Giant ice storm blows across Mars

A GIANT storm on Mars has been detected by astronomers using the Hubble Space Telescope. The storm, nearly four times the size of Texas, was made up of water-ice clouds - similar to clouds on Earth - rather than the dust clouds typically found on the red planet.

The storm, centred over the planet's northern polar ice cap, is three times larger than the largest Martian cyclone seen by the Viking Orbiter spacecraft more than 20 years ago. It covered a distance of nearly 1,100 miles across from west to east and 900 miles from north to south.

Jim Bell, assistant professor of astronomy at Cornell University in New York State, and a principal investigator of the cyclone, said a chance observation had led scientists to track the storm. Professor Bell said such storms have been observed before during the Martian summerand are similar to polar storms on Earth.

"These rapidly growing and decaying systems appear to be typical of the Martian polar weather at this season, which is mid northern summer. It's the first time we've been able to look in a detailed and dedicated way with high-resolution instruments during this season," Professor Bell said.

Within six hours of the storm being detected, it had begun to die down. It then disappeared from view, probably by moving to the other side of the planet.