SPACE : Astronomers Find Huge Cloud

Astronomers today reported the discovery of what may be the largest visible structure in the solar system--a 20-million-mile-long cloud of sodium streaming away from Jupiter.

A team from Boston University said it found a huge, cloud-like structure, or nebula, made of sodium atoms stretching from Jupiter into interplanetary space.

Pictures taken by the scientists show the cloud has a visible span of at least 20 million miles--400 times the radius of Jupiter, the largest planet in the solar system.

“This is an enormous structure, perhaps the largest, permanently visible feature in the solar system,” said Michael Mendillo, an astronomy professor who led the study based on telescope observations made at the McDonald Observatory in Texas from November through February.

For about 15 years, astronomers have known that Jupiter and Io, its moon, are surrounded by sodium clouds but the size of those clouds had not been determined and it was thought that they remained relatively close to the giant planet.