<h2>Mercury</h2>
<blockquote>
<p>MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) data show that most of Mercury's surface consists of lava plains. However, no volcanoes (mountains built by eruptions) have been found to date. This is unexpected because planets and moons with lava plains also have volcanoes. We conducted a new search and found two good candidate volcanoes. We cannot be sure that they are volcanoes based on MESSENGER data. <strong>Nevertheless, the observation that volcanoes on Mercury are rare is important itself. It means most eruptions on Mercury were somehow different from those that made volcanoes elsewhere in the solar system. We suggest that most eruptions on Mercury were too large and rapid, meaning that lava spread out to form plains, rather than building volcanoes.</strong> We suggest that eruptions small enough to build volcanoes might have occurred in Mercury's later history, when it was cooler and less able to generate magma. Impact craters may have helped later magma to erupt by opening fractures in Mercury's crust. We suggest that BepiColombo, the next spacecraft mission to Mercury, should target impact craters to find more volcanoes and return better observations of our candidates.</p>
<p><sub> Wright, J., Rothery, D. A., Balme, M. R., &amp; Conway, S. J. (2018). Constructional volcanic edifices on Mercury: Candidates and hypotheses of formation. Journal of Geophysical Research: Planets, 123, 952– 971. <a href="https://doi.org/10.1002/2017JE005450" rel="nofollow noreferrer">https://doi.org/10.1002/2017JE005450</a></sub></p>
</blockquote>
<p>Also see: <a href="https://mobile.arc.nasa.gov/public/iexplore/missions/pages/yss/may.html" rel="nofollow noreferrer">https://mobile.arc.nasa.gov/public/iexplore/missions/pages/yss/may.html</a></p>
<h2>Moon</h2>
<p>From <a href="https://en.wikipedia.org/wiki/Volcanism_on_the_Moon" rel="nofollow noreferrer">Wikipedia</a>:</p>
<blockquote>
<p><strong>A number of domes and cones are present on the Moon, but such features likely formed differently than those on Earth. Because gravity on the Moon is only one sixth of that on Earth, lunar volcanism is capable of throwing ejecta much further, leaving little to pile up near the vent. Instead of a volcanic cone, such lunar eruptions should form a broad, thin layer around the ven</strong>t. On Earth, lava domes form from very thick, pasty lavas. Basaltic lavas are more liquid and tend to form broad, flat lava flows. On the Moon, most of the domes and cones appear to be made of basalts. As a result, they are unlikely to have formed like Earth domes from thick, non-basaltic lavas. Instead, the lunar domes and cones may mark places where the erupted basalts were just barely molten.</p>
</blockquote>

CC BY-SA 4.0
2021-10-26T03:05:53.703Z
2021-10-26T03:05:53.703Z
Nilay Ghosh
<p>There are numerous examples of multi-kilometre tall mountains such as <a href="https://en.wikipedia.org/wiki/Maat_Mons" rel="nofollow noreferrer">Maat mons</a> on Venus, <a href="https://en.wikipedia.org/wiki/Mauna_Kea" rel="nofollow noreferrer">Mauna Kea</a> on Earth, the <a href="https://en.wikipedia.org/wiki/Tharsis_Montes" rel="nofollow noreferrer">Tharsis</a> volcanoes on Mars. <strong>We don't find similar such examples of volcanic edifices anywhere else. Why?</strong></p>
<p><a href="https://en.wikipedia.org/wiki/Mons_R%C3%BCmker" rel="nofollow noreferrer">Mons Rümker</a> is the the closest thing to that on the moon, but it is a rarity, and quite modest in height anyway.</p>
<p>Mercury doesn't have anything like that, all you see is <a href="https://en.wikipedia.org/wiki/Picasso_(crater)" rel="nofollow noreferrer">pits</a>, <a href="https://en.wikipedia.org/wiki/Hollows_(Mercury)" rel="nofollow noreferrer">hollows</a>, lava floods, etc.</p>
<p>I am aware that <a href="https://en.wikipedia.org/wiki/Mountains_of_Io" rel="nofollow noreferrer">Io has a lot of relief</a>, but these are not really volcanic edifices, but some sort of crustal deformation.</p>
<p>is it heat budget? Io has a lot more than any terrestrial planet. Surface gravity? Mercury's matches that of Mars.</p>
<p>Edit: I've removed cryovolcanic worlds from the title since I understand that cryolavas may have a harder time to build such structures, although I recall <a href="https://en.wikipedia.org/wiki/Sotra_Patera" rel="nofollow noreferrer">Sotra patera</a> as an example of a <a href="https://www.youtube.com/watch?v=5BrejYODYA0" rel="nofollow noreferrer">modest cone</a> found on Titan.</p>

CC BY-SA 4.0
2021-10-25T22:11:28.977Z
Mercury appears to be different to the other planets. It is thought to be the remnant core of a planet that was impacted by a planetesimal that stripped the crust & mantle from the original planet [Mercury](https://en.wikipedia.org/wiki/Mercury_(planet)). Thus, very little, if any volcanic activity.
Fred
CC BY-SA 4.0
2021-10-25T22:33:42.430Z
There are many [types of volcanoes](https://www.nationalgeographic.org/article/plate-tectonics-volcanic-activity/). Factors affecting their sizes are: the minerals in the magma & the viscosity  of the molten rock, the amount of magma in the magma chamber & the pressure within the chamber - the higher the pressure the greater the force of the eruption, the higher the ejected material can go, the taller a volcano can be.
Fred
CC BY-SA 4.0
2021-10-26T07:45:45.380Z
See also [Why is Olympus Mons the largest volcano in the whole solar system?](https://earthscience.stackexchange.com/q/20242/18081), which has some explanations and links about the maximum height of mountains on different planetary bodies.
Jean-Marie Prival
<planetary-science><geology><terrestrial-planets><volcanism>
Why do Venus, Earth, and Mars have tall volcanoes, but the Moon, Mercury, and Io don't?
we'll see
# Why do Venus, Earth, and Mars have tall volcanoes, but the Moon, Mercury, and Io don't?

