Part of the show Space Science & Extraterrestrial Life
Is it possible that life on Mars managed to hitch a ride on a meteorite and started life on Earth?
We think that conditions on the early Earth were very bad for life as there was no atmosphere. Mars might have been a better place to live at that time, and so life could have started there but we just don't know. To find out if life really did get going on Mars, we need to go there and have a look.