Could Mars's collision with orbiting asteroid reactivate atmosphere?

Click For Summary

Discussion Overview

The discussion revolves around the hypothetical scenario of a collision between Mars and an orbiting asteroid, exploring the potential consequences for Mars's atmosphere, magnetic field, and geological evolution. Participants consider the implications of such an impact on Mars's ability to support liquid water and a more Earth-like environment.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant suggests that a collision with an asteroid on a collision course could potentially liquify Mars's mantle and re-establish a magnetic field, leading to the possibility of a new atmosphere if sufficient ice from the polar caps thaws.
  • Another participant counters that an impact capable of generating enough energy to melt the mantle would likely require an asteroid the size of a dwarf planet, and questions whether the energy would actually contribute to melting the mantle.
  • A participant draws a parallel between Mars and Earth, speculating that if Mars experienced a significant impact similar to Earth's evolutionary history, it could have developed into a planet with water and a similar atmosphere.
  • Another participant emphasizes the differences between Mars and Earth, noting that Mars's smaller size, lower mass, and greater distance from the Sun would significantly affect its evolution.
  • One participant speculates that if Mars had undergone a massive impact and moved closer to the Sun, it could have become more Earth-like, potentially with its own satellite, while also considering the gravitational influence of Jupiter.
  • A later reply mentions the lower limit for a planet's mass to retain its atmosphere, indicating that insufficient mass could lead to atmospheric loss due to low gravity.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility and implications of a collision with an asteroid, with no consensus reached on the potential outcomes or the likelihood of such scenarios occurring.

Contextual Notes

Participants acknowledge various assumptions regarding the size and energy of the impacting asteroid, as well as the geological and atmospheric conditions on Mars, which remain unresolved.

Matt Todd
Messages
28
Reaction score
0
As I understand it, Mars has 2 asteroids in orbit. One slowly moving away from Mars, the other on an orbital collision course. Could the collision possibly be violent enough to liquify the planets mantle? If so, would Mars re-establish a magnetic field? Is there sufficient ice in the polar caps to thaw and create an atmosphere? Would a newly evolved Mars with protection for it's atmoshere in the form of a magnetic field be a possibility as a result of this impact?
 
Astronomy news on Phys.org
I don't think so. An impact sufficient to put that much energy into Mars would have to have an asteroid the size of a Dwarf planet at least I'm betting. And that's before accounting for where the actual energy from the impact goes, which probably isn't into melting the mantle.
 
Ah okay. You've been very informative today, thanks for all your help Drakkith. So a dwarf planet, something with about the mass of pluto or mercury? It sounds like the impact Earth was involved in during it's evolution. I wonder if Mars would be Earth V.2 If it had undergone a similar impact.
 
Unlikely. The two planets are very very different. Mars is much smaller and less massive and is located further from the Sun. These things affect the planet greatly. But that depends on what you mean by Earth V.2.
 
Fair call. By Earth V.2 I was just meaning a planet with water and a similar atmosphere to our own. Mars actually looks as though there was liquid movent upon the surface at some stage evidenced by the Vallis Marineris (spelling) and also geological activity (Olympus Mons) One feature it does seem to lack is a decent sized moon. I speculate that Mars, if it had undergone a massive, almost terminal impact during it's evolution, and was sent into a closer orbit of the sun, could very well be Earths twin, with it's own similar satelite in orbit. Of course, for liquid water, Mars would have to be close enough to the sun to melt the polar caps, which would interfere with Earths orbit. The other possibility being that Mars was knocked closer to Jupiter, where it's immense gravitational pull on Mars could geologically thaw the planet which would be protected from the solar wind by Jupiters magnetic field. It's all speculation on things that never happened, but I find it fascinating anyway.
 
Yes, if scaled properly, near identical scenarios would probably result in extremely similar results. Your other scenarios are...very unlikely to say the least, and result in a multitude of other issues.
 
There is also a lower limit for the mass of a planet to keep its atmosphere. If the mass of a planet is too small, the corresponding gravity is not strong enough to keep surface gases from slowly diffusing into space (due to the speed of the air molecules).
 

Similar threads

  • · Replies 9 ·
Replies
9
Views
4K
Replies
17
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 65 ·
3
Replies
65
Views
26K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 21 ·
Replies
21
Views
6K
  • · Replies 1 ·
Replies
1
Views
5K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 4 ·
Replies
4
Views
11K