This image of comet Lulin was made Feb. 2, 2009 by Rolando Ligustri using the RAS Observatory in New Mexico. The green ball is the comet's atmosphere, or coma, measuring about 311,000 miles (500,000 km) wide, or three times the diameter of Jupiter. The coma contains cyanogen (CN) and diatomic carbon (C2), two gases that glow green when exposed to sunlight. Credit: R. Ligustri (www.castfvg.it), RAS Observatory, used with permission
