Knowtex

Comet Garradd is expected to brighten to magnitude 10 at the beginning of July. The table shows the position of the comet in 2011.

The Solar and Heliospheric Observatory spots its 2000th comet: More than any comet-hunter in history.

Comet Hartley 2 moving eastward (up) in the constellation Cassiopeia on October 2, 2010. You can see the comet as it occults some mag 11 or so stars. The video was captured at the Starhoo Obsevatory (www.starhoo.com) in Lakeville, MA.

New data hint that a comet crashed into Neptune about 200 years ago, adding to evidence that gassy planets get hit more often than thought.

NASA's Swift satellite views Comet Lulin as it made it closest approach to Earth in February 2009.

A comet may have hit the planet Neptune about two centuries ago. This is indicated by the distribution of carbon monoxide in the atmosphere of the gas giant that researchers have now studied.

Here are all the missions NASA has sent past Earth orbit, for which it now watches and waits for data. Some will be finished in a few years, others have been flying for nearly 40, slowly gathering data and beaming it back to Earth, or potentially waiting to be discovered by someone else out there.

The discovery of volatiles in lunar material ejected by NASA's LCROSS mission suggests comets delivered much of the water at the impact site.

Europe's Rosetta probe is making its final Earth flyby as it seeks to position itself to chase down a comet in 2014.

NASA scientists have discovered glycine, a fundamental building block of life, in samples of comet Wild 2 returned by NASA's Stardust spacecraft.