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"
Mars: A Mist In Mariner Valley
17/10/1997
An icy mist and late afternoon clouds cover much of this section of Valles Marineris on Mars. The Valles Marineris or Mariner Valley is a huge canyon system about 2,000 miles long and up to 5 miles deep. This test image was produced using data from Mars Global Surveyor's wide angle cameras viewing the canyon from a distance of 360-600 miles. Color was synthesized using images recorded through blue and red filters. Mission controllers have recently raised the spacecraft's aerobraking orbit to study the unexpected motion of one of the Surveyor's solar panels.