Mars
Mars is the fourth planet from the Sun and the seventh largest in the Solar System. A cold, dusty desert world with a thin atmosphere (mostly CO₂), the planet features extinct volcanoes, deep canyons, polar ice caps, and seasons. Mars has two small moons (Phobos and Deimos), a day just over 24 hours long, and a year lasting about 687 Earth days. It is a prime focus of robotic exploration and studies about past water and habitability.
Source: science.nasa.gov
APODs including "Mars"
Spirit Encounters Soft Ground on Mars
01/06/2009
Will Spirit be able to free itself from soft ground on Mars? The robotic Spirit rover currently rolling across Mars ran into unexpectedly soft ground last month while exploring the red planet. A worry is that the ground is so soft that Spirit won't be able to free itself, will have to stay put and thereafter study what it can from its current position near an unusual martian land feature named Home Plate. Pictured above, the front left wheel appears to be primarily digging itself in when spun, while on the other side, the front right wheel no longer spins and is dragged by the five year old mechanical explorer. In the distance, rocks and rusty dirt fill the alien landscape in front of the distant Husband Hill. NASA continues to study the situation, and engineers and scientists have not yet run out of ideas of how to use Spirit's six wheels. Far across Mars, Spirit's twin Opportunity continues on its two year trek toward Endeavour crater. Free Lecture: An APOD editor will review great space images this Friday in Kalamazoo, Michigan.