NASA IotD and APoD

zxn0 via YahooPipes — Fri, 25 May 2012 00:00:00 +0000

2012 May 25

Scorpius in Red and Blue
Image Credit & Copyright: John Davis

Explanation: Cosmic dust clouds dim the light of background stars. But they also reflect the light of stars nearby. Since bright stars tend to radiate strongly in the blue portion of the visible spectrum, and the interstellar dust scatters blue light more strongly than red, the dusty reflection nebulae tend to be blue. Lovely examples are the wispy blue reflection nebulae near bright, hot stars Pi and Delta Scorpii (upper left and lower right) in this telescopic skyscape from the head of the constellation Scorpius. Of course, the contrasting red emission nebulae are also caused by the hot stars' energetic radiation. Ultraviolet photons ionize hydrogen atoms in the interstellar clouds producing the characteristic red hydrogen alpha emission line as the electrons recombine. About 600 light-years away, the nebulae are found in the second version of the Sharpless Catalog as Sh2-1 (left, with reflection nebulae VdB 99) and Sh2-7. At that distance, this field of view is about 40 light-years across.

Tomorrow's picture: edgy island universe

NASA IotD and APoD

zxn0 via YahooPipes — Thu, 24 May 2012 04:00:00 +0000

Carpenter's Flight

50 years ago today, Scott Carpenter flew the second American manned orbital flight on May 24, 1962. He piloted his Aurora 7 spacecraft through three revolutions of the earth.
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NASA IotD and APoD

zxn0 via YahooPipes — Thu, 24 May 2012 00:00:00 +0000

2012 May 24

All the Water on Europa
Illustration Credit & Copyright: Kevin Hand (JPL/Caltech),
Jack Cook (Woods Hole Oceanographic Institution), Howard Perlman (USGS)

Explanation: How much of Jupiter's moon Europa is made of water? A lot, actually. Based on the Galileo probe data acquired during its exploration of the Jovian system from 1995 to 2003, Europa possesses a deep, global ocean of liquid water beneath a layer of surface ice. The subsurface ocean plus ice layer could range from 80 to 170 kilometers in average depth. Adopting an estimate of 100 kilometers depth, if all the water on Europa were gathered into a ball it would have a radius of 877 kilometers. To scale, this intriguing illustration compares that hypothetical ball of all the water on Europa to the size of Europa itself (left) - and similarly to all the water on planet Earth. With a volume 2-3 times the volume of water in Earth's oceans, the global ocean on Europa holds out a tantalizing destination in the search for extraterrestrial life in our solar system.

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Tomorrow's picture: red and blue

NASA IotD and APoD

zxn0 via YahooPipes — Wed, 23 May 2012 00:00:00 +0000

2012 May 23

SpaceX's Falcon 9 Launches to the Space Station
Image Credit: NASA

Explanation: This fire-breathing Dragon can fly. Pictured above yesterday, SpaceX Corporation's Falcon 9 rocket capped with a Dragon spacecraft lifted off from Cape Canaveral, Florida, USA. The successful launch was significant not only because it demonstrated that a private company has the ability to re-supply the International Space Station (ISS), but also that spaceflight has taken a significant step away from being an endeavor that only big governments can do with public money. If all continues as planned, the robotic Dragon will dock with the ISS this weekend. Over the next two weeks, the ISS Expedition 31 crew will then unload Dragon and refill it with used scientific equipment. In about three weeks, the ISS's robotic arm will then undock Dragon and move it to where it can fire its rockets. Soon thereafter the Dragon capsule is expected to reenter the Earth's atmosphere, deploy its parachutes, splash down in the Pacific Ocean off the coast of California, and be recovered.

