Life might have started on Mars and come to Earth on a meteorite, experts say, after discovery of water on Red Planet

The discovery of water on Mars might be huge for the discovery of alien life. But we might get there to find that the aliens on the planet are our relatives.

The very beginnings of Earth may have begun with elements delivered here from Mars, experts have speculated. And when we get to Mars we might find that we’ve been there — in a very different form — before.

Scientists have long been unsure about where the very earliest building blocks of life came from. But one of the main theories about where that began is that it came here on an asteroid — and they might have been transported here from Mars.

The theories were revived by author Andrew Smith, who has written about the search for life on Mars, in the wake of the discovery of water on the planet. That finding increase the chances of there being life on the Red Planet.

“One of the possibilities that scientists discuss is that we might all be Martians,” he said on the Today programme. “Life may have originated there and come here on meteorites — we have Martian meteorites on Earth.”

He also pointed out that we long presumed there would never be anything living on Mars, since the environment is so harsh. But we have in recent decades found new beings called “extremophiles” — living things that inhabit places that would have previously been presumed never to be able to support life.

The theory arises from the fact that billions of years ago, Mars would have been a much more hospitable place for human life than Earth was. Two elements that allow life to begin were likely unavailable on Earth but would probably have been around on Mars, some scientists have claimed.

One of those elements required is boron, which is required to form RNA, an early expression of genes and as far as we know something that is essential to life. Boron was scarce on the early Earth — and has been delivered by at least one meteorite from Mars.

Any life that is left on Mars is likely to be microbial and hidden — and even that will be very difficult to find because there are huge problems with sending man-made equipment to explore the areas where it might be.