Astronomy Blog

Tempel 1

So now we finally get to see what comet Tempel 1 looks - sorry looked - like six minutes before it ran over NASA's Deep Impact probe at 10:52 p.m. PDT, July 3. The picture was taken by the probe's impactor targeting sensor and shows a potato-shaped nucleus.

What struck me were the features that look like impact craters. They seem to imply that the comet has been hit in the past and survived intact. So it probably isn't as loosely held together or as fragile as some may have thought.

The BBC's first episode of Stardate had an interesting segment where they looked at impacts on different types of material using a high speed camera. They fired a copper ball at a block of ice, candy floss, mashed potato and melons to demonstrate the possible outcomes. The ice stayed pretty intact but some large chunks were blown off. The copper ball passed straight through the candy floss (not surprising). The mashed potato was quite interesting as it got splattered into quite a lot of bits.

By tonight (UK) we should have some initial science observations such as initial ideas about composition and structure. There should be some spectra - IR telescopes will have been looking for emission from water vapour released by the impact.

The Faulkes Telescope North - a telescope mainly used by school groups from the UK and Hawaii - has also been taking images from Hawaii.

I wish I wasn't on a dial-up connection today.