A photo of Mars from NASA's Viking spacecraft, which launched in 1975.
Credit: The Viking Project/NASA
The distance from Earth to Mars varies a lot, because Earth’s orbit around the sun is might smaller than Mars’ orbit. Earth is the third planet from the sun, and Mars is the fourth.
Imagine two cars on a racetrack, and one is always on the inside while the other is on the outside. Earth is on the inside track, and so it gets around more quickly. Sometimes it’s close to Mars, when it’s making a pass, and other times it’s far away, at the other side of the track.
The minimum distance from the Earth to Mars is about 54.6 million kilometers. The farthest apart they can be is about 401 million km. The average distance is about 225 million km.
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