This red planet is the fourth in the Solar System, and actually the second smallest. The now desolate Mars shows signs that it had liquid water and a similar atmosphere to the Earth’s at one time. For these reasons, Mars is one of the most similar planets to Earth in the Solar System!
Numbers to Know
1 Orbit of Sun 686.98 Days
1 Rotation 24 hours 37 mins
Escape Velocity 18,024 km/h (11,200 mph)
Distance From Sun 229 million kilometers (142 million miles)
Max Temperature 36°C (98°F)
Min Temperature -123°C (-190°F)
Atmosphere CO2 95.32%, N2 2.7%, Ar 1.6%, O2 0.13%, CO 0.08%
Diameter 6794 Kilometers (4,222 Miles)
An artists view of Mars and Earth. Try to compare the values above to what you would expect on Earth.
Deep Canyons to Sky High Mountains
Mars has higher mountains and deeper canyons than any other planet in our solar system. Its biggest canyon is Valles Marineris. On Earth this canyon would stretch from New York City to Los Angeles, making the Grand Canyon look tiny. Mars also has the Solar System’s biggest volcano, Olympus Mons. This young volcano is nearly 3 times larger than Mount Everest. Olympus Mons age leads scientists to believe it’s still active, which means it could erupt!
How Did Mars Get its Name?
You may sometimes hear Mars referred to as the “Red Planet” because the planet’s surface appears red. The soil color comes from the high levels of iron oxide minerals in the rock. The planet actually got its name from its color. Roman astronomers saw the red color and thought of blood. For this reason, they named the planet after the Roman god of war.
A hole drilled into Mars by the Curiosity Rover. This image shows Mars’ characteristic red color.
What is the Gravity Like on Mars?
Mars has less mass than the Earth, so it has less gravity too. The gravity is measured to be about 3.7 m/s² while the Earth’s gravity is about 9.8 m/s². This means you would only experience 38% of the gravity you feel on Earth. So if you weighed 100 pounds on the Earth, you would only weigh 38 pounds on Mars. Weighing 62% less would make moving a lot more fun. This is because our muscles and bones have become used to working harder on Earth. With lower gravity, you could jump higher and throw things like baseballs much farther!
Mars excites scientists because the surface shows signs of water erosion. Pictures taken by spacecraft have led scientists to believe that there were once lakes, rivers, and oceans on the planet. This is important because it means there could have been life on Mars. Liquid water is one of the indicators that scientists look for in their search for extraterrestrial life. The planet doesn’t have liquid water on its surface anymore, which decreases the probability of there being life on Mars. This is because the gravity isn’t strong enough to hold onto the gases in the atmosphere. As Mars’ atmosphere slowly depleted into outer space, all the water evaporated. Today, the only water left on the dusty planet is either frozen in the polar caps or underground.
An image of Mars’ surface that shows channels in the rock. Scientists believe these channels were created by rushing water.
The Moons of Mars
Mars has two different moons, Deimos and Phobos. Mars’ moons were both found by an astronomer named Asaph Hall. Hall searched and found the moons with a telescope in August 1877.
The ways scientists have been exploring Mars has changed a lot since the 1960’s. At first, the only way modern explorers could study the planet was with satellites. These satellites would fly close to the surface and take pictures. They would then send these pictures back to Earth for scientists to look at.
Eventually, scientists were able to put spacecraft into orbit around the planet. These types of missions allowed researchers to get even more information on the Mars.
Today, scientists and researchers are able to land spacecraft on the surface of Mars. The most recent spacecraft to land there is the Curiosity Rover. The rover launched from Earth in 2011 and landed in 2012. Since then, the Curiosity Rover has given scientists a lot of insight into the habitability of the planet.
A “selfie” that the Curiosity Rover took of itself. In the background, you can see a dust storm, one example of the harsh conditions that the rover has to survive.