Nasa's Deep Impact probe has flown by Comet Hartley 2. The first pictures revealed a roughly 1.5km-long, peanut-shaped object with jets of gas streaming from its surface. The pass, which occurred about 23 million km from Earth, was only the fifth time a spacecraft had made a close approach to a comet.
Nasa said it would take many hours to retrieve all of the data recorded by Deep Impact's two visible-light imagers and one infrared sensor. But the initial pictures to get to ground gave a fascinating view of the comet's icy body, or nucleus.
"The dominant signature is [the] two rough ends and a smooth middle," said Dr Jessica Sunshine, the mission's deputy principal investigator from the University of Maryland, College Park.
"What we see is that where the activity is, where the jets are, is the rough areas. And the middle - in our best current interpretation - we think is fine grained material that has been re-distributed across the comet and collected in a topographic low."
The information from the flyby should give scientists further insight into the diverse properties and behaviours of what are some of the Solar System's most remarkable objects.
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