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: Cydonia Close-Up
16/04/1998
The Mars Global Surveyor spacecraft has returned another close-up of the Cydonia region on Mars. Orbiting over clear Martian skies at a range of about 200 miles, the Mars Orbiter Camera looked down on features known as the "City" on Mars and produced a high resolution image covering a swath around 1.5 by 15 miles at a pixel size of about 8.2 feet. This cropped portion of the processed image shows an area approximately 1.5 miles wide. Heavily weathered hills and pocked surfaces suggest the erosion of layers of the ancient Martian crust.