science · 01 December 2005 · 20 years ago
In 2005, the Deep Impact space probe was launched on a Delta II rocket. On 3 Jul 2005, it was to release a special impactor spacecraft to crash into comet Tempel 1. The impactor's camera relayed closeup images of the comet's nucleus before the collision (4 Jul 2005). The impact ejecta was analyzed spectroscopically, and was found to have more dust and less ice then expected. Also identified were clays, carbonates, sodium, crystalline silicates, and a surprisingly high number of organic molecules. The comet nucleus was highly porous, with up to 80% empty space. Deep Impact continued as the EPOXI mission to the hyperactive comet Hartley 2 (4 Nov 2010), comet Garradd (Jan 2012) and comet Ison. It abruptly fell silent (8 Aug 2013), and was declared dead on 20 Sep 2013.
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