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Mars: Facts

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Mars is known as “the red planet.” It can be seen with the naked eye from the earth and is actually red in color. No one knows who discovered Mars because it has been known by humans since prehistoric times. Its red color is due to rust in the soil on its surface. It was given the name Mars by the Romans after their god of war who was called Mars. The planet Mars was written about and studied by ancient Egyptians, Romans, Greeks, and the Chinese.

Mars is the fourth planet from the sun and orbits at an average distance of 141,633,260 miles (227,936,640 km) from the sun. A day on Mars lasts slightly longer than a day on Earth at 24 hours and 37 minutes. A year lasts 687 days - almost 2 Earth years!

Solar System

Mars is dry and dusty. It often has great dust storms that have carved and shaped its surface. The temperatures there can be as hot as 23° F (-5° C) or as cold as -125° degrees F (-87° C). Earthquakes, volcanoes, and meteor impacts continuously change the landscape.

Mars may have had an atmosphere and water similar to Earth at one time in its history. Some evidence remains of frozen water on the cold surface and the existence of a thin, mostly carbon dioxide, atmosphere. Clouds from volcanic activity have been seen swirling above Mars' surface.

Mars is home to the largest volcano in the solar system; Olympus Mons, which towers over the surface of Mars to a height of 15 miles. That is three times the height of Mount Everest! A canyon system so large that the Grand Canyon could fit inside is found on Mars too. This is known as Valles Marinaris. While the planet can be seen with the naked eye from Earth, the invention of the telescope in 1608 allowed scientists to study the many valleys, canyons, and volcanoes along with huge craters and an enormous bulge in the Mars surface called Tharsis.

Moons of Mars

Courtesy NASA/JPL-Caltech
Courtesy NASA/JPL-Caltech

Mars is orbited by two moons known as Phobos and Deimos. They were discovered in August 1877 by Asaph Hall while he was working at the US Naval Observatory. Hall named the moons for the sons of Ares. Ares was the Greek's name for the god of war.

Mars’ moons appear to actually be asteroids much like those in the asteroid belt. They may have come close to Mars and been pulled into its gravity where they began to orbit. They are covered in craters and grooves. Phobos is the larger of the two moons and has a huge crater on its surface. Deimos has a smoother surface and is smaller in size.

More information about the moons of mars can be found here.

Martian dunes
Courtesy NASA/JPL-Caltech

Water on Mars?

Water probably ran on the surface of Mars at one time. Riverbeds have been found along with rocks that appear to have been rounded by running water. There are also signs of erosion found on Mars' surface. No one knows what happened to all of the water. Some of it may exist in the polar regions which have ice caps that change size as Mars goes through its seasons. Some water may exist under the dusty surface or in ground water.

Mars rocks
Courtesy NASA/JPL-Caltech

Life on Mars?

Between 1996 and 2005, NASA (National Aeronautics and Space Administration) was involved in a plan to investigate the possibility of life on Mars.

Little Green Man

It was known as the Mars Surveyor Program and was based on sending spacecraft to orbit, to land and to explore Mars for evidence of life. It was discovered that the soil on Mars has similarities to Earth’s soil. The discovery of water and additional studies of Mars have given hope to the possibility that life did exist on the Red Planet.

The quest for evidence of life on Mars continues with the Mars Exploration Rover Mission. Rovers are car sized propelled laboratories. On July 4, 1997 NASA’s Sojourner Rover landed on the surface of Mars. It was delivered to the surface of Mars in a craft known as Pathfinder. Learn more about Pathfinder and Sojourner here.

Curiosity Rover
Courtesy NASA/JPL-Caltech

Additional rovers have been sent to Mars. The last two, Opportunity which landed on January 25, 2004 and Curiosity, which landed August 6, 2012, continue to explore the surface and send back important information. Read about them here. The rovers are equipped with ten special pieces of equipment to measure minerals in the soil, cameras for taking pictures, drills for getting below the surface, instruments for measuring the atmosphere and a robotic arm to take the place of and do human type activities. The device used for sampling the soil and analyzing it is known as CHIMRA or the Collection and Handling for In-situ Martian Rock Analysis device. Learn more about CHIMRA here.

Courtesy NASA/JPL-Caltech

To date, no life has been identified on Mars. There are plans in the future that will include sending manned missions to Mars.

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