Comet surprise makes it visible to naked eye

• Comet 17P/Holmes explodes, making its cloud bigger than Jupiter
• Comet can be seen in the northern sky, in the constellation Perseus
• Scientist: "This is a once-in-a-lifetime event to witness"

 
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."

"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.

http://www.cnn.com/2007/TECH/space/11/05/brighter.comet.ap/index.html