Tag: NASA

Astronomy Picture of the Day

Astronomy Picture of the Day

Discover the cosmos!Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2011 September 29

Cocoon Nebula Wide Field
Image Credit & Copyright: Tony Hallas 

 

Explanation: In this crowded starfield spanning some 3 degrees within the high flying constellation Cygnus, the eye is drawn to the Cocoon Nebula. A compact star forming region, the cosmic Cocoon punctuates a long trail of obscuring interstellar dust clouds. Cataloged as IC 5146, the nebula is nearly 15 light-years wide, located some 4,000 light years away. Like other star forming regions, it stands out in red, glowing, hydrogen gas excited by the young, hot stars and blue, dust-reflected starlight at the edge of an otherwise invisible molecular cloud. In fact, the bright star near the center of this nebula is likely only a few hundred thousand years old, powering the nebular glow as it clears out a cavity in the molecular cloud’s star forming dust and gas. But the long dusty filaments that appear dark in this visible light image are themselves hiding stars in the process of formation, seen at infrared wavelengths.

Astronomy Picture of the Day for Sept. 28th – Violent Sunspot

Astronomy Picture of the Day

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2011 September 28

Violent Sunspot Group AR 1302 Unleashes a Flare
Image Credit: jp-Brahic

 

 Explanation: One of the most active sunspot groups in years is currently crossing the Sun. AR 1302 first came around the Sun’s edge last week and is so large it can be seen without a telescope. Coronal Mass Ejections from AR 1302 have already caused strong geomagnetic storms including notable aurora activity around both of Earth’s poles. Pictured above, plasma was left magnetically hanging above the Sun’s surface after AR 1302 emitted an X-class solar flare last Thursday. Earth is illustrated in the inset for a size comparison. Although another X-class flare was emitted on Saturday, no flares from AR 1302 have been aimed directly at the Earth, as yet. The AR 1302 sunspot group will continue to evolve but likely remain visible on the Sun for the next week.

Astronomy Picture of the Day for Sept. 27th – Not a Comet

Astronomy Picture of the Day

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M27: Not a Comet
Image Credit & Copyright: Martin Pugh  

 

Explanation: While hunting for comets in the skies above 18th century France, astronomer Charles Messier diligently kept a list of the things he encountered that were definitely not comets. This is number 27 on his now famous not-a-comet list. In fact, 21st century astronomers would identify it as a planetary nebula, but it’s not a planet either, even though it may appear round and planet-like in a small telescope. Messier 27 (M27) is an excellent example of a gaseous emission nebula created as a sun-like star runs out of nuclear fuel in its core. The nebula forms as the star’s outer layers are expelled into space, with a visible glow generated by atoms excited by the dying star’s intense but invisible ultraviolet light. Known by the popular name of the Dumbbell Nebula, the beautifully symmetric interstellar gas cloud is over 2.5 light-years across and about 1,200 light-years away in the constellation Vulpecula. This impressive color composite highlights details within the well-studied central region and fainter, seldom imaged features in the nebula’s outer halo. It incorporates broad and narrowband images recorded using filters sensitive to emission from sulfur, hydrogen and oxygen atoms.

 

 

Astronomy Picture of the Day for Sept. 26 – Dry Ice On Mars

Astronomy Picture of the Day

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2011 September 26

Dry Ice Pits on Mars
Image Credit: HiRISE, MRO, LPL (U. Arizona), NASA 

 

Explanation: Part of Mars is defrosting. Around the South Pole of Mars, toward the end of every Martian summer, the warm weather causes a section of the vast carbon-dioxide ice cap to evaporate. Pits begin to appear and expand where the carbon dioxide dry ice sublimates directly into gas. These ice sheet pits may appear to be lined with gold, but the precise composition of the dust that highlights the pit walls actually remains unknown. The circular depressions toward the image center measure about 60 meters across. The HiRISE camera aboard the Mars-orbiting Mars Reconnaissance Orbiter captured the above image in late July. In the next few months, as Mars continues its journey around the Sun, colder seasons will prevail, and the thin air will turn chilly enough not only to stop the defrosting but once again freeze out more layers of solid carbon dioxide.

