Composition of the
atmosphere (by volume)
|
95.3% carbon dioxide
2.7% nitrogen
1.6% argon
0.13% oxygen
remainder: traces of water vapor, neon, krypton, xenon |
| Average air pressure at
the surface |
6 millibars
(compared to 1013 millibars on Earth) |
Average diameter
of Mars |
6 779 km (about half that
of the Earth)* |
| Average distance from the
Sun: |
227 940 000 km (or 1.52
Astronomical Units, i.e. 1.52 times as far as Earth) |
Martian sidereal day
(i.e., rotation time): |
24 hours, 37 minutes and
22 seconds |
Martian solar day
(i.e., time between two successive noons) |
24 hours, 39 minutes and
35 seconds |
Martian year
(i.e., time to orbit the Sun): |
669.6 Martian solar days
or 687 Earth days (i.e., about 1.9 Earth years) |
| Global average
temperature: |
218 K (-55 °C) |
| Minimum surface
temperature: |
140 K (-133
°C) (temperature of frozen carbon dioxide on high elevations at the
winter pole) |
| Maximum surface
temperature: |
300 K (27 °C) (dark
tropical regions in summer) |
| Surface area: |
about the same as the land
area on Earth |
| Highest mountain: |
Olympus Mons - the largest
mountain in the Solar System rising 24 km above the surrounding plain
(21.2 km above the reference level**). Its base is more than 500 km in
diameter and is rimmed by a cliff 6 km high |
| Largest canyon: |
Valles Marineris - a
canyon 4 000 km long, up to 5.3 km deep**, and up to 20 km wide. |
| Largest impact crater and
deepest point on Mars: |
Hellas Planitia - an
impact crater in the southern hemisphere up to 7.8 km deep** and 2 000
km in diameter
|
| Surface bulge: |
Tharsis - a huge bulge on
the Martian surface that is about 4 000 km across and 10 km high
|
