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STS-120 day 2 highlights

Flight Day 2 of Discovery's mission focused on heat shield inspections. This movie shows the day's highlights.

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STS-120 day 1 highlights

The highlights from shuttle Discovery's launch day are packaged into this movie.

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STS-118: Highlights

The STS-118 crew, including Barbara Morgan, narrates its mission highlights film and answers questions in this post-flight presentation.

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 Mission film

STS-120: Rollout to pad

Space shuttle Discovery rolls out of the Vehicle Assembly Building and travels to launch pad 39A for its STS-120 mission.

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Dawn leaves Earth

NASA's Dawn space probe launches aboard a Delta 2-Heavy rocket from Cape Canaveral to explore two worlds in the asteroid belt.

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Dawn: Launch preview

These briefings preview the launch and science objectives of NASA's Dawn asteroid orbiter.

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Comet brightens a million times, visible to naked eye
BY KULVINDER SINGH CHADHA
ASTRONOMY NOW

Posted: October 25, 2007


Comet Holmes in outburst captured remotely from RAS network (N.M.). Image: Ernesto Guido & Giovanni Sostero (AFAM, Remanzacco Observatory).

A comet in the direction of the constellation Perseus has unexpectedly brightened by a million times in the past 24 hours.

The source of this extraordinary event is comet 17P/Holmes, which is normally a magnitude 17 object -- just beyond the capability of the Hubble Space Telescope. The dwarf planets Pluto and Eris are magnitude 13.67 and 18.7 respectively.

But now the comet is visible to the naked eye, having brightened yesterday to magnitude 2.7, with current estimates stating its magnitude to be as high as 2.2 (1.6 times as bright). The actual figure is fairly subjective at this moment in time, though amateur astronomers say it compares well with the stars gamma persei and delta persei in Perseus.


Find Comet Holmes in the constellation Perseus looking northeast after sunset. AN Graphic.

Reports from the amateur astronomers (from as far afield as North America, Spain, Iran and Japan) suggest a golden-hued, fuzzy, star or planet-like appearance, with a bright 20 arcsecond interior surrounded by a greenish coma (suggesting the presence of cyanogen).

The reason for 17P/Holmes sudden brightness may be due to the comet's core breaking up, or possibly because of a collision with an unseen object. Details are sketchy at the moment and 17P/Holmes is small and 1.6 astronomical units away from Earth, making it difficult to discern any details, even with large telescopes.

Stargazers in Britain hoping to see 17P/Holmes may be thwarted by the weather. However, the comet is thought to have only begun brightening, allowing ample opportunity to make observations over the next few weeks. Early reports suggest that 17P/Holmes may have begun to grow a tail already.

2009 Yearbook
This 132-page special edition features the ultimate observing guide for 2009, a review of all the biggest news stories of 2008, in depth articles covering all aspects of astronomy and space missions for 2009, previews of International Year of Astronomy events and much, much more.
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Infinity Rising
This special publication features the photography of British astro-imager Nik Szymanek and covers a range of photographic methods from basic to advanced. Beautiful pictures of the night sky can be obtained with a simple camera and tripod before tackling more difficult projects, such as guided astrophotography through the telescope and CCD imaging.
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Starry Night
Explore the Universe with these new versions of the award-winning Starry Night Software. Available now from the Astronomy Now Store.
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Exploring Mars
Astronomy Now is pleased to announce the publication of Exploring Mars. The very best images of Mars taken by orbiting spacecraft and NASA's Spirit and Opportunity rovers fill up the 98 glossy pages of this special edition!
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Mars rover poster
This new poster features some of the best pictures from NASA's amazing Mars Exploration Rovers Spirit and Opportunity.
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