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Terrestrial#4 from Sun

Mars ♂

Mars, the Red Planet, features the tallest mountain and deepest canyon in our solar system. It is the primary target for human space exploration.

Explore 2 moons

About Mars

Atmosphere

Mars has a thin atmosphere composed of about 95 percent carbon dioxide, with nitrogen, argon, and traces of oxygen and water vapor. Surface pressure is less than one percent of Earth's, far too low for liquid water to exist on the surface under normal conditions. However, evidence from orbiters and rovers suggests liquid water once flowed freely on Mars billions of years ago, carving channels and filling ancient lakes.

Notable Features

Mars hosts the largest volcano in the solar system, Olympus Mons, which rises 21.9 km above the surrounding plains and spans 600 km in diameter. Valles Marineris, a system of canyons stretching over 4,000 km, dwarfs the Grand Canyon in every dimension. The planet has polar ice caps composed of water ice and dry ice (frozen carbon dioxide) that grow and shrink with the seasons. Planet-wide dust storms can last for months.

Exploration History

Mars is the most explored planet beyond Earth. NASA's Viking landers made the first successful landing in 1976. The Curiosity rover (active since 2012) discovered that Mars once had conditions suitable for microbial life. Perseverance landed in Jezero Crater in 2021 and has been collecting rock samples for future return to Earth. Ingenuity, the first helicopter to fly on another planet, completed 72 flights before its mission ended in 2024.

Physical Properties

Diameter

6,792 km

Mass (Earth = 1)

0.107

Surface Gravity

3.72 m/s²

Distance from Sun

1.52 AU

Orbital Period

687 days

Rotation Period

24.6 hours

Avg Temperature

-65°C

Escape Velocity

5.03 km/s

Atmosphere Composition

Carbon DioxideNitrogenArgon

How Does Mars Compare to Earth?

Diameter

Mars6,792 km
Earth12,756 km

1.88x smaller than Earth

Mass

Mars0.107x Earth
Earth1.000x

9.35x smaller than Earth

Surface Gravity

Mars3.72 m/s²
Earth9.81 m/s²

2.64x smaller than Earth

Did You Know?

01

Mars has the largest dust storms in the solar system, which can last for months and cover the entire planet.

02

A year on Mars is almost twice as long as a year on Earth (687 Earth days).

03

Mars appears red because of iron oxide (rust) in its soil.

Missions to Mars

MissionYearAgencyStatus
Viking 1 & 21976NASAComplete
Curiosity2012-presentNASAActive
Perseverance2021-presentNASAActive
Ingenuity2021-2024NASAComplete

Mars FAQ

Is there water on Mars?+
Yes. Mars has water ice at both polar caps and subsurface ice deposits at mid-latitudes. In 2018, radar data from ESA's Mars Express suggested a lake of liquid water beneath the south polar ice cap, though this finding is debated. Evidence of ancient rivers, lakes, and even an ocean covers much of the Martian surface.
Why is Mars red?+
Mars appears red because its surface is rich in iron oxide, commonly known as rust. Billions of years ago, iron in Martian rocks was oxidized by water and atmospheric oxygen, coating the surface in fine reddish dust that is also suspended in the atmosphere, giving the sky a butterscotch hue.
Could humans live on Mars?+
Surviving on Mars would require artificial habitats with pressurized atmospheres, radiation shielding, and water extraction from subsurface ice. The thin atmosphere (less than 1 percent of Earth's pressure) cannot support human breathing, and average temperatures around -60 C demand insulated shelters. Space agencies and private companies are actively developing the technology needed.
How big are dust storms on Mars?+
Martian dust storms can grow from regional events to planet-encircling phenomena within weeks. Global dust storms occur roughly every 5.5 Earth years and can blanket the entire planet for months, reducing solar power to rovers by up to 97 percent. The 2018 global storm ended NASA's Opportunity rover mission.

Fun Fact

“Olympus Mons on Mars is the tallest known mountain in the solar system at 21.9 km (13.6 miles) high — nearly 2.5 times the height of Mount Everest.”

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