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6 March 2014 1:04 pm ,
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Antiretroviral drugs can protect people from becoming infected by HIV. But so-called pre-exposure prophylaxis, or PrEP...
Two studies show that eating a diet low in protein and high in carbohydrates is linked to a longer, healthier life, and...
Considered an icon of conservation science, researchers at World Wildlife Fund (WWF) headquarters in Washington, D.C.,...
The new atlas, which shows the distribution of important trace metals and other substances, is the first product of...
Early in April, the first of a fleet of environmental monitoring satellites will lift off from Europe's spaceport in...
Since 2000, U.S. government health research agencies have spent almost $1 billion on an effort to churn out thousands...
Magdalena Koziol, a former postdoc at Yale University, was the victim of scientific sabotage. Now, she is suing the...
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ScienceShot: Comet Revealed as a Giant Dog Bone
4 November 2010 12:40 pm
At about 10 a.m. this morning, the EPOXI spacecraft screamed by the icy nucleus of comet Hartley 2 at 43,000 kilometers per hour. The fifth comet ever imaged so close up, Hartley 2 looks a bit like a dog bone, or a dumbbell, or, more technically, a highly elongated triaxial thingy. The shape of the comet, which is only about a kilometer in size, is reminiscent of Comet Borrelly, first sighted by the Deep Space 1 spacecraft in 2001, only more so. Presumably, Hartley 2 was once two separate bodies that came together. Or, it could have always been a solitary, barely compacted collection of rubble that came close to splitting in two when it spun too fast. Today, the sun's warmth is driving off water vapor, other gases, and dust—especially in bright jets seen streaming off the far end—that have been locked up in the comet since the solar system formed 4.6 billion years ago. This afternoon, team scientists will release processed images and perhaps make some sense of the rough ends and smooth neck between, something never seen before.
See more ScienceShots.