Mars in a Dust Cocoon

By: Alan MacRobert June 25, 2004 0

The Hubble Space Telescope captured a dramatic change in Mars's weather.

Courtesy NASA, James Bell (Cornell University), Michael Wolff (STScI), and the Hubble Heritage Team (STScI/AURA).

The dust storm that wiped out Martian surface features
in amateur telescopes last July could hardly be more dramatic than in the pair of natural-color Hubble
Space Telescope images released last week. When the first picture
was taken, yellow-brown dust clouds were already beginning to shroud
the Hellas basin (medium-bright area at 4 o'clock position on the limb)
and the North Polar Cap (top). They soon spread and multiplied to envelop
the globe. Both images show nearly the same Martian hemisphere, with
dark Sinus Sabaeus and Sinus Meridiani near center.

About Alan MacRobert

Alan M. MacRobert became an avid Sky & Telescope subscriber in 1966 at age 14, joined the editorial staff in 1982, and is now a senior contributing editor, semi-retired. He played a role in practically every part of the magazine and the company's other products for more than a generation, both on the amateur-observing side and the science-reporting side. In 1994 a book collection of his observing how-tos and telescopic sky tours was published as Star Hopping for Backyard Astronomers. He has produced This Week's Sky at a Glance online every week since 1989.