The common definition of matter is anything that has mass and volume (occupies space). For example, a car would be said to be made of matter, as it has mass and volume (occupies space). The observation that matter occupies space goes back to antiquity.
The Radius of Mars is 3,389.5 km (About half of the radius of the Earth). Its circumference is 21,344 km (Not a big surprise, this is also about half of the circumference of the Earth). The volume of Mars is 1.63116 X 10 11 km 3 and the mass of Mars is 6.4169 x 10 23 kg. Although Mars is smaller than Earth its surface area (38% of earth) Is Almost identical to earth LAND space (Since there are no oceans on Mars). A common hoax is about the moon and Mars being equal in size. The hoax started back in 2003 when in august 27th Mars was in opposition to earth (Minimal distance) of about 55 Million KM.
Mars has two relatively small natural moons, Phobos (about 22 km (14 mi) in diameter) and Deimos (about 12 km (7.5 mi) in diameter), which orbit close to the planet. Asteroid capture is a long-favored theory, but their origin remains uncertain.