Mars compared to Earth

The Red Planet: a thin carbon-dioxide atmosphere, the tallest volcano in the solar system, and dry riverbeds.

How big is Mars compared to Earth?

Mars is roughly half as wide as Earth.

Mars orbits on average about one and a half times as far from the Sun as Earth does.

Mars takes about 1.9 Earth years to go once round the Sun.

Mars turns round once in about 25 hours; Earth takes about 24 hours.

Mars has roughly one ninth the mass of Earth.

Mars has roughly one seventh the volume of Earth.

On Mars you would weigh roughly two fifths of what you weigh on Earth.

Mars runs from −153 to 20 °C. Earth runs from −89.2 to 56.7 °C.

Sidereal rotation: 24.62 hours. Solar day (“sol”): 24.66 hours — the gap is tiny because, like Earth, Mars’s year is long compared with its day.

What it is like: Rocky, covered in red iron-oxide dust (rust), with the tallest volcano in the solar system and ancient dry riverbeds.
Its weather: Thin CO2 atmosphere, planet-wide dust storms, average −65 °C.
The machines we sent: NASA’s Perseverance rover has been exploring Jezero crater since 2021, searching for signs of past life.

The numbers

Across	6,779 km
Distance from the Sun, on average	1.524 AU · 227.9 million km · sunlight takes 12 minutes 40 seconds
Once round its orbit	1.881 Earth years
Sunrise to sunrise	24.66 hours
How big it looks	3.5 to 26 arcseconds, depending on how far away it is — the full Moon is about 1,800
Temperature	−65 °C (from −153 to 20)
Also found there	carbon dioxide, water, rock