<p>It is certainly possible for rocks from Earth to be ejected and impact - and survive impact - on Mars.  However, without doing specific isotopic analysis to determine the origin, one cannot simply look at a meteorite and determine its source body.  No rovers that we have now have the capability to measure these isotopes.</p>

<p>With that overview, it is much harder for a rock from Earth to land on Mars: Going outwards in the solar system is harder to do than going inwards for ejected material.  I don't know of any really recent work done on this, but a model by Melosh &amp; Tonks (1993; <a href="https://ui.adsabs.harvard.edu/abs/1993Metic..28Q.398M/abstract" rel="noreferrer">abstract here</a>) found that only 5% of material ejected from Earth will hit Mars, but more from Mars hit Earth.  <a href="https://science.sciencemag.org/content/271/5254/1387" rel="noreferrer">Gladman et al. (1996)</a> also looked at the Mars ejection question and found that about 7.5% of ejecta from Mars will make it to Earth, but I don't see them doing a corresponding analysis for Earth-to-Mars.</p>

<p>Most dynamic work that I know of has modeled stuff coming to Earth because it's stuff on Earth that we can really analyze and have a chance of determining is origin.</p>

CC BY-SA 4.0
2020-06-01T00:23:36.730Z
2020-06-01T00:23:36.730Z
Stuart Robbins
<p>Well if no one is going to answer this I will. The answer is we don't know for sure. We speculate that there should be earth rocks on mars but until we 'see' one and analyze it we will not know for sure.  The comments here all point to this answer.</p>
<p><a href="https://www.slashgear.com/mars-hit-with-thousands-of-earth-rocks-possibly-containing-life-following-asteroid-impact-11308540/" rel="noreferrer">Mars hit with thousands of Earth rocks possibly containing life following asteroid impacte</a> talks about the Chicxulub impact and how it probably spread rocks to all the terrestrial planets in our solar system and the moons of all the planets.</p>
<blockquote>
<p>The statement comes from Penn State University researchers who have calculated the approximate number of rocks from our planet large enough to possibly carry life that have made their way into space over the past few billion years.</p>
<p>Said the paper’s lead author Rachel Worth: “We find that rock capable of carrying life has likely transferred from both Earth and Mars to all of the terrestrial planets in the solar system and Jupiter. Any missions to search for life on Titan or the moons of Jupiter will have to consider whether biological material is of independent origin, or another branch in Earth’s family tree.”</p>
</blockquote>
<p>The article cites its source as The BBC's <a href="http://www.bbc.co.uk/news/science-environment-25201572" rel="noreferrer">Dinosaur asteroid 'sent life to Mars'</a> which cites a 2013 paper published in Astrobiology <em>Seeding Life on the Moons of the Outer Planets via Lithopanspermia</em>:</p>
<blockquote>
<p>The asteroid that wiped out the dinosaurs may have catapulted life to Mars and the moons of Jupiter, US researchers say.</p>
<p>They calculated how many Earth rocks big enough to shelter life were ejected by asteroids in the last 3.5bn years.</p>
<p>The Chicxulub impact was strong enough to fire chunks of debris all the way to Europa, <a href="https://www.liebertpub.com/doi/full/10.1089/ast.2013.1028" rel="noreferrer">they write in Astrobiology</a>.</p>
<p>Thousands of potentially life-bearing rocks also made it to Mars, which may once have been habitable, they add.</p>
<p>&quot;We find that rock capable of carrying life has likely transferred from both Earth and Mars to all of the terrestrial planets in the solar system and Jupiter,&quot; says lead author Rachel Worth, of Penn State University.</p>
</blockquote>

CC BY-SA 4.0
2020-06-01T00:25:05.283Z
yes, I can.. I couldn't find the actual paper but the site I selected referred to a study performed at Penn State.
Natsfan
CC BY-SA 4.0
2020-05-31T23:18:54.863Z
2020-06-01T00:31:15.170Z
2020-06-17T09:47:40.653Z
Natsfan
<p>Certain meteorites found on Earth have been established to come from Mars: a giant impact ejected rocks from Mars, these rocks traveled through interplanetary space, and went through the Earth's atmosphere without completely burning up. </p>

<p>Might it be possible to find a meteorite on Mars that comes from Earth from the same kind of mechanism? </p>

