MARS       PHOBOS        DEIMOS
 
       6794km            22.2km              12.6km              diameter
  6.4219e23kg         1.08e16kg            1.8e15kg              mass
227.940.000km                                                    distance from SUN
                         9378km             23459km              distance from MARS

1. Mars has two moons, PHOBOS and DEIMOS
2. The surface of Mars
3. The temperature of Mars and the seasons with snow and ice
4. Clouds air and wind
5. Spacecraft visits in 1965 1976, maybe in 1996 and 1998
6. Human habitation on Mars
   1. temperature variation from 150k (-220F) to 295K (70F)
   2. in the past there was clearly water on the surface of mars, there may even have been oceans
   3. the average pressure on the surface of mars is only about 7 millibar (less than 1% of earth's)
   4. mars has permanent ice caps at both poles
   5. mars has no global magnetic fields
   6. mars has a very thin atmosphere
   7. the favorite planet of sciencefiction writers

• Phobos is doomed
  In greek mythology Phobos is a daughter of Mars and Venus. Phobos is greek for "fear" (the root of "phobia").
  Jonathan Swift described the moons of Mars giving their exact size and speeds of rotation. He did this more than 100 years before either moon was discovered.
  Phobos is closer to its primary than any other moon in the solar system, less than 6000km above the surface of Mars. It is also one of the smallest moons in the solar system. Phobos is doomed because forces are pulling her toward Mars. In less than 11 million years she will break up into a ring or crash onto the surface of Mars.
  Deimos is composed of carbonrich rock like asteroids and ice. It is heavily cratered. It is probably perturbed by Jupiter into orbits that allowed him to be captured by Mars.
  The most prominent feature on Phobos is the large crater named Stickney. The groves and streaks on the surface of Phobos were probably caused by Stickney. Phobos and Deimos may someday be useful as "space stations" for intermedite stops to and from Mars.

• Deimos, the smallest moon in the solar system
  Deimos is a son of Mars and Venus. He is discovered in 1877 by Hall and photographed by the Viking 1 in 1977.
  Deimos is composed of carbonrich rock like asteroids and ice. It is heavily cratered. It is probably perturbed by Jupiter into orbits that allowed him to be captured by Mars.

• The surface of Mars
  The Olympus Mons is the largest mountain in the Solar System rising 24 km above the surrounding plain, her base is more than 500km in diameter and is rimmed by a cliff of 6km high.
  Tharsis is a huge bulge on the surface of Mars that is about 4000km across and 10km high.
  Valles Marineris is a system of canyons 4000km long and 2 to 7km deep.
  Hellas Planitia is an impact crater in the southern hemisphere over 6km deep and 2000km in diameter. There are also much younger rift valleys, ridges, hills and plains.

• Spacecraft visits
  The first spacecraft visit to Mars was the Mariner 4 in 1965. Several others followed like the Mariner 6 and 7 and the two Viking Landers in 1976. The Vikings probes found no evidence of life on Mars, but they sampled only two isolated locations and so the possibility that life once existed on Mars is still there. Missions to Mars have been attempted since Viking.
  On the evening of august 21 in 1993 the Mars Observer lost contact with earth. Every day without a signal was more and more a message that the mission had been lost. a rupture of the tubing probably caused the spacecraft to spin at a rapid rate, perhaps the solar arrays would no longer be pointed at the sun? It is also possible that the spacecraft simply flew past Mars and is now continuing in its orbit around the sun.
  Heroic activities focused on recovering the spacecraft continued for two month with no positive results. Five large radio astronomy antennas in de US, CANADA, ENGLAND and PUERTO RICO were used over a period of six months to try to hear the small signal from the beacon. If it could be heard, it would attest to the fact that the spacecraft was intact and could still receive commands. But the beacon was not heard. will the observer still be alife?
  The media converged on the Jet Propulsion Laboratory for an explanation of what had gone wrong with the mission, which was on the verge of its most important engeneering event, that on going into orbit aroud Mars.

• There may even have been oceans:
  it seems that this was only briefly and very long ago. the age of the erosion channels is estimated at about 4 billion years. Valles Marineris was not created by running water, it was formed by the stretching and cracking of the crust associated with the creation of the Tharsis Bulge.