🌙 Moon
Phobos
A lumpy little moon of Mars, slowly spiralling inwards.
- Size
- 22 km across, 0% as wide as Earth
- Goes round Mars
- every 7.7 hours
- Discovered
- 1877, by Asaph Hall
Did you know?
- It goes around Mars three times a day.
- It is creeping closer to Mars and will break apart or crash in tens of millions of years.
Compare Phobos with EarthSide by side, to scale, in the app
More NASA photos of PhobosStraight from NASA’s image library, in the app
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All of solar system
Mercury
The smallest planet, and the closest to the Sun.
Venus
The hottest planet, hidden under thick clouds.
Earth
Our home, the only world known to have life.
Mars
The red planet, with the tallest volcano in the solar system.
Jupiter
The biggest planet, with a storm larger than Earth.
Saturn
The ringed giant, light enough to float in water.