<p>Earth's gravity is stronger than Mars', so I guess you would need a bigger impact to send debris into interplanetary space. And the atmosphere is thicker on Earth, so the impacting body would need to be even bigger for enough of it to touch the ground. And you also need to give the rocks more energy so that they can go outwards in the Sun's gravitational well. So I'm guessing that impacts that might be violent enough are rarer for the Earth than they are for Mars.</p>

<p>Might it be possible for there to be Earth meteorites on Mars? And if so, is there any chance that we might stumble upon one?</p>

CC BY-SA 4.0
2020-05-29T14:28:54.743Z
Also, getting from Earth to Mars is uphill from the Sun's point of view.
badjohn
CC BY-SA 4.0
2020-05-29T14:30:09.630Z
@badjohn but from the point of view of orbital mechanics, there's a lot of energy required to reduce or increase orbital   radius.
Carl Witthoft
CC BY-SA 4.0
2020-05-29T14:31:42.730Z
Yes, I am not sure whether it is significant but it seemed worth considering at least.
badjohn
CC BY-SA 4.0
2020-05-29T16:58:07.157Z
I think someone has done this calculation; I can't remember where, though.  As I recall the result was that some quantity of material from earth has impacted nearly every sizeable body in the Solar System; we could find an Earth rock on Titan.
antlersoft
CC BY-SA 4.0
2020-05-29T17:13:40.897Z
Given how little of the martian surface we can access *and* analyze to the required level of detail, it's hard to see how we could stumble upon one.  They would be rare, assuming they exist.
StephenG - Help Ukraine
CC BY-SA 4.0
2020-05-31T18:38:56.070Z
Surely some tiny bit of earthly rock dust has by now managed to hitch a ride to Mars on one of the many entry vehicles and landers We've sent to the planet.
Wayfaring Stranger
CC BY-SA 4.0
2020-06-01T17:19:02.997Z
Gravity is less important than you might think.  Escape velocity matters, but it also increases the velocity of impact.  An object only needs 11 km/s to escape, but can hit Earth up to 70 km/s.   Earth's atmosphere is probably a bigger obstacle, as the air slows potential escaping objects down.  You'd need a very large impact to generate large enough ejecta that could get through Earth's atmosphere and escape.
userLTK
CC BY-SA 4.0
2020-06-01T17:20:00.750Z
@badjohn  In a sense, it's an up-hill both ways situation.
userLTK
CC BY-SA 4.0
2020-06-02T09:14:50.187Z
@userLTK I am not saying that it is the dominant factor but just that it may be a factor.  To get to Mars, an object needs to gain gravitational potential energy.
badjohn
<solar-system><mars><meteorite>
Are there Earth rocks on Mars?
usernumber
# Are there Earth rocks on Mars?

(Asked by: username_0 on 2020-05-29)

Certain meteorites found on Earth have been established to come from Mars: a giant impact ejected rocks from Mars, these rocks traveled through interplanetary space, and went through the Earth's atmosphere without completely burning up.

Might it be possible to find a meteorite on Mars that comes from Earth from the same kind of mechanism?

Earth's gravity is stronger than Mars', so I guess you would need a bigger impact to send debris into interplanetary space. And the atmosphere is thicker on Earth, so the impacting body would need to be even bigger for enough of it to touch the ground. And you also need to give the rocks more energy so that they can go outwards in the Sun's gravitational well. So I'm guessing that impacts that might be violent enough are rarer for the Earth than they are for Mars.

Might it be possible for there to be Earth meteorites on Mars? And if so, is there any chance that we might stumble upon one?

