The Astronomical Planet
The red planet Mars has inspired wild flights of imagination over the centuries, as well as intense scientific interest. Whether fancied to be the source of hostile invaders of Earth, the home of a dying civilization, or a rough-and-tumble mining colony of the future, Mars provides fertile ground for science fiction writers, based on seeds planted by centuries of scientific observations.
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Planetary Statistics of Mars:
Mars: Fourth Planet from the Sun
Diameter: 4,222 miles
Distance from the Sun: 141.6 million miles
Planetary Year: 686.98 Earth days to make one complete revolution around the Sun.
Planetary Day: 24.6 Earth hours to make one complete revolution on its axis.
Temperature: Mean; 218 K (-55 C, -67 F), surface temperature extremes - 140 K (-133 C, -207 F) to 300 K (27 C, 80 F)
Moons: 2 (Phobos, Deimos)
Chronology of Mars
Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in the solar system. This water may even have pooled into lakes or shallow oceans. But where did the ancient flood water come from, how long did it last, and where did it go?
In May 2002, scientists announced the discovery of a key piece in the puzzle: the Mars Odyssey spacecraft had detected large quantities of water ice close to the surface - enough to fill Lake Michigan twice over. The ice is mixed into the soil only a meter (about 3 feet) below the surface of a wide area near the Martian South Pole.
Environment of Mars
We know that Mars is a small rocky body once thought to be very Earth-like.
Volcanism, impacts from other bodies, movements of its crust, and atmospheric effects such as dust storms have changed its surface. Much like the other "terrestrial" planets of Mercury, Venus, and the Earth.
It has polar ice caps that grow and recede with the change of seasons. Areas of layered soils near the Martian poles suggest that the planet's climate has changed more than once. Perhaps caused by a regular change in the planet's orbit.
Water exists frozen in the polar ice caps sufficient enough to form ice clouds. Images from NASA's Mars Global Surveyor spacecraft suggest that underground reserves of water may break through the surface as springs. However, the quantity of water required to carve Mars' great channels and flood plains is not evident on, or near, the surface today. At present, Mars is too cold and its atmosphere too thin to allow liquid water to exist at the surface for very long.
Water is believed to be a central ingredient for the initiation of life. Evidence of past or present water on Mars is expected to hold clues about life on the planet in addition to unlocking its past climate history. This may also reveal information about the potential for life elsewhere in the universe. Therefore, unraveling the story of water on Mars is important. It will help us understand the evolution of all planets, including our own.
Martian tectonism, or the formation and change of a planet's crust, differs from Earth's. Earth tectonics involve sliding plates that grind against each other or spread apart in the seafloors. Martian tectonics seem to be vertical, with hot lava pushing upwards through the crust to the surface.
Mars has some remarkable geological characteristics. They Include:
- The largest volcanic mountain in the solar system. (It is named Olympus Mons and it measures 27 km high and 600 km across).
- Volcanoes in the northern Tharsis region that are so huge they deform the planet's roundness.
- A gigantic equatorial rift valley named the Valles Marineris. This canyon system stretches a distance equivalent to the distance from New York to Los Angeles. Arizona's Grand Canyon could easily fit into one of the side canyons of this great chasm.
Periodically, great dust storms engulf the entire planet. The effects of these storms are dramatic, including giant dunes, wind streaks, and wind-carved features.
Moons of Mars
Mars also has two small moons names Phobos and Deimos. Although no one knows how they formed, they may be Asteroids snared by Mars' gravity.
Information Courtesy of NASA Jet Propulsion Laboratory at Caltech
Images and Information
Check out these books for more information on Mars: