Longest dimension27,000 m
15,000Taylor Swifts
57.4 billionBlue light wavelengths
Irregularly shaped: ~27 × 22 × 18 km
Photo from Wikimedia Commons
Phobos
Mars's larger, doomed moon/Moons
Phobos is the larger and closer of Mars's two moons. It is a small, irregularly shaped body covered in craters, with the prominent Stickney crater spanning nearly half its width. Phobos orbits closer to its planet than any other known moon and is slowly spiralling inward; in roughly 50 million years it will either crash into Mars or break apart into a ring.
Measurements
Intermediate dimension22,000 m
44 millionTardigrade body lengths
6.1 quintillionAlpha particles
Shortest dimension18,000 m
50,000Hip widths
12.6 billionthsSaturn orbit radii
295Hockey rink lengths
Mass10.7 quadrillion kg
142 trillionKeanu Reeveses
7.8 quadrillionCostco rotisserie chickens
395 trillionDalmatian dogs
Mean orbital speed2,138 m/s
7,127Roombas
2,138Shopping cart rolls
Orbital period27,554 s
27.6 millionCamera flash durations
2,876100m dash records
5.5 millionHousefly wingbeats
About 7.66 hours, faster than Mars's rotation