Olympus Mons (Mars)
21.2 km (13.17 mi)
Peak height above the Mars datum (MOLA areoid)
The tallest volcano in the Solar System. Its real slopes are far gentler; only the height counts here. Height: about 21.2 km above the Mars reference level, 2.4 Everests.
Published
How big is that?
21.2 km is 2.4 times Mount Everest and 0.61% of the Moon.
Olympus Mons is the 15th smallest of the 39 Cosmic Scale objects, and the 25th largest of the 109 objects across all three SizeItUp games.
Size comparison
To scale, smallest to largest: Olympus Mons in orange beside the Cosmic Scale objects nearest in size, in teal.
| Object | Size | vs Olympus Mons |
|---|---|---|
| Mount EverestEarth's highest mountain, measured above sea level. | 8,848.86 m tall | 42% of the size |
| Halley's Comet (Nucleus)The icy core of the famous comet, measured along its longest side. | 15 km long | 71% of the size |
| Olympus Mons (Mars) | 21.2 km tall | – |
| Phobos (Moon of Mars)A lumpy little moon. Measured along its longest side. | 26 km long | 1.2× bigger |
| Grand Canyon (Earth)Arizona's canyon, seen from above and measured along the Colorado River. | 446 km long | 21× bigger |
In other units
| Metres | 21,200 |
|---|---|
| Kilometres | 21.2 |
| Feet | 69,550 |
| Yards | 23,180 |
| Miles | 13.17 |
How it's measured
Peak height above the Mars datum (MOLA areoid). NASA Mars-GRAM user guide.
Sources
- ntrs.nasa.gov: The peak of Olympus Mons is 21.2 km above the MOLA areoid.
Checked against the source on .
Could you have guessed it by eye?
Olympus Mons is one of the objects in Cosmic Scale, a daily size comparison game: you stretch a shape to the size you think is right beside one you know.