Mars is the fourth planet from the Sun and is commonly known as the Red Planet because of its reddish surface. The planet gets this color from iron oxide (rust) that covers much of its soil and rocks.

Mars has long fascinated scientists and astronomers because it is one of the most Earth-like planets in the solar system. Evidence suggests that billions of years ago Mars may have had rivers, lakes, and possibly oceans, raising questions about whether life might once have existed there.

Today, Mars is a cold desert world with a thin atmosphere, but it continues to be one of the most studied planets by space missions.

Mars Planet Quick Facts (4th Planet)

Feature	Information
Planet Type	Rocky (Terrestrial)
Distance from Sun	228 million km
Diameter	6,779 km
Length of Day	24.6 hours
Length of Year	687 Earth days
Moons	2 (Phobos & Deimos)
Average Temperature	−60°C
Surface Gravity	38% of Earth

Size of Mars

Mars has a diameter of about 6,779 kilometers (4,212 miles).

Although much smaller than Earth, Mars is still larger than Mercury.

Planet	Diameter
Mercury	4,879 km
Venus	12,104 km
Earth	12,742 km
Mars	6,779 km

Mars has only about 38% of Earth’s gravity, meaning objects weigh much less there.

Why Mars Is Called the Red Planet

The surface of Mars is covered with iron-rich dust and rocks.

When iron reacts with oxygen, it forms iron oxide, which has a reddish color similar to rust on Earth.

This reddish surface gives Mars its famous nickname: the Red Planet.

Surface of Mars

Mars has some of the most impressive geological features in the solar system.

Olympus Mons

Mars is home to Olympus Mons, the largest volcano in the solar system.
It is about 22 kilometers tall, nearly three times the height of Mount Everest.

Valles Marineris

Mars also contains Valles Marineris, a massive canyon system stretching over 4,000 kilometers.

These features indicate that Mars once had strong geological activity.

Mars Atmosphere

Mars has a very thin atmosphere.

It is made mostly of:

• Carbon dioxide (95%)
• Nitrogen
• Argon

Because the atmosphere is so thin, Mars cannot trap heat effectively. As a result, the planet experiences cold temperatures and frequent dust storms.

Temperature on Mars

Mars is much colder than Earth.

Time	Temperature
Average Temperature	−60°C
Winter Poles	−125°C
Summer Equator	20°C

Despite the cold climate, the planet occasionally experiences warmer temperatures near the equator.

Moons of Mars

Mars has two small moons:

Phobos

Phobos is the larger moon and orbits very close to Mars.

Deimos

Deimos is smaller and orbits farther away.

Scientists believe these moons may have formed from asteroid material captured by Mars’ gravity.

Exploration of Mars

Mars has been explored by numerous spacecraft.

Viking Missions

NASA’s Viking 1 and Viking 2 missions in the 1970s were the first to successfully land on Mars.

Mars Rovers

Several robotic rovers have explored the planet, including:

• Spirit
• Opportunity
• Curiosity
• Perseverance

These missions study the planet’s geology and search for signs of past microbial life.

Could Life Exist on Mars?

Scientists believe Mars once had liquid water on its surface billions of years ago.

Recent discoveries show evidence of:

• ancient river channels
• lakebeds
• underground ice

These findings suggest Mars may once have had conditions suitable for microbial life.

Future missions aim to collect samples that could provide more answers.

Interesting Facts About Mars

• Mars has the largest volcano in the solar system.
• A day on Mars is almost the same length as a day on Earth.
• Mars has massive dust storms that can cover the entire planet.
• The gravity on Mars is much weaker than Earth’s.
• Scientists are studying Mars as a possible future destination for human exploration.

Other Planets in the Solar System

Mars is just one of the eight planets orbiting the Sun.

Explore the others:

• Mercury – the smallest planet
• Venus – the hottest planet
• Earth – the only known planet with life
• Jupiter – the largest planet
• Saturn – famous for its rings
• Uranus – the tilted ice giant
• Neptune – the farthest planet

Also read the full guide: Solar System Planets

FAQ About Mars