Mars

The @stro object for the week of 03/27/2000

image courtesy of STSCI

Mars. The planet Mars gets its name from the Roman god of war. Mars is the fourth planet from the Sun and is one of the "terrestrial planets". Mars has a reddish hue brought about by the high amount of iron oxide (rust) in its soil and the dust in its atmosphere.

Mars is easily visible with the naked eye when viewable from Earth and has been known about for countless millennia. Our understanding of the nature of Mars has made leaps and bounds since it was announced by nineteenth century astronomer Percival Lowell that Mars had water canals which crossed its surface and subsequent claims by others that Mars was a lush paradise with intelligent life. Lowell was incorrect - there are no water flows on Mars today, but there is evidence of past water flows and floods in the form of the erosion the water left behind.

Mars continues to be the focus of intense research and the recipient of several spaceprobes beginning with Mariner 4 in 1965. These probes have beamed back information about this mysterious planet, but many questions still remain. Most notable of these questions is whether there was ever past, or even present, life on the planet. Space travel to Mars, like the other planets, remains fairly treacherous and far from routine as evidenced by the failure of two of the most recent of these Martian spaceprobe missions, NASA's Mars Polar Lander and Mars Climate Orbiter missions. There have been some spectacular successes however, such as the Mars Pathfinder rover and the Mars Global Surveyor missions. Other missions to Mars are in development including a plan to return Martian soil to Earth for analysis. Human spaceflight to Mars remains a goal that many world space agencies envision, even possibly within the next two decades.

Some other interesting facts about Mars:

• Martian geology has produced some interesting features on Mars, such as Olympus Mons, which is the largest known mountain in the solar system, and the infamous "Face on Mars" that has since turned out to be just another eroded plateau in better images provided by Mars Global Surveyor.
• Mars has a diameter of 6794 kilometers (4221 miles) compared to Earth's 12756 km (7926 mi). However, the Martian land surface area is equivalent to Earth's since there is no ocean water to submerge the land.
• Mars has two moons named Phobos and Deimos.
• It has permanent polar ice packs.
• The Martian surface shows clear signs that wind and water related erosion has taken place. Present day erosion is caused by wind.
• Mars has radical climate temperature differences spurred on by an elliptical orbit around the Sun, among other things. This elliptical orbit produces a temperature variation as high as 30 Celsius (86 Fahrenheit). While Mars does have a thin cloud layer it lacks a thick atmosphere to hold in and regulate heat. Although the average temperature is around -55 C (-67 F) it can vary on the planet from -133 C (-207 F) at the poles to 27 C (80 F) on a summer day.

Current information for Mars (North America):

Rise: 06:39 PST

Set: 21:07 PST

Magnitude: ~1.4

Constellation: Aries

more info from SEDS...

pictures of Martian cloud formations from STSCI...

more info on the Mars Pathfinder Rover mission...

more info on the Mars Global Surveyor...