Comet Smasher Nears Launch

[zavvy]

<b>Comet Smasher Nears Launch</b><br /><br />LINK<br /><br />What's the best way to see inside a comet? Shattering it with a chunk of metal could be the answer, if a NASA mission due to be launched next week goes to plan.<br /><br />The Deep Impact spacecraft is due to take off from Cape Canaveral in Florida at about 18:48 GMT on Wednesday 12 January and will meet comet Tempel 1 roughly 134 million kilometres from Earth, just beyond the orbit of Mars. It will then release a 372-kilogram copper probe into the path of the comet.<br /><br />On 4 July, the comet and probe will collide at about 37,000 kilometres per hour, blasting a deep hole in the comet's nucleus that should reveal what lies beneath the icy surface. The porous surface of the comet should shatter on impact (see film), spraying detritus outwards to leave a crater that could be ten storeys deep.<br /><br />The probe carries a camera that will relay pictures of its death dive back to the Deep Impact mother ship, which will stay at a safe distance of at least 500 kilometres to film the crash and use an array of instruments to analyse the debris. "We will be capturing the whole thing on the most powerful camera to fly in deep space," says astronomer Michael A'Hearn, principal investigator for the project, from the University of Maryland, College Park.<br /><br />NASA's orbiting telescopes Chandra, Hubble and Spitzer will also watch the event, and the explosion generated by the $267-million mission should even be visible to telescopes on Earth.<br /><br />Ancient snowballs<br /><br />Comets are made of material left over from the formation of the Solar System, and astronomers say that studying the interior of Tempel 1 will allow them to step back more than 4 billion years in time, giving them clues about the chemicals that formed Earth and its neighbouring planets.<br /><br />The probe, roughly the size of a washing machine, is made of copper