(Asked by: username_0 on 2021-10-25)

There are numerous examples of multi-kilometre tall mountains such as [Maat mons](https://en.wikipedia.org/wiki/Maat_Mons) on Venus, [Mauna Kea](https://en.wikipedia.org/wiki/Mauna_Kea) on Earth, the [Tharsis](https://en.wikipedia.org/wiki/Tharsis_Montes) volcanoes on Mars. **We don't find similar such examples of volcanic edifices anywhere else. Why?**

[Mons Rümker](https://en.wikipedia.org/wiki/Mons_R%C3%BCmker) is the the closest thing to that on the moon, but it is a rarity, and quite modest in height anyway.

Mercury doesn't have anything like that, all you see is [pits](https://en.wikipedia.org/wiki/Picasso_(crater)), [hollows](https://en.wikipedia.org/wiki/Hollows_(Mercury)), lava floods, etc.

I am aware that [Io has a lot of relief](https://en.wikipedia.org/wiki/Mountains_of_Io), but these are not really volcanic edifices, but some sort of crustal deformation.

is it heat budget? Io has a lot more than any terrestrial planet. Surface gravity? Mercury's matches that of Mars.

Edit: I've removed cryovolcanic worlds from the title since I understand that cryolavas may have a harder time to build such structures, although I recall [Sotra patera](https://en.wikipedia.org/wiki/Sotra_Patera) as an example of a [modest cone](https://www.youtube.com/watch?v=5BrejYODYA0) found on Titan.

**Tags:** planetary-science, geology, terrestrial-planets, volcanism
> **Comments:**
> **username_1**: Mercury appears to be different to the other planets. It is thought to be the remnant core of a planet that was impacted by a planetesimal that stripped the crust & mantle from the original planet [Mercury](https://en.wikipedia.org/wiki/Mercury_(planet)). Thus, very little, if any volcanic activity.  
> **username_1**: There are many [types of volcanoes](https://www.nationalgeographic.org/article/plate-tectonics-volcanic-activity/). Factors affecting their sizes are: the minerals in the magma & the viscosity  of the molten rock, the amount of magma in the magma chamber & the pressure within the chamber - the higher the pressure the greater the force of the eruption, the higher the ejected material can go, the taller a volcano can be.  
> **username_2**: See also [Why is Olympus Mons the largest volcano in the whole solar system?](https://earthscience.stackexchange.com/q/20242/18081), which has some explanations and links about the maximum height of mountains on different planetary bodies.  

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## 1 answers

### Answer by username_3 on 2021-10-26. Score: 1

## Mercury

> MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) data show that most of Mercury's surface consists of lava plains. However, no volcanoes (mountains built by eruptions) have been found to date. This is unexpected because planets and moons with lava plains also have volcanoes. We conducted a new search and found two good candidate volcanoes. We cannot be sure that they are volcanoes based on MESSENGER data. **Nevertheless, the observation that volcanoes on Mercury are rare is important itself. It means most eruptions on Mercury were somehow different from those that made volcanoes elsewhere in the solar system. We suggest that most eruptions on Mercury were too large and rapid, meaning that lava spread out to form plains, rather than building volcanoes.** We suggest that eruptions small enough to build volcanoes might have occurred in Mercury's later history, when it was cooler and less able to generate magma. Impact craters may have helped later magma to erupt by opening fractures in Mercury's crust. We suggest that BepiColombo, the next spacecraft mission to Mercury, should target impact craters to find more volcanoes and return better observations of our candidates.
>
> Wright, J., Rothery, D. A., Balme, M. R., & Conway, S. J. (2018). Constructional volcanic edifices on Mercury: Candidates and hypotheses of formation. Journal of Geophysical Research: Planets, 123, 952– 971. <https://doi.org/10.1002/2017JE005450>

Also see: <https://mobile.arc.nasa.gov/public/iexplore/missions/pages/yss/may.html>

## Moon

From [Wikipedia](https://en.wikipedia.org/wiki/Volcanism_on_the_Moon):

> **A number of domes and cones are present on the Moon, but such features likely formed differently than those on Earth. Because gravity on the Moon is only one sixth of that on Earth, lunar volcanism is capable of throwing ejecta much further, leaving little to pile up near the vent. Instead of a volcanic cone, such lunar eruptions should form a broad, thin layer around the ven**t. On Earth, lava domes form from very thick, pasty lavas. Basaltic lavas are more liquid and tend to form broad, flat lava flows. On the Moon, most of the domes and cones appear to be made of basalts. As a result, they are unlikely to have formed like Earth domes from thick, non-basaltic lavas. Instead, the lunar domes and cones may mark places where the erupted basalts were just barely molten.


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