Earth life 'may have come from Mars'
New research, presented at a major scientific conference, supports the view that the conditions on Mars were more favourable for kick-starting life’s building blocks than Earth, suggesting that life started on Mars and came to Earth on a meteorite.
Details of the theory were outlined by Professor Steven Benner at the Goldschmidt Meeting in Florence, Italy. The evidence is based on how the first molecules necessary for life were assembled. Scientists have long wondered how atoms first came together to make up the three crucial molecular components of living organisms: RNA, DNA and proteins.
The molecules that combined to form genetic material are far more complex than the primordial soup of carbon-based chemicals thought to have existed on the Earth more than three billion years ago, and RNA is thought to have been the first of them to appear.
The minerals most effective at forming RNA, boron and molybdenum, would not have existed in a sufficient form or quantity in the early Earth, but would have been more abundant on Mars, according to Professor Benner. This could suggest that life started on the Red Planet before being transported to Earth on meteorites.
"This form of molybdenum couldn’t have been available on Earth at the time life first began, because three billion years ago, the surface of the Earth had very little oxygen, but Mars did,” said Professor Benner. "It’s yet another piece of evidence which makes it more likely life came to Earth on a Martian meteorite, rather than starting on this planet."
Meteorites from Mars have been arriving on Earth throughout our planet's history so Benner’s theory is certainly not implausible.
"The evidence seems to be building that we are actually all Martians; that life started on Mars and came to Earth on a rock," he commented.