What is Mars and how far is it from the Sun?
Mars is the fourth planet from the Sun and a desert world with a rocky sphere surface. Its diameter measures 6,779 kilometers and its surface area equals all dry land on Earth.
Common questions about Mars
Short answers, pulled from the story.
When did Mars form and what was the Late Heavy Bombardment?
Mars formed approximately 4.5 billion years ago from the random accretion of material in the protoplanetary disk. The Late Heavy Bombardment was a period of intense meteorite impacts that left 60% of the planet's surface scarred.
What are the largest geological features on Mars?
Mars features Olympus Mons, the tallest volcano in the Solar System rising over 21 kilometers above the surrounding plains. Valles Marineris is a canyon system stretching 4,000 kilometers that cuts across one-fifth of the planet's circumference.
Did Mars ever have liquid water and where is it now?
Evidence suggests liquid water flowed across Mars billions of years ago before becoming mostly locked in ice. The polar ice caps hold enough water to cover the entire planet to a depth of 35 meters and subsurface ice exists in regions like Utopia Planitia.
What is the composition of the atmosphere on Mars?
The atmosphere of Mars is a thin veil of carbon dioxide making up 96% of its composition. Surface pressure measures only 6 millibars and the sky often appears pink or butterscotch due to suspended iron oxide particles.
When did human exploration of Mars begin and what are current missions?
Human exploration of Mars began in earnest in the 20th century with the first successful flyby by Mariner 4 in 1965. Current missions include the Curiosity and Perseverance rovers which have uncovered evidence of past water activity and potential biosignatures.