Guardian:
NASA's
Epoxi
mission will sweep past the Hartley 2 comet on Thursday and
take detailed measurements and images. Comets are formed from
space rubble and vary in size from a few hundred meters in
diameter to tens of kilometers. "Comets were once thought to be
roughly similar in shape and structure," said Mark Bailey of
Armagh Observatory in Northern Ireland. "But the more probes
that we fly past them, the more differences we find." Because
scientists believe that water and complex organic materials
detected on comets may have played a key role in the evolution
of life on Earth, they are interested in studying them close
up. Hartley 2 was also in the news last week. Astronomers
attributed
two meteors to the comet, which, being small, is not
expected to shed such fireballs. The images below of the comet
come from the Arecibo Observatory in Puerto Rico.
