# Up to what distance from the Moon does the Moon's gravity hold its exosphere before it is being cast away by solar wind?

Up to how far from the Moon is the Moon's exosphere gravitationally bound to it? For the Earth's exosphere it is 120,000 mi (190,000 km) or half the Moon's distance from the Earth, beyond that the Earth's exosphere is cast away by solar wind, the atoms reach escape velocity. What's the equivalent value for the Moon's gas atoms?

The Moon's exosphere is discussed in the following, but there doesn't seem to be an answer in them:

The slim, bright crescent, known as the Lunar Horizon Glow (LHG) was glimpsed several times during Apollo missions. This picture was taken with the Clementine spacecraft, when the sun was behind the moon. The white area on the edge of the moon is the LHG, and the bright dot at the top is the planet Venus. (Image credit: NASA)

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• @uhoh Thanks for the edit/expansion. Nov 8, 2021 at 12:06
• Keep in mind this is a statistical situation. The probability that the energy in the "solar wind" causes atmospheric particles to reach escape velocity varies in a smoothish curve with altitude. Nov 8, 2021 at 16:00