A meteorite from Mars found on Earth?

[N3ptune]

We see that often on the internet, on TV, scientists found a Martian meteorite on earth. Each time I ear that I say to myself: How in the world is it possible to tell that a particular rock found on earth came from Mars... and not from anywhere else from outer space or simply from earth.

An asteroid needs to hit Mars in order to throw rock into space, then the fragments are sent to earth, on a giant pile of earth rocks!

What do you think about that? (If I had to to explained this to an average 10 years old)

Thanks.

[barkis]

Millions of years ago, Mars was very active as a Planet. There oceans, and active Volcanoes.
The largest Volcano/ Mountain in the Solar system is the Mars Olympus Mons. it is a Shield  Volcano, and reaches a height of 26 miles.
Much debris would be launcHed into space, from Volcanic Activity, as well as violent Meteoric Impacts, sufficient in energy to Throw Martian
Rocks out beyond the planets gravitational pull, which is about 40% that of the Earth, so quite strong.
These rocks would drift in space for thousands, if not millions of years before falling into the Earths gravity influence, so not
surprising they do turn up on our planet. Over 100 have been Identified as from Mars.
Look up Allan Hills 84001, a famous one Designated ALH84001.
 

[Alien 13]

As above, there are probably some earth rocks on Mars too.

Alan

[barkis]

7 minutes ago, Alien 13 said:

As above, there are probably some earth rocks on Mars too.

Alan

Yes that is interesting. I wonder if on future manned expeditions, should it ever happen of course, they find Earth material on Mars,
examination would turn up any Microbic Earth life on the samples.
They did find a Mars Rock on Earth which they believed has Martian Microbes on it, but I don't think it proved a positive find in the end.

[D4N]

Yes it is one of the problems with searching for life on mars, even though it is millions of kilometres away microbes could have been taken there from earth either by meteors or space vehicles.  There is even the possibility that life was seeded to Earth in this way although this does seem unlikely.

[acey]

1 hour ago, N3ptune said:

We see that often on the internet, on TV, scientists found a Martian meteorite on earth. Each time I ear that I say to myself: How in the world is it possible to tell that a particular rock found on earth came from Mars... and not from anywhere else from outer space or simply from earth.

The Viking spacecraft landed on Mars in 1976 and sampled the atmosphere there.  A few years later the same proportions of gasses - a "signature" of Martian origin - was found trapped in microscopic bubbles in meteorite EETA 79001 from Antarctica. It was found there because rocks on top of ice fields are very conspicuous and can only have come from above.

There are other ways of identifying Martian meteorites from their chemical composition, e.g. the proportions of different oxygen isotopes, and more than a hundred have been identified.

[DRT]

53 minutes ago, D4N said:

Yes it is one of the problems with searching for life on mars, even though it is millions of kilometres away microbes could have been taken there from earth either by meteors or space vehicles.  There is even the possibility that life was seeded to Earth in this way although this does seem unlikely.

Why do you think that is unlikely? (on meteors rather than space vehicles )

[D4N]

It's the part about life evolving somewhere else in the solar system and being brought here that I find unlikely, it seems more likely to have formed here.

[DRT]

1 minute ago, D4N said:

It's the part about life evolving somewhere else in the solar system and being brought here that I find unlikely, it seems more likely to have formed here.

I think it is even more unlikely that life only formed in one place. When the Earth had its first signs of life it was a very different place to what we know today. Those same (or similar) conditions will have existed in many places in our solar system and others. It is the concept of life forms hitching a ride on deeply frozen objects that I find hard to get my head around but if bits of Martian atmosphere trapped in rocks and ice can make it to the Arctic ice shelf why couldn't a little basic life form do that too?

 

[N3ptune]

Ok ok, thanks for the the opinion on the subject, it's interesting, it's special. (: I don't know what else to say instead of taking the decision to believe it or not.

But why not to believe in it.

[barkis]

Ain't it a shame, not one mention of poor old Pluto in the thread.  It seems the poor little mite
has been forgotten already, after it turned out to be such an exciting world too.
All those Incredible Images from the New Horizons Mission, which showed the little guy 
to have a very lovely face. It's kinda sad, don't you think?

[Dave In Vermont]

Why am I reminded of the guy in California who marketed "Pet Rocks?"

These were, quite literally, garden-variety rocks that were put in a box and sold - complete with care & feeding instructions (don't ask me what these said - I didn't fall for it!). After he had raked in a cool million $$$"s, he stopped. Used the remainders to pave his driveway with.

He rode his mighty steed - Cynicism - all the way to the bank!

Dave

[michaelmorris]

On 28/12/2016 at 02:53, N3ptune said:

Ok ok, thanks for the the opinion on the subject, it's interesting, it's special. (: I don't know what else to say instead of taking the decision to believe it or not.

But why not to believe in it.

I don't see why this is a matter of 'belief'.

As a scientist, it is not a matter of belief, it is a matter of simply following the data. It is my understanding that the composition of these meteorites is consistent with them coming from Mars and at present there is no other credible source that fits the data as well. Some possible mechanisms for these meteorites ending up on Earth have been examined and seem credible.

In the absence of other data or credible theories supported by data, it seems reasonable to have a working hypothesis that they are Martian in origin.

[Jonk]

If you watch the modern Cosmos programs with Neil DeGrasse Tyson, hey explain how over millions or billions of years, rocks are transported between planets in a system.

I can't find that particular clip online at the moment, but this clip also explains what 'happened'.