Origin of Life on Earth: Meteorites Provided Ingredients for Primordial Soup

The origin of life on Earth may finally be solved--at least partly. Researchers have discovered how objects from space may have helped provide the ingredients for the primordial soup of our ancient seas.

Researchers generally accept that some important components for life actually came from meteorites bombarding the Earth early in its history. Yet until now, scientists have been unable to explain exactly how inanimate rock was able to transform into the building blocks of life. In order to find out exactly how these cosmic missiles could have played a role early in our history, researchers examined the conditions that meteorites may have encountered on a young Earth.

All life on Earth is powered by a process called chemiosmosis, where adenosine triphosphate (ATP) is broken down and reformed during respiration to release energy. This energy is used to drive actions that are crucial to an organism's metabolism. Yet the complex enzymes needed to create and break down ATP are unlikely to have existed on Earth when life first developed. Therefore, it's possible that a far simpler chemical with properties similar to ATP was around during that time.

In order to examine early meteorite impacts, researchers simulated the conditions that these missiles probably encountered--a volcanically-active, hot Earth. They placed samples of a meteorite which fell in Siberia in 1947 in acid taken from the Hveradalur geothermal area in Iceland. The rock was then left to react with the acidic fluid in test tubes that were incubated by the surrounding hot spring for four days. This was followed by a further 30 days at room temperature.

In the end, the scientists discovered the compound pyrophosphate in the solution. This compound is a molecular "cousin" of pyrophosphate, which is the part of ATP responsible for energy transfer. It's possible that this new compound could have acted as an earlier form of ATP.

"The mystery of how living organisms sprung out of lifeless rock has long puzzled scientists, but we think that the unusual phosphorus chemicals we found could be a precursor to the batteries that now power all life on Earth," said Terry Kee, who led the research team, in a press release. "But the fact that it developed simply, in conditions similar to the early Earth, suggests this could be the missing link between geology and biology."

While this research may demonstrate a theory about how life may have first arisen on Earth, there's no guarantee that it's the correct one. More studies will need to be conducted before any firm conclusions are made.

The findings are published in the journal Geochimica et Cosmochimica Acta.