**Tags:** solar-system, mars, meteorite
> **Comments:**
> **username_1**: Also, getting from Earth to Mars is uphill from the Sun's point of view.  
> **username_2**: @badjohn but from the point of view of orbital mechanics, there's a lot of energy required to reduce or increase orbital   radius.  
> **username_1**: Yes, I am not sure whether it is significant but it seemed worth considering at least.  
> **username_3**: I think someone has done this calculation; I can't remember where, though.  As I recall the result was that some quantity of material from earth has impacted nearly every sizeable body in the Solar System; we could find an Earth rock on Titan.  
> **username_4**: Given how little of the martian surface we can access *and* analyze to the required level of detail, it's hard to see how we could stumble upon one.  They would be rare, assuming they exist.  
> **username_5**: Surely some tiny bit of earthly rock dust has by now managed to hitch a ride to Mars on one of the many entry vehicles and landers We've sent to the planet.  
> **username_6**: Gravity is less important than you might think.  Escape velocity matters, but it also increases the velocity of impact.  An object only needs 11 km/s to escape, but can hit Earth up to 70 km/s.   Earth's atmosphere is probably a bigger obstacle, as the air slows potential escaping objects down.  You'd need a very large impact to generate large enough ejecta that could get through Earth's atmosphere and escape.  
> **username_6**: @badjohn  In a sense, it's an up-hill both ways situation.  
> **username_1**: @userLTK I am not saying that it is the dominant factor but just that it may be a factor.  To get to Mars, an object needs to gain gravitational potential energy.  

---

## 2 answers

### Answer by username_8 on 2020-05-31. Score: 13 | Accepted answer

Well if no one is going to answer this I will. The answer is we don't know for sure. We speculate that there should be earth rocks on mars but until we 'see' one and analyze it we will not know for sure. The comments here all point to this answer.

[Mars hit with thousands of Earth rocks possibly containing life following asteroid impacte](https://www.slashgear.com/mars-hit-with-thousands-of-earth-rocks-possibly-containing-life-following-asteroid-impact-11308540/) talks about the Chicxulub impact and how it probably spread rocks to all the terrestrial planets in our solar system and the moons of all the planets.

> The statement comes from Penn State University researchers who have calculated the approximate number of rocks from our planet large enough to possibly carry life that have made their way into space over the past few billion years.
>
> Said the paper’s lead author Rachel Worth: “We find that rock capable of carrying life has likely transferred from both Earth and Mars to all of the terrestrial planets in the solar system and Jupiter. Any missions to search for life on Titan or the moons of Jupiter will have to consider whether biological material is of independent origin, or another branch in Earth’s family tree.”

The article cites its source as The BBC's [Dinosaur asteroid 'sent life to Mars'](http://www.bbc.co.uk/news/science-environment-25201572) which cites a 2013 paper published in Astrobiology *Seeding Life on the Moons of the Outer Planets via Lithopanspermia*:

> The asteroid that wiped out the dinosaurs may have catapulted life to Mars and the moons of Jupiter, US researchers say.
>
> They calculated how many Earth rocks big enough to shelter life were ejected by asteroids in the last 3.5bn years.
>
> The Chicxulub impact was strong enough to fire chunks of debris all the way to Europa, [they write in Astrobiology](https://www.liebertpub.com/doi/full/10.1089/ast.2013.1028).
>
> Thousands of potentially life-bearing rocks also made it to Mars, which may once have been habitable, they add.
>
> "We find that rock capable of carrying life has likely transferred from both Earth and Mars to all of the terrestrial planets in the solar system and Jupiter," says lead author Rachel Worth, of Penn State University.

> **Comments:**
> **username_8**: yes, I can.. I couldn't find the actual paper but the site I selected referred to a study performed at Penn State.  

---

### Answer by username_7 on 2020-06-01. Score: 6

It is certainly possible for rocks from Earth to be ejected and impact - and survive impact - on Mars. However, without doing specific isotopic analysis to determine the origin, one cannot simply look at a meteorite and determine its source body. No rovers that we have now have the capability to measure these isotopes.

With that overview, it is much harder for a rock from Earth to land on Mars: Going outwards in the solar system is harder to do than going inwards for ejected material. I don't know of any really recent work done on this, but a model by Melosh & Tonks (1993; [abstract here](https://ui.adsabs.harvard.edu/abs/1993Metic..28Q.398M/abstract)) found that only 5% of material ejected from Earth will hit Mars, but more from Mars hit Earth. [Gladman et al. (1996)](https://science.sciencemag.org/content/271/5254/1387) also looked at the Mars ejection question and found that about 7.5% of ejecta from Mars will make it to Earth, but I don't see them doing a corresponding analysis for Earth-to-Mars.

Most dynamic work that I know of has modeled stuff coming to Earth because it's stuff on Earth that we can really analyze and have a chance of determining is origin.


---

