Mars the Fourth Planet from the Sun

The average distance between Mars and the sun is 142 million miles orbiting at 14.5 miles per second.The diameter of the planet is 4,220 miles its axis tilts at 25 degrees the length of the Martian year is 687 earth days the length of its day is 24 hours and 37 minutes. Its gravity is very weak being only .375 that of the earth. The average temperature is a chilly -81 degrees F .The atmosphere is made up mostly of carbon dioxide and water vapour .Mars also has two moons orbiting around it.The Martian atmosphere is very thin and is almost totally composed of carbon dioxide. This thin atmosphere exposes the planet to a higher number of meteor impacts than would occur on earth as there is no atmosphere to burn up these incoming objects through friction.

The diameter of Mars is roughly half the diameter of the earths. Just like earth mars has valleys, deserts volcanoes and polar ice caps. One significant geomorphologic feature on mars is Olympus Mons this is a volcano and the largest known mountain in the solar system. Mars also has one of the largest canyons in the solar system called Valles Marineris.Mars appears to have polar ice caps but theses are made up of frozen carbon dioxide and not water ice. Further analysis of these ice caps shows that they contain massive amounts of hydrogen below the surface. This has led astronomers to speculate that the water on Mars is locked below the surface of the planet.

Mars has two moons Phobos and Deimos astronomers speculate that both moons were captured by the gravitational pull of Mars .Phobos is 7 times larger than Deimos.Phobos orbits Mars at a faster rate than Mars rotates around its axis . From the surface of Mars Phobos appears to set twice each day.In greek mythology Phobos means is the son of Ares or Mars and Aphrodite or Venus. Phobos hass an irregular shape and orbits at a distance of around 9377 km from the Martian surface .Phobos has a lot of craters on its surface .Demios is the smaller of Mars’s moons it is also named after a character representing alarm and fear in greek mythology.Demios has a circular orbit and it orbiting much further out than Phobos .Demios orbits at a distance of 23436 km from the martian surface .

In terms of human exploration Mars is a favourite having been guest to dozens of spacecraft from earth. These spacecraft come from many different countries. These include the Europeans, the United States, Japan and Russia. The first successful flyby of mars was conducted in 1965 by a spacecraft called, mariner 4.Mars currently has 5 spacecraft three orbiting and two on the surface .Mars Odyssey, Mars Express and Mars Reconnaissance Obiter are in orbit around Mars Exploration Rover Opportunity and Mars Science Laboratory Curiosity are on the surface. The first spacecraft sent to Mars launched by NASA was Mariner 4 it did a one off fly by of Mars and took pictures using a TV camera. The pictures it took disappointed many believers in alien civilisations existing on Mars as the pictures showed a barren and desolate planet with a surface pockmarked by craters caused by asteroid strikes. Mars does not have the thick atmosphere necessary to buffer against large objects entering its atmosphere. The next space craft sent by NASA was called Mariner 9 this spacecraft was designed to orbit Mars . In addition to orbiting it was also tasked with mapping out the entire surface of Mars.

The next spacecraft sent to Mars was the Viking missions which included both an Obiter and a Lander. The Lander was designed to touch down on the planets surface and take soil samples .These samples turned out nothing new but reaffirmed the position of Mars being a dead and inhospitable world. The Viking obiter however which was tasked with continuing to map the surface of Mars took a picture of a unique geological feature that looked like a human face which became famous. This face turned out to be a collection of hills and not evidence of some advance alien civilisation.