Climate of Mars cold while those in the North are short and warm. It is now thought that ice accumulated when Mars' orbital tilt was very different from what it is now. (The axis the planet spins on has considerable "wobble," meaning its angle changes over time.) A few million years ago, the tilt of the axis of Mars was 45 degrees instead of its present 25 degrees. Its tilt, also called obliquity, varies greatly because its two tiny moons cannot stabilize it like our moon. Many features on Mars, especially in the Ismenius Lacus quadrangle, are thought to contain large amounts of
Mars Global Surveyor shoot pictures of other orbiting bodies, such as other spacecraft and the moons of Mars. In 1998 it imaged what was later called the Phobos monolith, found in MOC Image 55103. After analyzing hundreds of high-resolution pictures of the Martian surface taken by the orbiting Mars Surveyor spacecraft, a team of researchers found that weathering and winds on the planet create landforms, especially sand dunes, remarkably similar to those in some deserts on Earth. Results from the "Mars Global Surveyor" primary mission (1996–2001) were published in the Journal of Geophysical Research by M. Malin and K. Edgett. Some of these