Mercury

Mars

Mars is a dusty, cold, desert world with a very thin atmosphere. There is strong evidence Mars was – billions of years ago – wetter and warmer, with a thicker atmosphere.

10 Need-to-Know Things About Mars

  • SMALL PLANET

    If the Sun were as tall as a typical front door, Earth would be the size of a dime, and Mars would be about as big as an aspirin tablet.

  • FOURTH ROCK

    Mars orbits our Sun, a star. Mars is the fourth planet from the Sun at an average distance of about 228 million km (142 million miles) or 1.52 AU.

  • LONGER DAYS

    One day on Mars takes a little over 24 hours. Mars makes a complete orbit around the Sun (a year in Martian time) in 687 Earth days.

  • RUGGED TERRAIN

    Mars is a rocky planet. Its solid surface has been altered by volcanoes, impacts, winds, crustal movement and chemical reactions.

  • BRING A SPACESUIT

    Mars has a thin atmosphere made up mostly of carbon dioxide (CO2), argon (Ar), nitrogen (N2), and a small amount of oxygen and water vapor.

  • TWO MOONS

    Mars has two moons named Phobos and Deimos.

  • RINGLESS

    There are no rings around Mars.

  • MANY MISSIONS

    Several missions have visited this planet, from flybys and orbiters to rovers on the surface.The first true Mars mission success was the Mariner 4 flyby in 1965.

  • TOUGH PLACE FOR LIFE

    At this time, Mars' surface cannot support life as we know it. Current missions are determining Mars' past and future potential for life.

  • RUSTY PLANET

    Mars is known as the Red Planet because iron minerals in the Martian soil oxidize, or rust, causing the soil and atmosphere to look red.

Exploration

No planet beyond Earth has been studied as intensely as Mars. Recorded observations of Mars date as far back as the era of ancient Egypt over 4,000 years ago, when they charted the planet's movements in the sky. Today, NASA has a fleet of robotic spacecraft study Mars from all angles.

The human on the moon On the ground: NASA's next-generation Perseverance rover – the largest, most advanced rover NASA has sent to another world – touched down on Mars on Feb. 18, 2021. Two other NASA spacecraft already are at work on the surface. NASA's Curiosity rover is exploring Mount Sharp in Gale Crater. NASA's InSight, a stationary lander, is probing the interior of Mars from a site on a flat smooth plain called Elysium Planitia.

In the air: The Ingenuity helicopter flew to Mars attached to the belly of Perseverance. On April 19, 2021, Ingenuity became the first aircraft in history to make a powered, controlled flight on another planet.

In orbit: NASA has three spacecraft in orbit: Mars Reconnaissance Orbiter, Mars Odyssey, and MAVEN.

International missions: The Hope orbiter from the United Arab Emirates arrived at Mars on Feb. 9, 2021. China’s Tianwen-1 mission arrived on Feb. 10, 2021, and it includes an orbiter, a lander, and a rover. In May 2021, China became the second nation to ever land successfully on Mars when its Zhurong Mars rover touched down. ESA manages the ExoMars Trace Gas Orbiter and Mars Express missions. India's first Red Planet spacecraft – the Mars Orbiter Mission (MOM) – has been orbiting Mars since 2014.