Are we all Martians? Researchers say that the evidence that supports the idea that life on Earth came from the Red Planet via a meteorite is increasing.
The idea of life coming from elsewhere isn't new. For decades, it has been hypothesized that life might have originated at some other place in the Universe and accidently landed on Earth. The new research, which is being presented at the Goldschmidt Conference, notes that an oxidized mineral form of the element molybdenum came from Mars through a meteorite.
"The evidence seems to be building that we are actually all Martians; that life started on Mars and came to Earth on a rock," said Benner, from The Westheimer Institute for Science and Technology in the USA. "It's lucky that we ended up here nevertheless, as certainly Earth has been the better of the two planets for sustaining life. If our hypothetical Martian ancestors had remained on Mars, there might not have been a story to tell."
In the absence of this form of molybdenum, life wouldn't be possible on Earth, according to Professor Steven Benner, who is presenting the research.
"It's only when molybdenum becomes highly oxidized that it is able to influence how early life formed. 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. 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," said Benner in a news release.
Recently, an analysis of Martian rock sample by NASA's Curisoity rover had shown that the planet could once have supported life. Scientists had found presence of sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon in the sample. Other research has also shown that the concentration of boron- a key element in living organisms- was higher in Martian soil than in any other extra-terrestrial object found so far.
The research conducted by Benner and colleagues addresses two paradoxes about how life emerged on Earth. The first one is the 'tar paradox', according to which organic matter will turn into tar if left with a source of energy such as heat or light instead of forming life.
"Certain elements seem able to control the propensity of organic materials to turn into tar, particularly boron and molybdenum, so we believe that minerals containing both were fundamental to life first starting," says Professor Benner. "Analysis of a Martian meteorite recently showed that there was boron on Mars; we now believe that the oxidized form of molybdenum was there too."
The second paradox is that early Earth was covered with water, which would make it impossible to accumulate enough boron to kick-start life. And, although water sustains life, it is quite harmful for primitive building block- RNA.
Mars would have been a better candidate for life as it had all the minerals and just enough water.
This isn't the first time that Benner is in the news. Back in 2010, he was among the first scientists that disputed the claims that life was arsenic-based.
David Grinspoon, an astrobiologist from the Denver Museum of Nature and Science told NBC news that Benner's theory on Life from Mars is elegant but isn't sufficient.