[gondramB]

So how does the rock leave Mars? Does it leap off the planet?

[GAB-1955]

"So how does the rock leave Mars? Does it leap off the planet?"

Meteors hit Mars. The impact scatters rock from the surface of Mars up and out. Some reach Martian escape velocity and go into solar orbit. Of these, some become meteorites and reach the surface of Earth. The composition of Mars and the Earth are dissimilar enough that we know that this has happened. One meterorite in 1984 reached Antarctica; it had the possibility that microbial life existed on Mars.

Several scientists believe that life in the universe is common -- if it's microbial, similar to domains Archaea and Bacteria here. What is rare would be complex life such as lichen and rotifers, let alone humans.

[SengirV]

[ARCADIA]

So how does the rock leave Mars? Does it leap off the planet?

It can be blasted off the planet by a collision. There is even a school of thought which argues that our own moon was made of materials knocked off the earth.

[darth]

The rocks we have recovered show the isotopic "signature" of Mars origin. Every planet has isotopes in different proportions that indicate the origin of such rocks when they fall on Earth. We determined the Mars signature from the Viking probe and other subsequent missions. The rocks were blasted off Mars by massive impacts by asteroids and comets. Calculations of the speed of ejecta from the impacts show that the rocks could attain escape velocity from Mars and go into orbit around the Sun. The Allen Hills meteorites are almost certainly from Mars. In the center of the one meteorites the NASA team found fossils of nanobacteria. Since Mars was warm and had oceans while the Earth was still above the boiling point of water, the theory is that Mars could easily have had life before Earth. When the Earth cooled down, Martian rocks could have seeded the early Earth with bacteria spores. Sorry about the impact on theology. We just want the truth regardless of whether it offends anyone. When we find life on Mars (and I am willing to bet money on this) the bacteria DNA will tell us whether it has a common ancestor with us. Humans share DNA with more primitive lifeforms including bacteria. Flame away.

[jps098]

And escaped it's gravity and traveled across to the earth, did not burn up in the atmosphere, was found in the middle of nowhere, was split open at just the right spot, and a few people think it once had a single bacteria just before Congress was to cut funding for a program.

And Christians have "blind faith"?

[jrg]

So how does the rock leave Mars? Does it leap off the planet?

And where do you think "Pet Rocks" originated?

[OB1kNOb]

Everyone knows that men are from Mars.
Women are from Venus.
I guess dimos came from Uranus.

[MineralMan]

"So how does the rock leave Mars? Does it leap off the planet?"

No. As you may know, Mars' gravity is somewhat lower than ours. The rocks get here when Martian teenagers, lacking anything better to do, construct crude catapults, then load stones into them. They fire these stones into the air, and some of them reach a high enough velocity to escape Mars' gravitational field. A few of those manage to reach Earth.

It's such a common phenomenon on Mars that government studies have been done, leading to the conclusion that the youth of Mars no longer respect their elders have stopped reading the scriptures and are going to Hell in a handbasket.

I hope that helps.

[RightWhale]

Does it leap off the planet?

Yes, sort of. Blasted off by meteorite impact. It's relatively easy and some of the debris can end up on earth.