The Miller-Urey experiment originally created a stir because the chemists managed to create organic materials from inorganic ones. This turned the study of the origins of life, abiogenesis, on its head. It suggested that life on Earth could be the result of lightning strikes in an atmosphere filled with ammonia, hydrogen, and methane. But the amino acids never formed more complex proteins, and the products of the experiment, including the vials of artificially induced proto-life, were placed in storage.

After Miller’s death last year, a marine chemist Jeffrey Bada discovered the materials, as well as Miller’s notes on the experiment. These notes included the suggestion to add steam to the electrical sparks in order to replicate the conditions of early Earth. By updating Miller’s techniques, Bada has been able to produce 22 amino acids from inorganic matter, 17 more than the original experiment.

Said Bada:

It just opens our eyes. It’s still revealing new things. What else is there that we haven’t found out from this experiment?

This still doesn’t solve the question of how abiogenesis occurred on Earth, nor does it rule out the possibility of extraterrestrial contributions to our DNA. But it does prove that sometimes it pays to be a packrat.

Image from Scripps Institute of Oceanography.

From Old Vials, New Hints on Origin of Life [NY Times]

Panspermia theories often argue that Martian mircobes hitched a ride on an Earth-bound meteor, then thrived and evolved into the life we see here on Earth. But the new findings from researchers at Imperial College London suggest the building blocks of life rather than life itself arrived from outer space. They figure that since the Murchison meteor fell to Earth bringing the molecules uracial and xanthine — precursors to DNA — there must have been a lot of this stuff pelting the planet billions of years ago.

Early life may have needed the space-born material to get started, or it could've incorporated the meteorite bits because they conferred some kind of evolutionary advantage:

Lead author Dr Zita Martins, of the Department of Earth Science and Engineering at Imperial College London, says that the research may provide another piece of evidence explaining the evolution of early life. She says:

“We believe early life may have adopted nucleobases from meteoritic fragments for use in genetic coding which enabled them to pass on their successful features to subsequent generations.”

Between 3.8 to 4.5 billion years ago large numbers of rocks similar to the Murchison meteorite rained down on Earth at the time when primitive life was forming. The heavy bombardment would have dropped large amounts of meteorite material to the surface on planets like Earth and Mars.

Either way, it looks like we're made of space stuff.

Source: Imperial College London