In a typical year, it is not uncommon for a dozen or so comets
to come within range of amateur telescopes. During the month of
October, 2010, a small comet will pass unusually close to Earth.
On Oct. 20, Comet Hartley 2 will pass just over 11 million miles
(18 million km) from Earth. That is close enough for the comet
to be seen through binoculars or even, in the darkest skies,
with the naked eye. Amateur stargazers aren’t the only ones
looking out for Hartley 2 this month. In September 2007, NASA
woke up its hibernating DI spacecraft and, in November, sent it
the maneuvering instructions to intercept Hartley 2. The
spacecraft is precisely on schedule to rendezvous with the comet
on November 4 as it approaches the sun. This week’s online
current events activity is a study of comets, the Hartley 2
Comet, and NASA’s attempt to study it. Begin your investigation
into comets by visiting Worldbook@NASA, which features excellent
overviews on many topics related to space and astronomy,
including Comets. As you read