X-SciTech

Jupiter's Secret Rings Revealed

By CBSNews.com staff CBSNews.com staff

September 15, 1998 / 7:40 PM EDT / CBS

As part of the largest planet in the solar system, Jupiter's rings have long been a curiosity. Astronomers say the NASA spacecraft Galileo has made breakthrough findings, reports CBS News Correspondent Jerry Bowen.

Jupiter's mysterious rings, the largest more than 70,000 miles wide, are the stuff of moon dust say astronomers. They are the result of constant collisions between meteoroids and Jupiter's four closest moons, or satellites.

"This satellite is constantly being pelted by a hailstorm of high-speed projectiles," says Cornell University researcher Joseph Burns.

Burns and Cornell researcher Joseph Veverka say the satellites are continually hit by pieces of comets and asteroids, ranging in size from small dust grains up to large objects. The resulting impacts generate particles which constantly feed the rings.

Images of the four little pock-marked moons taken by NASA's Galileo spacecraft provide the evidence. The pictures illustrate the beating the moons have been taking for billions of years.

"The process is on-going" says Burns. "We're continually regenerating the same ring over and over again, with the source being these mother moons."

Galileo revealed something else -- an additional ring around Jupiter. High resolution imagery shows Jupiter's main ring and its adjacent halo ring which are closest to the planet.

However the third outside ring, the gossamer ring, is actually a double -- a ring within a ring. Astronomers were stunned at the finding.

"There was a sense of awe" says Michael Belton, of NASA's Galileo's imaging team. "I certainly sat there with my mouth slightly open, thinking, this is a remarkable result."

The researchers say it is far from over. Jupiter has 16 moons, and just within the past year, the Galileo spacecraft may have detected signs of an ocean beneath the surface of its icy moon Europa. With the possibility of an ocean, scientists are pondering questions of life on the moons.

Last month at California's Monterey Bay Aquarium, NASA scientists began testing the prototype of a probe that may one day answer the question.

In October, the device will be tested in undersea volcanic vents off Hawaii, the kind of conditions where primitive life forms are most likely to exist -- if they do indeed exist on Europa.