NASA Image of the Day for September 23rd

Earth’s Moon

 

Photographed by the Expedition 28 crew aboard the International Space Station, this image shows the moon, the Earth’s only natural satellite, at center with the limb of Earth near the bottom transitioning into the orange-colored troposphere, the lowest and most dense portion of the Earth’s atmosphere. The troposphere ends abruptly at the tropopause, which appears in the image as the sharp boundary between the orange- and blue-colored atmosphere. The silvery-blue noctilucent clouds extend far above the Earth’s troposphere.

Image Credit: NASA

Astronomy Picture of the Day

Astronomy Picture of the Day

Discover the cosmos!Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 

2011 September 23

September’s Aurora
Image Credit & Copyright: Yuichi Takasaka / TWAN / www.blue-moon.ca 

 

Explanation: September’s equinox arrives today at 0905 UT. As the Sun crosses the celestial equator heading south, spring begins in the southern hemisphere and autumn in the north. And though the seasonal connection is still puzzling, both spring and autumn bring an increase in geomagnetic storms. So as northern nights grow longer, the equinox also heralds the arrival of a good season for viewing aurora. Recorded earlier this month, these curtains of September’s shimmering green light sprawl across a gorgeous night skyscape. In the foreground lies Hidden Lake Territorial Park near Yellowknife, Northwest Territories, Canada. Calm water reflects the aurora, with bright star trails peering through the mesmerizing sky glow. Of course, shining at altitudes of 100 kilometers or so, planet Earth’s auroras are visible from space.

*NEW* NASA Image of the Day for Sept. 20 – Sikorsky Helicopter

Sikorsky Helicopter

In this image taken in 1944, one of Langley Research Center’s Sikorsky YR-4B/HNS-1 helicopters is seen in the 30 x 60 Full Scale Tunnel. A technician sets up camera equipment for stop-action rotor-blade photos. The Sikorsky Company built hundreds of R-4 helicopters during World War II. It was the first mass-produced helicopter.

Image Credit: NASA

Astronomy Picture of the Day for Sept. 20 – Origin of Gold

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

On the Origin of Gold
Image Credit: Dana Berry, NASA

 

Explanation: Where did the gold in your jewelry originate? No one is completely sure. The relative average abundance in our Solar System appears higher than can be made in the early universe, in stars, and even in typical supernova explosions. Some astronomers have recently suggested that neutron-rich heavy elements such as gold might be most easily made in rare neutron-rich explosions such as the collision of neutron stars. Pictured above is an artist’s illustration depicting two neutron stars spiraling in toward each other, just before they collide. Since neutron star collisions are also suggested as the origin of short duration gamma-ray bursts, it is possible that you already own a souvenir from one of the most powerful explosions in the universe.

Astronomy Picture of the Day for Sept. 19th

Astronomy Picture of the Day

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2011 September 19

The South Pole of Asteroid Vesta
Image Credit: NASA, JPL-Caltech, UCLA, MPS, DLR, IDA 

 

Explanation: What created the circular structure around the south pole of asteroid Vesta? Pictured above, the bottom of the second largest object in the asteroid belt was recently imaged for the first time by the robotic Dawn satellite that arrived last month. A close inspection of the 260-meter resolution image shows not only hills and craters and cliffs and more craters, but ragged circular features that cover most of the lower right of the 500-kilometer sized object. Early speculation posits that the structure might have been created by a collision and coalescence with a smaller asteroid. Alternatively, the features might have originated in an internal process soon after the asteroid formed. New clues might come in the next few months as Dawn spirals down toward the rocky world and obtains images of increasingly high resolution.

Astronomy Picture of the Day for Sept. 18th –

Astronomy Picture of the Day

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2011 September 18

A Sharp View of the Sun
Credit: SST, Royal Swedish Academy of Sciences 

Explanation: Here is one of the sharper views of the Sun ever taken. This stunning image shows remarkable details of a dark sunspot across the image bottom and numerous boiling granules which appear like kernels of corn across the top. Taken in 2002, the picture was made using the Swedish Solar Telescope operating on the Canary Island of La Palma. The high resolution image was achieved using sophisticated adaptive optics, digital image stacking, and other processing techniques to counter the blurring effect of Earth’s atmosphere. Currently a sunspot group is crossing the Sun that is so large it can be easily seen by the cautious observer even without magnification.

