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"
A Rusty Sunset on Mars
04/08/1997
On Mars, sunsets can appear salmon pink. The unusual color is partly due to rust: oxidized iron from Martian dust circulating in the Martian atmosphere. Clouds appear in the morning and evening, but usually evaporate in the midday Sun. A day on Mars lasts 24.6 hours - very similar to Earth's, but a Martian year lasts almost twice as long as an Earth year. The above panorama by Mars Pathfinder, shown mirror-inverted, was released last Friday by the Imager team. Mars Pathfinder has now successfully completed all the goals of its planned mission. Nevertheless, the Sagan Memorial Station spent the weekend recharging its batteries, anticipating the possibility of still more productive weeks of exploration ahead.