The definition of Mars is the fourth planet from the sun.
Facts About Mars
- The Romans named Mars after their god of war but its nickname is the "Red Planet," named because of its reddish color, caused by the iron oxide in the soil.
- In 1877 Giovanni Schiaparelli noticed a series of strange lines on the surface of the planet which he deemed canali, or canals. He supposed that these lines were waterways or highways built by alien people on Mars. H.G. Wells’ famous novel, The War of the Worlds, detailed an attack on the human race by Martians. In the 1960s the Mariner spacecraft confirmed that Mars was basically a lifeless planet; however, in 1996, scientists examined a meteorite that came from Mars and found microscopic life on it.
- Mars has a diameter of 4220 miles, a bit more than half the size of Earth.
- A day on Mars is approximately 24 hours and 39 ½ minutes. Mars orbits the Sun every 687 Earth days.
- It is a cold planet, reaching -207 degrees F. and rarely getting above freezing (32 degrees F.).
- The poles of Mars are covered in dry ice (carbon dioxide) and the amount of ice varies by season.
- Basalt makes up the outer surface of Mars, due to the volcanic activity in the past.
- The 900 mile diameter core of Mars is mostly solid, made of nickel, iron, and sulfur. The outer crust is basalt. The core produces a very weak magnetic field. There is evidence of water under the surface.
- Mars has the highest mountain in all of the solar system, Olympus Mons. It is an inactive volcano that is 15.5 miles high and 372 miles in diameter.
- Mars has the biggest canyon system in all of the solar system, the Valles Marineris, which is 2500 miles in length and is four miles deep.
- Mars has two small moons. Deimos orbits east to west, and Phobos orbits from west to east. They are not spherical and are most likely asteroids. The moons were discovered in 1877, by Asaph Hall, at the U.S. Naval Observatory.
An example of Mars is the planet that was featured in a radio show narrated by Orson Welles which sent Americans into a panic when the show made it seem that Martians were invading the Earth.