Seen anything interesting in the sky lately? I've been looking every night, but haven't been able to see it so far.
The progression of comet Pan-STARRS across the night sky in March 2013 is shown in this NASA graphic.
Comet ISON is a promising celestial object that was discovered by amateur astronomers in 2012 and is expected to make its closest approach to the sun in late November. The comet will be only 800,000 miles (1.2 million km)from the sun at its closest point, and could put on a dazzling night sky spectacle. But it could also fizzle out, NASA scientists have said. Some predict it could light up the Earth like a bright full moon, but we will have to wait and see.