giant gas cloud for gas giant jupiter

A highly sensitive imaging instrument aboard NASA’s Cassini spacecraft has revealed a massive, doughnut-shaped cloud of gas around Jupiter. The designers of the instrument — physicists from Johns Hopkins University — reported in the Feb. 27 Nature that the 60,000-ton, millions-of-miles-long ring of gas consists of water vapor. The gas is believed to result from the giant planet’s intense radiation bombardment of its moon Europa. The radiation damages the moon’s icy surface, kicking up ice molecules, and disperses them along the moon’s orbit, leaving the huge ring of gas. The researchers believe the gas acts as a source and a sink for radiation particles, and shows that Europa has considerable influence on Jupiter’s magnetic field. Cassini’s next stop is Saturn, which it will begin orbiting in July of next year.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 3/11/2003.