Mars
Mars is the fourth planet from the Sun and is known as the "Red Planet" for its orange-red appearance. It is a rocky desert planet with a thin atmosphere made mostly of carbon dioxide. Mars has about half Earth's diameter and roughly a third of Earth's surface gravity. The planet hosts dramatic geology, including Olympus Mons, the tallest volcano at 21.9 km high, and Valles Marineris, one of the largest canyons at 4,000 km long. Scientists are intensely interested in Mars because of its geological history and evidence of past water. The possibility of past or present life on Mars remains an active area of scientific investigation.
Sources
- en.wikipedia.org: “Mars is the fourth planet from the Sun. It is also known as the "Red Planet", for its orange-red appearance. Mars is a desert-like rocky planet with a tenuous atmosphere that is primarily carbon dioxide (CO2).”
- en.wikipedia.org: “Its mean diameter, 6,779 km (4,212 mi), is about half the Earth's”
- en.wikipedia.org: “Its surface gravity is roughly a third of Earth's”
- en.wikipedia.org: “the tallest is Olympus Mons, 21.9 km or 13.6 mi tall), as well as one of the largest canyons in the Solar System (Valles Marineris, 4,000 km or 2,500 mi long).”
- en.wikipedia.org: “Because of Mars's geological history, the possibility of past or present life on Mars remains an area of active scientific investigation”