As much ground as all the Earth’s land. Mars has about as much surface as all the Earth’s land put together, a day forty minutes longer than ours, and seasons, because it is tilted almost as we are.
Across
6,780 km
Surface
144.4 million km²
A day
24 h 40 min
A year
687 Earth days
From the Sun
228 million km
Gravity
0.38 × the Earth’s
Temperature
-65 °C
Moons
2
What you’re seeing
A colour mosaic from the two Viking orbiters, which mapped Mars from 1976 to 1980.
Named places
Olympus Mons: The tallest volcano in the solar system: 22 km high, two and a half times Everest, and as wide across as France. Its slopes are so gentle you would not know you were climbing.
Valles Marineris: A canyon 4,000 km long and up to 7 km deep: as long as the United States is wide, and four times deeper than the Grand Canyon.
Hellas Planitia: The bright patch in the south: an impact basin 2,300 km across whose floor is 7 km below the rim, the lowest ground on Mars. Dust and frost make it shine.
Tharsis Montes: Three volcanoes in a row, Arsia, Pavonis and Ascraeus, each wider than any volcano on Earth, on a bulge that lifts a whole side of the planet.
Elysium Mons: The big volcano of the other hemisphere, 14 km high. InSight landed on the plain below it and heard marsquakes from here.
Argyre Planitia: The second great southern basin, 1,800 km across, ringed by mountains thrown up by the impact that made it.
Utopia Planitia: The largest impact basin known anywhere, buried under smooth northern plains with ice beneath them. Viking 2 landed here in 1976 and China’s Zhurong rover in 2021.
Isidis Planitia: A basin 1,500 km across on the edge between the old southern highlands and the young northern plains. Jezero crater sits on its rim.
Syrtis Major: The dark patch astronomers saw first, in 1659, and used to time the planet’s day. It is a low, wide volcano with little dust on it.
Gale crater: A crater 154 km wide with a mountain in the middle, Mount Sharp, whose layers are a book of Mars’s past. Curiosity has been climbing it since 2012.
Jezero crater: Once a lake: a river flowed in and left a delta you can still see. Perseverance is collecting rocks here for a future trip home.
Meridiani Planum: A plain strewn with tiny iron "blueberries" that only form in water. Opportunity landed for 90 days and drove for 14 years.
Gusev crater: Opportunity’s twin, Spirit, landed here on the other side of the planet, in a crater that was once filled by a river.
Chryse Planitia: Where the first working lander touched down, on 20 July 1976, and sent the first photo from the surface of another planet.
Ares Vallis: An old flood channel. Pathfinder bounced down here on airbags in 1997 with Sojourner, the first rover ever to drive on another world.
Elysium Planitia: A flat, quiet plain chosen so that InSight could sit still and listen. It recorded more than a thousand marsquakes.
Phoenix landing site: Far north, where Phoenix scraped the soil in 2008 and found water ice a few centimetres down.
North polar cap: Water ice 1,000 km across and 3 km thick, with a winter coat of frozen carbon dioxide that comes and goes with the seasons.
South polar cap: Smaller than the north cap and off-centre from the pole. Its dry-ice layer never fully melts, and lakes of salty water may lie under it.
Airy-0: A crater half a kilometre wide that does one job: it marks Mars’s prime meridian, the way Greenwich marks the Earth’s.
USGS Astrogeology, Viking MDIM 2.1 colour mosaic, public domain.