Meteorites that bombarded Earth four billion years ago could have kick-started life rather than wiping it out, a study shows.
Scientists have taken fragments from a meteorite in the Antarctic and by bombarding it with heat and pressure have recreated conditions at the beginning of life as we know it, they believe.
They have found that the rock emitted ammonia under primordial conditions, an essential compound in the production of amino acids, the so-called building blocks of life.
The researchers analysed the nitrogen atoms within the ammonia and determined that the atomic isotope did not match those currently found on Earth, discarding the possibility that the ammonia resulted from contamination during the experiment.
The earliest physical evidence of life on Earth in the shape of fossils dates back to 3.8 billion years
Nobody really knows how life started on earth but it is thought have been a freak occurrence sparked by the extreme pressure and heat mixing with chemicals from outer space.
These findings, made by Arizona State University, suggest that these chemicals came from meteorites, which seeded the Earth with the necessary chemicals.
The work was published in the journal Proceedings of the National Academy of Sciences.