Content-Type: text/html
Wikipedia: Mars
HomePage | RecentChanges | Preferences
You can edit this page right now! It's a free, community project
Fourth planet in the Solar system. Named for the Roman god of war, counterpart of the Greek Ares?, on account of its red color. Mars has always fascinated people. Its red, fiery appearance was mysterious and intriguing. Mars has only a quarter the surface area of Earth and only 1/10th the mass. Mars has two small moons, both small and oddly shaped, possibly representing captured asteroids. Mars has polar ice caps that contain frozen water and carbon dioxide. An extinct volcano, [Olympius Mons]?, is, at 25 km, the tallest mountain in the solar system. Mar's atmosphere? is very thin, the surface air pressure is only 7.5 millibars compared to an average 1013 millibars on Earth. The atmosphere on Mars is 95% carbon dioxide with very little oxygen.
Mars has an important place in human imagination due to the old belief that life existed on Mars. This was supposed because of observations of linear features on the surface that appeared artificial and seasonal changes in the brightness of some areas that were thought to be caused by vegetation growth. This gave rise to many stories concerning Martians. The linear features are now know to be non-existent or in some cases, natural dry watercourses. The color changes have been ascribed to dust storms. Recently analysis of [[meteorite]s thought to have come from Mars show some features that may be fossils of single celled organisms.
Mars Facts:
- equatorial diameter: 4,200 miles ( 6,700 kilometers)
- mass: 0.11 of the Earth
- mean relative density: 3.95
- surface gravity: 0.38
- surface area relative to Earth: 0.28
- farthest distance from the Sun: 154,900,000 miles (249,200,000 kilometers)
- closest approach to earth approx.: 48,700,000 miles (78,390,000 kilometers)
- orbital period: 687 earth days
- rotational period: 24hrs. 37mins.
- low temperature: -305 F (-187 C)
- satellites : 2, Phobos? (from Greek Fear) and Deimos? (from Greek Panic)
Natural Mars's satellites
Name of the satellite | Mean Distance
from parent
Planet (km) | iDiameter of satellite (km) |
Phobos? | 9,300 | 23 |
Deimos? | 23,500 | 10 |
The history of Mars exploration has been full of unsuccessful satellite exploration missions. The first successful satellite to orbit Mars was [Mariner 4]? in 1965?. The Soviets landed a lander in 1974? but the first scientifically important landing was the American [Viking I]? in 1976?. The most successful recent satellite is [Mars Global Surveyor]? which photographed Mars at much higher resolution than previous surveys.
The International Astronomical Union's [Working Group for Planetary System Nomeclature] is responsible for naming Martian surface features.
See also: