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.

2003 March 9 Farewell Jupiter Credit: Cassini Imaging Team, Cassini Project, NASA

Explanation: Next stop: Saturn. The Cassini spacecraft, launched from Earth in 1997, has now swung past Jupiter and should arrive at Saturn in the year 2004. Pictured to the left is a parting shot from Cassini in 2001 January that would not have been possible from Earth: Jupiter showing a crescent phase. From the Earth and all points sunward of Jupiter, the gas giant will always appear more fully lit than a crescent. Recent analysis of Jupiter images taken from Cassini bolsters indications that clouds well up from below in the dark colored belts, not the light colored zones, as believed previously. After arriving at Saturn, Cassini will decelerate to orbit the ringed world and send a probe to its enigmatic moon Titan.