Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2006 May 23
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Comet Schwassmann-Wachmann 3 Passes the Earth
Credit & Copyright: Thad V'Soske (

Explanation: Rarely does a comet pass this close to Earth. Last week, dedicated astrofilmographers were able to take advantage of the close approach of crumbling 73P / Comet Schwassmann-Wachmann 3 to make time-lapse movies of the fast-moving comet. Large comet fragments passed about 25 times the Moon's distance from the Earth. The above time lapse movie of Fragment B of Comet Schwassmann-Wachmann 3 over Colorado, USA was taken during a single night, May 16, with 83 consecutive 49-second exposures. Some observers report being able to perceive the slight motion of the comet with respect to the background stars using only their binoculars and without resorting to the creation of fancy digital time-lapse movies. Fragment B of Comet Schwassmann-Wachmann 3 became just barely visible to the unaided eye two weeks ago but now is appearing to fade as the comet has moved past the Earth and nears the Sun. Many sky enthusiasts will be on the watch for a particularly active meteor shower tonight as the Earth made its closest approach to orbit of Comet Schwassmann-Wachmann 3 late yesterday.

Tomorrow's picture: five quasars?

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