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Astronomy: Mars
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Mars is the last from the inner planets of the Sun and last of the solid planets close to the moon. Mars' neighbours are our own Earth and Jupiter although between Mars and Jupiter an asteroid belt orbits the Sun. There are theories that Mars in the past had a neighbouring planet which was somehow destroyed. Mars has been named after the god of war for its red colour and is only half of Earth's size. There has been found evidence that once liquid water flowed on the planet. But in the process of cooling down, billion years ago, our neighbour has become an icy world with 2 polar ice caps. A Martian day last for 24,6 hours. One year at Mars/ an orbit around the Sun takes 686,9 Earth days for Mars. |
 The surface can hardly be visible in case of a global dust storm which last for long periods of time.  This false color global map of energetic neutrons shows presumed concentrations of near surface water ice (blue shades). Ice was found as well at the poles as at lower latitudes. The melting of near surface ice could be responsible for the formation of martian gullies. Picture taken by Mars Odyssey.  Long traces of melted water ice at the base of these mountains (martian gullies). This picture is about 16 kilometers high. < JPG image 1188 X 800 pixels > |
Giant vulcanosMars has four gigantic vulcanos that are much larger than the largest vulcano on Earth. The largest vulcano Olympus Mons is 27 km high and was discovered by the orbiting Mariner 9 in 1971.The Mariner was observing Mars for almost one year, but Mars revealed little because of a long during global dust storm. When the storm was slowly fading away four big shapes appeared, the giant vulcanos amazed scientists. At first you might be puzzeled why a planet half the size of Earth can harvest such big vulcanos, but this can be explained by the relatively inactive inner state of the planet. Mars is less active than Earth; it has less vulcano activity so it misses the smoothing effect from erosion and has more craters. And Earth has the movements of the oceanic plates, which in a period of some million years shrinks Earth's mountains and vulcanos. On Earth vulcanos grow just like on Mars, but on Mars they do not shrink, because the planet has no plate tectonics. |
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The Grand Canyon of MarsWith the last dust falling down on the surface, around the equator a giant canyon became visable. The 180 km wide canyon Valles Marineris spans a region as long as the United States. It was named after the Mariner 9 sattelite.It is believed that the origin of Valles Marineris lies in the four vulcanos. In the process of growing and swelling from the vulcanos they pulled the crust of Mars open, forming a very big canyon. The moons Phobos and DeimosMars has two tiny moons named Phobos and Deimos. They were both discovered in 1877 by Asaph Hall from the United States. In Greek mythology, Deimos and Phobos are both one of the sons of Ares (Mars) and Aphrodite (Venus). "Deimos" is Greek for "panic". "Phobos" is Greek for "fear" (the root of "phobia").Phobos is the most remarkable moon orbiting Mars three times in a Martian day. Seen from Mars, Phobos looks as half the size of our Moon and sets in the East after only four and a half hours. It is believed that these small non-circular satellites (Phobos 27 km (17 miles) and Deimos 15 km (9 miles at maximum) originate from the asteroid belt between Jupiter and Mars. The two asteroids came too close to Mars and could not escape from its gravitial pull. video of Phobos taken by Mariner 9 (MPEG, 104Kb, 10 sec) video of Deimos taken by Viking (MPEG, 476Kb, 7 sec) Seeing MarsMars is one of the best visible objects in the sky to be observed by an amateur astronomer. At its closest approach to Earth, it is only 56 million km away. It is one of the brightest objects in the sky, outshining most stars.A small amateur telescope can show the phase of Mars; after on average 780 days Mars, Earth and the Sun line up. 
Related subjects>> Mars seen from Earth>> Mars Odyssey >> Mariner >> Viking >> Two scientists reinterpret Viking results: Peroxide Life on Mars (pdf) |
 A detailled close up from Mars' Vulcanos Certholus < JPG image 1689 x 933 pixels >  Stunning picture of Valles Marineris. The ripped crust is linked to the giant vulcanos on the opposite side of Mars. < JPG image 1552 x 1552 pixels >  Mars seen from the Hubble Space Telescope on 26 August 2003, 1 day before the maximum conjunction of Mars' and Earth's orbits in over 50.000 years. |
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