Hours after the Deep Impact space probe flew within about 435 miles of comet Hartley 2 on Thursday morning, images beamed back to Earth revealed a body shaped rather like a peanut or an overturned bowling pin, with two bulbous, roughened edges and a smooth band in between.
The images coming in were "just amazing," team scientist Jessica Sunshine of the University of Maryland said at a news conference.
The ice and debris that make up a comet are thought to be leftovers from the solar system's early development, when the planets were still coalescing, said astronomer Michael A'Hearn of the University of Maryland, the mission's principal investigator. Thus, learning about their composition could help reveal what our early solar system looked like.
The fly-by was only the fifth time a spacecraft has had such an up-close and personal look at a comet — and each of those encounters has provided new information, the scientists said.