"It's managed to stay isolated for almost half the lifetime of the Earth," [said Greg Holland, a geochemist at Lancaster University in England]. It's a time capsule. And it doesn't just hold water. "There's a lot of hydrogen in these samples."Now, do you see why we need to go to Mars?
That's significant because hydrogen is food for some microorganisms. Hydrogen-eating microbes have been found deep in the ocean and in South African mines where chemical reactions in the rock produce a steady supply of hydrogen. And that hydrogen, says Holland, "could provide the energy for life to survive in isolation for 2 billion years."
Or do you think that we ought to start worrying about alien microbes liberated from the depths of Earth?