Mars Facts

Mars Planet Profile

View on Maps:
Distance from Sun: 141.6 million mi
Radius: 2,106 mi
Polar Diameter: 6,752 km
Orbital Period: 6.42 x 10^23 kg (10.7% Earth)
Mass: 6.39 × 10^23 kg 0.107 M⊕
Surface pressure: -153 to 20 °C
Moons: (2) Phobos, Deimos
First Recorded: 2nd Millennium BCE by Egyptian astronomers

As the fourth planet from the Sun, Mars is also the last of what are called the “terrestrial planets”. Mars is named after the Roman god of war, who was a mythological figure.

Mars has also been called the Red Planet due to its reddish-brown color on the surface. It is the second smallest planet in the Solar System, with Mercury being the smallest.

Life on Mars

In a majority of the 19th century, people believed that there was life on Mars. The main reason for this was due to part error and part imaginative creation by the 1877 astronomer Giovanni Schiaparelli.

He looked through his telescope to see the surface of Mars and noticed that there were lines on it that he thought were created by living creatures. He called these lines “canalis” that others then called “canals,” and from that point on there was a lot of conjecture, stories, and science fiction written about life on Mars.

It wasn’t until more powerful telescopes were developed that astronomers realized that the lines were part of a natural process that created an optical illusion.

Over the years there has been many stories wrapped around potential life on Mars. From little green men, to Martians invading Earth, radio, television, comic books, movies, and novels were created.

It is thought that this constant interest in Mars helped to continue interest in space exploration of the future.

Mission to Mars

By the 1970’s, the Viking mission to Mars allowed experiments to be conducted on Martian soil in hopes that they could detect microorganisms.

Scientists continued to speculate that if conditions were right for life to exist beneath the planet’s surface, Mars may have a water source that has yet to be discovered.

Thanks to the Mars Rovers that have spent many years covering the planet’s surface and sending back data, we are finding out more than we ever knew about this planet. Future planetary missions may include the Mars Science Laboratory and ExoMars missions.

Atmosphere on Mars

The atmosphere of Mars is quite similar to that of Venus. It has a main component (95%) of carbon dioxide and Venus is 97%.

The difference between the two planets is that runaway greenhouse effect on Venus allows temperatures over 480 degrees C, whereas Mars never goes higher than 20 degrees C. The variation is also credited to the density of the two atmospheres.

Mars has a thin atmosphere and Venus has a thick atmosphere. Extensive research has gone into the idea that the atmosphere on Mars might also have an impact on the presence of liquid water.

The polar caps of Mars has been found to have frozen water, and other evidence is showing that liquid water may exist below the surface of the planet. It is also thought that at one time, Mars may have had an atmosphere strong enough to support water on the planet’s surface.

 Mars surface

The surface of Mars is divided into two feature types which are divided by the hemisphere of the planet. The northern hemisphere is pretty smooth with only a few craters, but the southern hemisphere has highlands that are a lot more cratered.

Mars has the largest known crater in the Solar System, Valles Marineris, and the largest known volcano in the Solar System, Olympus Mons. The crater is large enough to stretch from the U.S. West Coast to East Coast.

The most distinctive feature on Mars is the “channels,” which have the appearance of being made by running water.

Facts about Mars

  • Of all of the missions to Mars, only 16 of the 39 missions have been successful.
  • Meteorites that have landed on Earth have been found to be from Mars.
  • Mars has some of the largest dust storms of any planet in the Solar System.
  • When you look at the Sun from Mars it is about half the size that you would see looking at it on Earth.
  • Other than Earth, scientists believe that Mars may be the planet most hospitable to life.
  • Other than Earth, Mars is the only planet that has polar ice caps.
  • Mars has seasons, however, due to the axis tilt, they last twice as long as those on Earth.
  • Mars doesn’t have a magnetic field.

Mars Quiz

  • Astronomy for Kids