What are Phobos and Deimos?

Phobos and Deimos are Martian months. It is one of the smallest known months in the solar system, with an average diameter of 22.2 km and 12.6. Phobos orbits extremely close to the Martian surface with an altitude of only 6000 km (3728 miles). This is compared to the fact that it is said, an international space station that orbits around 350 km (217 miles) above the Earth's surface, but it is usually a month of any, known. PHOBOS orbits Mars every seven and a half hours, compare with an international space station orbiting the country every hour and a half.

The Martian surface can be observed by Phobos, which passes through the sun and covers about 20% of the disk. Deimos, a similar size to Phobos, but significantly distant, orbiting 23,460 km (14,577 million) above the Martian surface, appears only as a black dot passing through the sun, which it regularly does. Both transit events were observed by the Rovers on the Mars surface.

Phobos and Deimos are not massive enough to be in hydrostatic balance,ie spherical. Phobos has such an irregular shape and deep in Mars gravity well that gravity on its surface differs by up to 450%. Its escape speed is only 11 m/s - it is too high to jump off the surface, because the fastest human jumps are only about 2 m/s - but weak missile or even a curled spring. You can even set the ramp and drive the car fast enough to achieve escape speed if you can supply oxygen for your internal combustion engine.

Phobos is covered with odd grooves and a large crater named Stickney, after his discoverer's wife, ASAPH HALL, head of astronomer in the US naval observatory at the end of the 19th century. The detection of Martian months required a telescope 66 cm/26-in, the largest in the world at that time. So far, the paintings of the highest resolution of Phobos and Deimos have taken by Mars Global Surveyor, who entered the Marťan orbit in 1997 and with which the contact was lost in 2006.