Planets · #93 biggest of 1,014
How big is Phobos (moon)?
23 km
Phobos (moon) measures 23 km. That's about 2.55 Mount Everests lined up end to end.
By the numbers
- That's 23 km, or about 14 miles.
- It's about 13,294 times taller than an average adult (1.7 m).
- Roughly 68 Eiffel Towers could line up across it.
- Walking nonstop, you'd need about 4.48 hours to travel its length.
- Out of all 1,014 things in this collection, it ranks #93 by size.
Size comparison
How Phobos (moon) stacks up against things of a similar size. Tap any bar to explore it.
Bang Na Expressway
54 km
Lake Pontchartrain Causeway
38.442 km
Hangzhou Bay Bridge
35.673 km
Jiaozhou Bay Bridge
26.707 km
Phobos (moon)
22.6 km
neutron star
20 km
Deimos (moon)
12.3 km
Halley's Comet nucleus
11 km
Mariana Trench (depth)
10.994 km
Bars use a logarithmic scale so everything fits — real differences are even more extreme!
Fun fact
Standing beside it, an average person (1.7 m tall) would reach only about 0.008% of its height.
More in Planets
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