Explanation:
Follow these 5 frames clockwise starting from the top left to track
the view from the
EPOXI
mission spacecraft as it approached, passed under,
and then looked back at the nucleus of
comet Hartley 2 on November 4.
Its closest approach distance was about 700 kilometers.
In fact, this encounter was
the
fifth time a spacecraft from
planet Earth has imaged a comet close-up.
But Hartley 2's nucleus is definitely the smallest one so far, its
long axis spanning
only about 2 kilometers (1.2 miles).
Though Hartley 2 is small, these stunning images showing jets of dust
and gas indicate an impressively active surface.
The jets are seen originating from the rough surface areas, with
sunlight illuminating the nucleus from the right.
Remarkably, rough areas at both ends of the elongated nucleus are joined
by a narrower, smooth waist.
The EPOXI mission
reuses the Deep Impact spacecraft that launched a probe impacting the
nucleus of comet Tempel 1 in 2005.