Sunday, December 2, 2012

Mars (Planet)

Mars is a planet of the Solar System, the nearest to the Earth, occupying the fourth position in distance from the Sun at 229 million km away from it. With a diameter of 4,200 miles (6,800 km), Mars is about half the size of the Earth. It has ice caps, a tilted axis, and an atmosphere composed mostly of carbon dioxide, but has no magnetic field, which means that perhaps Mars has no metallic core. Its surface is marked by dry channels, canyons, and craters, suggesting that, may be, water might have flowed on its surface a long time ago.