No comet has ever been visited twice before.
Therefore, the unprecedented pass of the
near Comet Tempel 1
earlier this week gave humanity a unique opportunity to see how the nucleus of a comet changes over time.
Changes in the
nucleus of Comet Tempel 1
were of particular interest because the comet was
hit with an
from the passing
Deep Impact spacecraft in 2005.
Pictured above is one digitally sharpened image of Comet Tempel 1 near the closest approach of
many features imaged in 2005, including craters, ridges, and seemingly smoother areas.
Few firm conclusions are yet available,
but over the next few years astronomers who
specialize in comets and the understanding the early Solar System will be pouring over
these images looking for new clues as to how
Comet Tempel 1 is composed, how the
2005 impact site now appears, and how general features of the comet have evolved.