Astronomy Picture of the Day for Sept. 17th

Astronomy Picture of the Day

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2011 September 17

Spitzer’s Orion
NASA, JPL-Caltech, T. Megeath (Univ. Toledo, Ohio) 

Explanation: Few cosmic vistas excite the imagination like the Orion Nebula, an immense stellar nursery some 1,500 light-years away. This stunning false-color view spans about 40 light-years across the region, constructed using infrared data from the Spitzer Space Telescope. Compared to its visual wavelength appearance, the brightest portion of the nebula is likewise centered on Orion’s young, massive, hot stars, known as the Trapezium Cluster. But the infrared image also detects the nebula’s many protostars, still in the process of formation, seen here in red hues. In fact, red spots along the dark dusty filament to the left of the bright cluster include the protostar cataloged as HOPS 68, recently found to have crystals of the silicate mineral olivine within its protostellar envelope.

Astronomy Picture of the Day for Sept. 16th

Astronomy Picture of the Day

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2011 September 16

September’s Harvest Moon
Image Credit & Copyright: Stefano De Rosa

 

 Explanation: A Full Moon rising can be a dramatic celestial sight, and Full Moons can have many names. For example, Monday’s Full Moon was the one nearest this year’s autumnal equinox for the northern hemisphere, traditionally called the Harvest Moon. According to lore the name is a fitting one because farmers could work late into the night at the end of the growing season harvesting crops by moonlight. This serene telephoto image captures this September’s harvest moonrise from Turin, Italy. In silhouette against an orange lunar disk is Turin’s hilltop Basilica of Superga.

Astronomy Picture of the Day for Sept. 14th

Astronomy Picture of the Day

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Herschel’s Cocoon
Credit: ESA, SPIRE & PACS Consortia, Doris Arzoumanian (CEA Saclay), et al. 

Explanation: In this remarkable infrared skyscape of interstellar clouds adrift in the high flying constellation Cygnus, the eye is drawn to the Cocoon Nebula. Also known as IC5146, the dusty star forming region is shown in blue hues in the Herschel Space Observatory false color image, at wavelengths more than 100 times longer than visible red light. And while visible light images show the Cocoon nebula at the end of long dark nebula Barnard 168, Hershel’s infrared view finds the cosmic Cocoon punctuating a trail of filamentary clouds of glowing dust. The filaments have widths that suggest they are formed as shockwaves from exploding stars travel through the medium, sweeping up and compressing the interstellar dust and gas. Herschel data also indicate stars are forming along the dusty filaments. The Cocoon Nebula itself is about 15 light-years wide and 4,000 light-years away.

Astronomy Picture of the Day

Astronomy Picture of the Day

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2011 September 13

Great Orion Nebulae
Image Credit & Copyright: Jesús Vargas (Astrogades) & Maritxu Poyal (Maritxu) 

Explanation: The Great Nebula in Orion, also known as M42, is one of the most famous nebulas in the sky. The star forming region’s glowing gas clouds and hot young stars are on the right in this sharp and colorful image that includes the smaller nebula M43 near center and dusty, bluish reflection nebulae NGC 1977 and friends on the left. Located at the edge of an otherwise invisible giant molecular cloud complex, these eye-catching nebulae represent only a small fraction of this galactic neighborhood’s wealth of interstellar material. Within the well-studied stellar nursery, astronomers have also identified what appear to be numerous infant planetary systems. The gorgeous skyscape spans nearly two degrees or about 45 light-years at the Orion Nebula’s estimated distance of 1,500 light-years.

Astronomy Picture of the Day

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2011 September 12

Tisdale 2 Rock Formation on Mars
Image Credit: Mars Exploration Rover Mission, Cornell, JPL, NASA

Explanation: Why does this Martian rock have so much zinc? Roughly the size and shape of a tilted coffee-table, this oddly flat, light-topped rock outcropping was chanced upon a few weeks ago by the robotic Opportunity rover currently rolling across Mars. Early last month Opportunity reached Endeavour crater, the largest surface feature it has ever encountered, and is now exploring Endeavour’s rim for clues about how wet Mars was billions of years ago. Pictured above and named Tisdale 2, the unusual rock structure was probed by Opportunity last week and is now thought to be a remnant thrown off during the impact that created nearby Odyssey crater. The resulting chemical analysis of Tisdale 2, however, has shown it to have a strangely high amount of the element zinc. The reason for this is currently unknown, but might turn out to be a clue to the history of the entire region. Opportunity is already finding rocks older than any previously studied and will continue to explore several other intriguing rock formations only now glimpsed from a distance.

