<p>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?</p>
<p>The Moon's exosphere is discussed in the following, but there doesn't seem to be an answer in them:</p>
<ul>
<li>Wikipedia: <a href="https://en.wikipedia.org/wiki/Exosphere#Moon%27s_exosphere" rel="nofollow noreferrer">Moon's exosphere</a></li>
<li>Space.com <a href="https://www.space.com/18067-moon-atmosphere.html" rel="nofollow noreferrer">Atmosphere of the Moon</a></li>
<li>Space.com <a href="https://www.space.com/17138-helium-moon-atmosphere-lunar-discovery.html" rel="nofollow noreferrer">Helium Spotted in Moon's Wispy Atmosphere</a></li>
<li>Wikipedia <a href="https://en.wikipedia.org/wiki/Atmosphere_of_the_Moon" rel="nofollow noreferrer">Atmosphere of the Moon</a></li>
</ul>
<hr />
<p><a href="https://i.sstatic.net/waAeA.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/waAeA.jpg" alt="The slim, bright crescent, known as the Lunar Horizon Glow (LHG) was glimpsed several times during Apollo missions." /></a></p>
<blockquote>
<p>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)</p>
</blockquote>
<p><a href="https://www.space.com/18067-moon-atmosphere.html" rel="nofollow noreferrer">Source</a></p>

CC BY-SA 4.0
2021-11-08T16:00:23.883Z
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.
Carl Witthoft
CC BY-SA 4.0
2024-10-08T06:14:59.463Z
There are some calculations shown here: https://www.ias.ac.in/article/fulltext/jess/114/06/0637-0644
Nilay Ghosh
<the-moon><planetary-atmosphere><planetary-science>
Up to what distance from the Moon does the Moon's gravity hold its exosphere before it is being cast away by solar wind?
LoveForChrist
# Up to what distance from the Moon does the Moon's gravity hold its exosphere before it is being cast away by solar wind?

(Asked by: username_0 on 2021-11-08)

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:

* Wikipedia: [Moon's exosphere](https://en.wikipedia.org/wiki/Exosphere#Moon%27s_exosphere)
* Space.com [Atmosphere of the Moon](https://www.space.com/18067-moon-atmosphere.html)
* Space.com [Helium Spotted in Moon's Wispy Atmosphere](https://www.space.com/17138-helium-moon-atmosphere-lunar-discovery.html)
* Wikipedia [Atmosphere of the Moon](https://en.wikipedia.org/wiki/Atmosphere_of_the_Moon)

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[![The slim, bright crescent, known as the Lunar Horizon Glow (LHG) was glimpsed several times during Apollo missions.](https://i.sstatic.net/waAeA.jpg)](https://i.sstatic.net/waAeA.jpg)

> 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)

[Source](https://www.space.com/18067-moon-atmosphere.html)

**Tags:** the-moon, planetary-atmosphere, planetary-science
> **Comments:**
> **username_1**: 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.  
> **username_2**: There are some calculations shown here: https://www.ias.ac.in/article/fulltext/jess/114/06/0637-0644  

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## 0 answers

