These are just some hypothesis, but some proof real exist
• The proof is Martian meteorite "Allen - hills 84001". The Martian meteorite was found at Antarctic on December 27, 1984. Scientists in NASA analyzed the crystal structure of meteorite(陨石的晶体结构) and found that about 25% of the crystal was formed by bacteria(细菌). This is the strongest evidence yet for the existence of life on the Mars.
water bear
(水熊虫)
I survived
• Let us to know an invertebrate(无脊椎动 物) named water bear(水熊虫), then you will know how strong life is. The European Space Agency(欧洲太空总署) took some water bears to the space using satellite, exposed them to the space environment, let them without air and took 1000 times the radiation of other creatures on the ground. The water bears suspended their all life activates in the extreme space environment. But when the satellite back on earth, the researchers examined the water bear and the result showed that most of them were survived. I think if we throw some water bears to the Mars, millions years later we may harvest Martians.