Astronomy Picture of the Day

Astronomy Picture of the Day

Discover the cosmos!Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2011 September 10

Rollback from GRAIL’s Rocket
Image Credit & Copyright: Ben Cooper (Launch Photography) 

Explanation: This dramatic time-lapse photo traces a 20 minute long, late evening rollback of the lighted Mobile Service Tower at Cape Canaveral Air Force Station Launch Complex 17. Twin spacecraft are snug inside the 13 story tall Delta 2 rocket poised for launch. The duo will journey to the Moon on NASA’s Gravity Recovery and Interior Laboratory mission, GRAIL, using precision formation flying to map the Moon’s gravity field. The scene was captured prior to the first launch attempt, canceled due to upper level winds, on September 8. Further launch opportunities for GRAIL begin this morning, September 10. The GRAIL launch is the last one planned from Complex 17 on Cape Canaveral’s oldest still active pad, in use since 1957.

Astronomy Picture of the Day for Sept. 4th

 Astronomy Picture of the Day 

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 2011 September 4

 In the Shadow of Saturn
Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

Explanation: In the shadow of Saturn, unexpected wonders appear. The robotic Cassini spacecraft now orbiting Saturn drifted in giant planet’s shadow for about 12 hours in 2006 and looked back toward the eclipsed Sun. Cassini saw a view unlike any other. First, the night side of Saturn is seen to be partly lit by light reflected from its own majestic ring system. Next, the rings themselves appear dark when silhouetted against Saturn, but quite bright when viewed away from Saturn, slightly scattering sunlight, in this exaggerated color image. Saturn’s rings light up so much that new rings were discovered, although they are hard to see in the image. Seen in spectacular detail, however, is Saturn’s E ring, the ring created by the newly discovered ice-fountains of the moon Enceladus and the outermost ring visible above. Far in the distance, at the left, just above the bright main rings, is the almost ignorable pale blue dot of Earth.

Astronomy Picture of the Day for August 25

Astronomy Picture of the Day

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2011 August 25

Portrait of NGC 281
Image Credit & Copyright: J-P Metsävainio (Astro Anarchy)

Explanation: Look through the cosmic cloud cataloged as NGC 281 and it’s almost easy to miss stars of open cluster IC 1590. But, formed within the nebula, that cluster’s young, massive stars ultimately power the pervasive nebular glow. The eye-catching shapes looming in this portrait of NGC 281 are sculpted columns and dense dust globules seen in silhouette, eroded by intense, energetic winds and radiation from the hot cluster stars. If they survive long enough, the dusty structures could also be sites of future star formation. Playfully called the Pacman Nebula because of its overall shape, NGC 281 is about 10,000 light-years away in the constellation Cassiopeia. This composite image was made through narrow-band filters, but combines emission from the nebula’s hydrogen, sulfur, and oxygen atoms in a visible spectrum palette. It spans over 80 light-years at the estimated distance of NGC 281.

Astronomy Picture of the Day for 8/24:

Astronomy Picture of the Day

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2011 August 24

A Pileus Iridescent Cloud Over Ethiopia
Image Credit & Copyright: Esther Havens (Light the World)Explanation: Yes, but how many dark clouds have a multicolored lining? Pictured, behind this darker cloud, is a pileus iridescent cloud, a group of water droplets that have a uniformly similar size and so together diffract different colors of sunlight by different amounts. The above image was taken just after the picturesque sight was noticed by chance by a photographer in Ethiopia. A more detailed picture of the same cloud shows not only many colors, but unusual dark and wavy bands whose origins are thought related to wave disturbances in the cloud.

Astronomy Picture of the Day for August 23

Astronomy Picture of the Day

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2011 August 23

Aurora Over Greenland
Image Credit: Copyright: Juan Carlos Casado (TWAN)

Explanation: This aurora arched from horizon to horizon. During the current Shelios expedition to observe and learn about the northern lights, the sky last weekend did not disappoint. After sunset and some careful photographic planning, the above image was taken from the expedition’s Qaleraliq campsite in southern Greenland. Visible straight through the center of the aurora, found with a careful eye, is the Big Dipper and the surrounding constellation of the Big Bear (Ursa Major). The brightest orb on the far right is the Moon, while Jupiter can be seen even further to the right. The Shelios expedition is scheduled to last until the end of August and include live broadcasts of ongoing auroras.