<p>In addition to the chemical composition and age of these meteorites mentioned in @Gerald's answer, there is another clue in martian meteorites that makes it very unlikely that these meteorites might come from another body: as the rock gets partially melted, re-solidified and ejected into space, small bubbles of gas get trapped in it. These gases trapped in the meteorite have been analyzed and compared to the composition of the martian atmosphere measured by the Viking lander, and they are strikingly similar.</p>

CC BY-SA 4.0
2020-10-07T09:10:10.317Z
2020-10-07T09:10:10.317Z
usernumber
<p>Mars is the only planet providing rocks with a similar chemical composition and age. So the origin of the meteorite is evident.</p>

<p>This doesn't mean, that it's absolutely waterproof. There might have existed protoplanets similar to Mars 4 billion years ago, which since then have been swallowed by Jupiter, the Sun, or have been ejected out of the solar system. But this would be much of coincidence without leaving convincing evidence. (<a href="http://arxiv.org/pdf/1306.0975.pdf">Here a paper about a couple of simulations</a>.)</p>

CC BY-SA 3.0
2014-05-06T11:07:21.910Z
2014-05-06T11:07:21.910Z
Gerald
<p>There are many documented cases of meteorites being reported as <em>from Mars</em>.</p>

<p><a href="http://en.wikipedia.org/wiki/Allan_Hills_84001">http://en.wikipedia.org/wiki/Allan_Hills_84001</a></p>

<p>While I can understand that it's possible to know if a rock originated as a meteorite. What I don't understand is how scientists can say it came from Mars with certainty.</p>

<p>How can they verify such a claim, and differentiate between a rock that is <em>similar</em> to one from Mars to one that <em>really</em> is from Mars.</p>

CC BY-SA 3.0
2014-05-06T03:19:47.007Z
perhaps they check out the areas in which Meteor Showers were seen,then by chemical compositions they can ensure that the rocks are from mars may be.
Praveen Kadambari
CC BY-SA 3.0
2014-10-21T14:17:05.530Z
As a sidenote, if you go to the Smithsonian Museum of Natural History in Washington, D.C., you can actually touch a fragment of a meteorite believed to be from Mars.
NeutronStar
<mars><meteorite>
How do scientists know that a rock found on Earth came from Mars?
Reactgular
# How do scientists know that a rock found on Earth came from Mars?

(Asked by: username_0 on 2014-05-06)

There are many documented cases of meteorites being reported as *from Mars*.

<http://en.wikipedia.org/wiki/Allan_Hills_84001>

While I can understand that it's possible to know if a rock originated as a meteorite. What I don't understand is how scientists can say it came from Mars with certainty.

How can they verify such a claim, and differentiate between a rock that is *similar* to one from Mars to one that *really* is from Mars.

**Tags:** mars, meteorite
> **Comments:**
> **username_1**: perhaps they check out the areas in which Meteor Showers were seen,then by chemical compositions they can ensure that the rocks are from mars may be.  
> **username_2**: As a sidenote, if you go to the Smithsonian Museum of Natural History in Washington, D.C., you can actually touch a fragment of a meteorite believed to be from Mars.  

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## 2 answers

### Answer by username_4 on 2014-05-06. Score: 7 | Accepted answer

Mars is the only planet providing rocks with a similar chemical composition and age. So the origin of the meteorite is evident.

This doesn't mean, that it's absolutely waterproof. There might have existed protoplanets similar to Mars 4 billion years ago, which since then have been swallowed by Jupiter, the Sun, or have been ejected out of the solar system. But this would be much of coincidence without leaving convincing evidence. ([Here a paper about a couple of simulations](http://arxiv.org/pdf/1306.0975.pdf).)


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### Answer by username_3 on 2020-10-07. Score: 3

In addition to the chemical composition and age of these meteorites mentioned in @Gerald's answer, there is another clue in martian meteorites that makes it very unlikely that these meteorites might come from another body: as the rock gets partially melted, re-solidified and ejected into space, small bubbles of gas get trapped in it. These gases trapped in the meteorite have been analyzed and compared to the composition of the martian atmosphere measured by the Viking lander, and they are strikingly similar.


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