Scan the sky just below and to the right of Saturn, and look for a fuzzy blob of light. That's Comet Lulin.
Unlike the 1990s comets, Lulin is a relatively small object, with its icy nucleus estimated to be only a few miles across. But its coma has expanded under the sun's influence to the size of Jupiter. It is the sunlight reflected off that coma that makes it visible from Earth.
Lulin's greenish glow is caused by the fluorescence of carbon atoms in the coma as they are struck by sunlight, Bodewits said. But the color might not be apparent to the naked eye or through binoculars.
It might also be hard to spot the odd double tail visible in Lulin photos. A smear of dust appears on both sides of the comet, and a blue-green tail of ionized gas is streaming off the comet, driven away from the sun by the solar wind.
The comet will be visible for several weeks. It will move noticeably westward relative to the stars each night, but it will also fade quickly through March as it speeds away from Earth toward deep space.
LULIN VIEWING
For a telescopic view of Lulin, weather permitting:
* The Maryland Science Center: Open this evening until 8 p.m. Extended evening observatory hours next Friday, Feb. 27, to at least 9 p.m.
* Streetcorner Astronomer Herman Heyn: after 7 p.m. Sunday in the 3100 block of St. Paul St., Charles Village.
* Anne Arundel County Community College Observatory: Open Feb. 28. Call 410 777-1820
* Maryland Space Grant Observatory at Johns Hopkins University: Open 8 to 11 p.m. Fridays. Call 410-516- 6525
* University of Maryland, College Park: Open 8 p.m. tonight and March 5. Check Web site: www.astro.umd.edu/openhouse
