In a dress rehearsal for the rendezvous between NASA's Deep Impact spacecraft and comet 9P/Tempel 1, the Hubble Space Telescope captured dramatic images of a new jet of dust streaming from the icy comet.

The images are a reminder that Tempel 1's icy nucleus, roughly the size of central Paris, is dynamic and volatile. Astronomers hope the eruption of dust seen in these observations is a preview of the fireworks that may come 4 July, when a probe from the Deep Impact spacecraft will slam into the comet, possibly blasting off material and giving rise to a similar dust plume.

Credit: NASA, ESA, P. Feldman (Johns Hopkins University), and H. Weaver (Applied Physics Lab)