A full globe view of Mars


Mars is the fourth planet from the Sun, and the seventh largest. It’s the only planet we know of inhabited entirely by robots.

All About Mars

This composite image, from NASA Galileo and Mars Global Survey orbiters, of Earth and Mars was created to allow viewers to gain a better understanding of the relative sizes of the two planets.

Mars is 53% smaller than Earth.

The bright red-orange surface of Mars as seen from space.

Mars is 1.52 AU from the Sun. Earth = 1.

Sundial on Perseverance rover on Mars.

A Martian day is a little longer than Earth's; a Mars year is almost two Earth years.

U.S. flag visible on Viking lander with Martian terrain on horizon

Mars' surface has been altered by volcanoes, impacts, winds, and crustal movement.

Illustration of astronaut repelling down the side of Valles Marineris.

Mars' atmosphere is mostly carbon dioxide, argon, and nitrogen.

Roundish, reddish moon with massive crater on one end.

Phobos and Deimos are small compared to the planet.

Rusty-red Mars with a haze of white clouds and a white north polar cap.

Mars has no rings.

Perseverance Selfie

The first success was NASA's Mariner 4 flyby in 1965,

Image of ancient riverbed on Mars.

Missions are determining Mars' past and future potential for life.

Perseverance spots Santa Cruz on Mars

Iron minerals in the Martian soil oxidize, or rust, causing the soil and atmosphere to look red.

Planet Mars Overview

Mars is no place for the faint-hearted. It’s dry, rocky, and bitter cold. The fourth planet from the Sun, Mars is one of Earth's two closest planetary neighbors (Venus is the other). Mars is one of the easiest planets to spot in the night sky – it looks like a bright red point of light.

Despite being inhospitable to humans, robotic explorers – like NASA's Perseverance rover – are serving as pathfinders to eventually get humans to the surface of the Red Planet.

Eyes on the Solar System lets you explore the planets, their moons, asteroids, comets and the spacecraft exploring them from 1950 to 2050. Ride with the Curiosity Rover as it lands on Mars or fly by Pluto with the New Horizons spacecraft all from the comfort of your home computer.

Pop Culture

No other planet has captured our collective imagination quite like Mars.

In the late 1800s when people first observed the canal-like features on Mars' surface, many speculated that an intelligent alien species resided there. This led to numerous stories about Martians, some of whom invade Earth, like in the 1938 radio drama, "The War of the Worlds." According to an enduring urban legend, many listeners believed the story to be real news coverage of an invasion, causing widespread panic.

Countless stories since have taken place on Mars or explored the possibilities of its Martian inhabitants. Movies like "Total Recall" (1990 and 2012) take us to a terraformed Mars and a struggling colony running out of air. A Martian colony and Earth have a prickly relationship in "The Expanse" television series and novels.

And in the 2014 novel and its 2015 movie adaptation, "The Martian," botanist Mark Watney is stranded alone on the planet and struggles to survive until a rescue mission can retrieve him.

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