Star date: 08:16:99

Mars: Now Active, Now Dynamic, Still Red

Mars is bright in the southwestern skies this week, and new discoveries concerning the red planet make it well worth another look.

Newly released images from NASA's Mars Global Surveyor show that Mars is a different place today than it was two years ago when the spacecraft arrived - a world constantly reshaped by forces of nature including shifting sand dunes, monster dust devils, wind storms, frosts and polar ice caps that grow and retreat with the seasons.

"Mars is a cold, dry desert, but our camera has shown it is far from being a stagnant place," said Dr. Michael Malin, principal investigator for the Mars Global Surveyor camera at Malin Space Science Systems, San Diego, CA. "Over the past few months, we have captured a unique record of seasonal and meteorological events, which demonstrates that Mars is active and dynamic today."

The spacecraft's camera monitors the planet's weather on a daily basis from orbit, just like weather satellites on Earth. Today, Mars is a much more dynamic place than the planet the Viking spacecraft saw in the late 1970s. The weather has been particularly active during the past two months, as spring arrived in the southern hemisphere and autumn approached in the north. "Storm clouds have been brewing over the north polar ice cap all through the month of July, and soon, ever-increasing portions of the north polar cap will be plunged into wintertime darkness," Malin said. "As the season changes rapidly, clouds will cover much of the northern plains and it might begin to snow as the polar cap expands."

In other regions of Mars, dust devils are the prevailing weather story. A variety of new images of Mars is available on the Internet at: http://www.msss.com/

The camera aboard this mission has also revealed surprising new aspects of cloud fronts, dust devils and sand dunes on the red planet with major implications for understanding how the weather on Mars varies from season to season and from year to year. These new still images and related video products are helping scientists study these dynamic features in greater detail than ever before.

Global Surveyor carries five science instruments designed to generate a complete global portrait of Mars and its seasonal changes during a full Martian year, the equivalent of two Earth years. The spacecraft entered its primary circular mapping orbit in February, and is just beginning its second full Martian year in orbit around the red planet. Global Surveyor is the first mission in a long-term program of Mars exploration known as the Mars Surveyor Program.

Signs of frozen water were also seen on the surface of the red planet. Of course, this brings to mind the possibility of life on Mars. This will give future explorers (likely robotic) a better idea of where to look for life; that most elusive, and if found, most exotic theoretical astronomical object.

At 8:30 p.m. this week, Mars can be seen 30 degrees west of south, and 26 degrees above the horizon. At anytime during the early evening, if you see a bright, red light low on the southwestern horizon, it is most likely Mars. At magnitude 0.1, it will be brighter than nearly anything else in the sky. Mars, although small, will still present a disk when seen through a telescope or a pair of binoculars. This is the easiest way to tell if you are looking at a star or some other object.

Stars will always present a simple dot as seen through amateur astronomical equipment. Planets (with the exception of Pluto) will present a disk. Mars is seen as a small disk, but it's bright red color makes finding this world easier.

Clear skies, and good viewing.

"Understanding is joyous" - Carl Sagan