This photo, captured by the NASA Hubble Space Telescope's Advanced Camera for Surveys, is Hubble's latest view of an expanding halo of light around the distant star V838 Monocerotis, or V Mon, caused by an unusual stellar outburst that occurred back in January 2002. A burst of light from the bizarre star is spreading into space and reflecting off of surrounding circumstellar dust. As different parts are sequentially illuminated, the appearance of the dust changes. This effect is referred to as a "light echo".
NASA's Swift satellite views Comet Lulin as it made its closest approach to Earth in February 2009. Lulin, like all comets, is a clump of frozen gases mixed with dust. These 'dirty snowballs' cast off gas and dust whenever they venture near the sun. Comet Lulin, which is formally known as C/2007 N3, was discovered in 2008 by astronomers at Taiwan's Lulin Observatory. Lulin passed closest to Earth -- 38 million miles, or about 160 times farther than the moon -- late on the evening of Feb. 23, 2009, for North America.
A prominence eruption from the sun is seen in this image taken by NASA's Solar Dynamics Observatory on March 30. With a telescope and the right kinds of filters, an amateur astronomer can view prominences on the sun, too.
The Cat's Eye Nebula, NGC 6543, located in the constellation of Draco, is seen in this undated image.
A comet struck the planet Neptune some 200 years ago, leaving a blotch of carbon monoxide in the upper atmosphere.
With a clear sky and a good pair of binoculars, you should have no trouble getting a glimpse of Uranus.
An artists rendering image shows an exoplanet 6 times the Earth circulate around its low-mass host star at a distance equal to 1/20th of the Earth-Sun distance. European astronomers announced they had found 32 new planets orbiting stars outside our solar system on Monday. They believe their find means that 40 percent or more of Sun-like stars have such planets. The host star in this image is a companion to two other low-mass stars, seen in the distance.