Comet draws scientific, amateur interest
KNOXVILLE, Tenn. - A comet that has unexpectedly brightened in the
past couple of weeks and now is visible to the naked eye is
attracting professional and amateur interest.
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Paul Lewis, director of astronomy outreach at the University of
Tennessee, is drawing students to the roof of Nielsen Physics
Building for special viewings of Comet 17P/Holmes.
The comet is exploding and its coma, a cloud of gas and dust
illuminated by the sun, has grown to be bigger than the planet
Jupiter. The comet lacks the tail usually associated with such
celestial bodies but can be seen in the northern sky, in the
constellation Perseus, as a fuzzy spot of light about as bright as
the stars in the Big Dipper.
"This is truly a celestial surprise," Lewis said. "Absolutely
amazing."
Until Oct. 23, the comet had been visible to modern astronomers
only with a telescope, but that night it suddenly erupted and
expanded.
A similar burst in 1892 led to the comet's discovery by Edwin
Holmes.
"This is a once-in-a-lifetime event to witness, along the lines of
when Comet Shoemaker-Levy 9 smashed into Jupiter back in 1994,"
Lewis said.
Scientists speculate the comet has exploded because there are
sinkholes in its nucleus, giving it a honeycomb-like structure. The
collapse exposed comet ice to the sun, which transformed the ice
into gas.
"What comets do when they are near the sun is very unpredictable,"
Lewis said. "We expect to see a coma cloud and a tail, but this is
more like an explosion, and we are seeing the bubble of gas and
dust as it expands away from the center of the blast."
Experts aren't sure how long the comet's show will last, but
estimate it could be weeks if not months. Using a telescope or
binoculars help bring the comet's details into view, they
said.
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Information from: The Knoxville News Sentinel,
http://www.knoxnews.com