Mars

         Facts about Mars

Mars is sometimes called the red planet because of the brownish-red colour of
its surface. Mars is the second smallest planet in the solar system behind Mercury.
Mars is the fourth planet from the Sun and last of the terrestrial planets and is around
227,940,000 km from the Sun.

The planet is named after Mars, the Roman god of war. It was known to the ancient
Greeks as Ares, their god of war. This is thought to be because of the red colour of the
planet which was also used by other ancient cultures. Chinese astronomers call Mars
the fire star while ancient called it Her Desher meaning the red one.

The tallest mountain known in the solar system is on Mars. Olympus Mons is a 21 km
high and 600 km diameter shield volcano that was formed billions of years ago.
Scientists have found a lot of recent evidence of volcanic lava which suggests Olympus
Mons may still be active.

It is the second highest mountain in the entire solar system, topped only by the Rheasilvia
central peak on the asteroid Vesta, which is 22 km high. When Mars is closest to the
Sun in its orbit the southern hemisphere points toward the Sun and this causes a very
short but fiercely hot summer.

Mars is the only other planet besides Earth that has polar ice caps. The northern cap
is called the Plenum Boreum, with Plenum Australe in the south. Water ice has also
been found under the Martian ice caps.