60 kilometers, and can range up to 1000 kilometers. Aurora light results from energetic electrons and protons striking molecules in the Earth's atmosphere. Frequently, when viewed from space, a complete aurora will appear as a circle around one of the Earth's magnetic poles. The above wide angle image, horizontally compressed, captured an unexpected auroral display that stretched across the sky one month ago over eastern Norway.
  • Astronomy Picture of the Day -- Spot the Moon

    01/01/2012 10:04:11 PM PST · by SunkenCiv · 14 replies
    NASA ^ | January 02, 2012 | (see photo credit)
    Explanation: Where's the full Moon? Somewhere in this image, the Earth's Moon is hiding. The entire Moon is visible, in its completely full phase, in plain sight. Even the photographer's keen eye couldn't find it even though he knew exactly where to look -- only the long exposure of his camera picked it up -- barely. Although by now you might be congratulating yourself on finding it, why was it so difficult to see? For one reason, this photograph was taken during the total lunar eclipse last month, when the Earth's shadow made the Moon much dimmer than a normal...