Now 444 Codes: The Astrophysics Source Code Library
Tomorrow's picture: aqua europa

NASA IotD and APoD

zxn0 via YahooPipes — Tue, 22 May 2012 00:00:00 +0000

2012 May 22

A Partial Solar Eclipse over Texas
Image Credit & Copyright: Jimmy Westlake (Colorado Mountain College) & Linda Westlake

Explanation: It was a typical Texas sunset except that most of the Sun was missing. The location of the missing piece of the Sun was not a mystery -- it was behind the Moon. Sunday night's partial eclipse of the Sun by the Moon turned into one of the best photographed astronomical events in history. Gallery after online gallery is posting just one amazing eclipse image after another. Pictured above is possibly one of the more interesting posted images -- a partially eclipsed Sun setting in a reddened sky behind brush and a windmill. The image was taken Sunday night from about 20 miles west of Sundown, Texas, USA, just after the ring of fire effect was broken by the Moon moving away from the center of the Sun. Coming early next month is an astronomical event that holds promise to be even more photographed -- the last partial eclipse of the Sun by Venus until the year 2117.

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Tomorrow's picture: fire dragon

NASA IotD and APoD

zxn0 via YahooPipes — Mon, 21 May 2012 00:00:00 +0000

2012 May 21

A Close Pass of Saturn's Moon Dione
Image Credit: Cassini Imaging Team, ISS, JPL, ESA, NASA

Explanation: What's that past Dione? When making its closest pass yet of Saturn's moon Dione late last year, the robotic Cassini spacecraft snapped this far-ranging picture featuring Dione, Saturn's rings, and the two small moons Epimetheus and Prometheus. The above image captures part of the heavily cratered snow-white surface of the 1,100 kilometer wide Dione, the thinness of Saturn's rings, and the comparative darkness of the smaller moon Epimetheus. The image was taken when Cassini was only about 100,000 kilometers from the large icy moon. Future events in Cassini's continuing exploration of Saturn and its moons include tomorrow's flyby of Titan and imaging the distant Earth passing behind Saturn in June.

Gallery: Images of Yesterday's Eclipse
Tomorrow's picture: a cool eclipse image

NASA IotD and APoD

zxn0 via YahooPipes — Sun, 20 May 2012 00:00:00 +0000

2012 May 20

A Partial Eclipse Over Manila Bay
Credit & Copyright: Armando Lee (Astron. League Philippines), F. Naelga Jr., 100 Hours of Astronomy (IYA2009)

Explanation: What's happened to the setting Sun? An eclipse! In early 2009, the Moon eclipsed part of the Sun as visible from parts of Africa, Australia, and Asia. In particular the above image, taken from the Mall of Asia seawall, caught a partially eclipsed Sun setting over Manila Bay in the Philippines. Piers are visible in silhouette in the foreground. Eclipse chasers and well placed sky enthusiasts captured many other interesting and artistic images of the year's only annular solar eclipse, including movies, eclipse shadow arrays, and rings of fire. Today parts of the Sun again will become briefly blocked by the Moon, again visible to some as a partial eclipse of a setting Sun. A small swath of Earth, however, will be exposed to the unusual ring of fire effect when the Moon is completely surrounded by the glowing light of the slightly larger Sun.

APOD Collection: Images of Past Partial Solar Eclipses
Gallery: Images of Today's Eclipse
Tomorrow's picture: many moons

NASA IotD and APoD

zxn0 via YahooPipes — Sat, 19 May 2012 00:00:00 +0000

2012 May 19

Annular Solar Eclipse
Image Credit & Copyright: Mikael Svalgaard

Explanation: Tomorrow, May 20, the Moon's shadow will race across planet Earth. Observers within the 240-300 kilometer wide shadow track will be able to witness an annular solar eclipse as the Moon's apparent size is presently too small to completely cover the Sun. Heading east over a period of 3.5 hours, the shadow path will begin in southern China, cross the northern Pacific, and reach well into North America, crossing the US west coast in southern Oregon and northern California. Along the route, Tokyo residents will be just 10 kilometers north of the path's center line. Of course a partial eclipse will be visible from a much larger area within North America, the Pacific, and eastern Asia. This safely filtered telescopic picture was taken during the annular eclipse of January 15, 2010 from the city of Kanyakumari at the southern tip of India.

Tomorrow's picture: sun block