Primitive organic molecules can be found throughout the whole solar system, but they are mostly present in carbonaceous chondrite meteorites. They can also be found amongst the interplanetary dust particles which formed in the early days of the solar system. However, the materials that have the most scientific value for researchers are the organic molecules known to us as amino acids, because amino acids are the building blocks of proteins, the precursors for life.

A team of US and UK scientists now report to have measured for the first time the amino acids found in CR meteorites that fell in the Antarctic regions of the Earth. Proteins are substances which give living cells structure and their ability to sustain chemical reactions. The production of these complex organic molecules out of amino acids is believed to have been the first step towards the appearance of life.

Most scientists believe that the amino acids on Earth alone contributed to the appearance of life on our planet, however there are some that argue that without extraterrestrial amino acids, life would have never appeared. They say that CR meteorites that formed in the early life of the solar system, containing amino acids, impacted the Earth at some point in time and released their amino acid supply on the surface.

Albeit, although these theories may be correct, nobody ever thought about measuring the concentrations of amino acids in these space rocks, to say for certain whether CR meteorites have the right amounts of such organic substances to prove at least part of their theory.

While measuring the contents of three meteorites found in the Arctic continent, researchers revealed that the amino acid concentration could actually exceed over ten times the quantity found in other meteorites. The three meteorites in question are EET92042, GRA95229 and GRO95577, and were collected during expeditions between 1992 to 1995.

Most meteorites that fall on the surface of the Earth contain amino acid concentrations of less than 15 parts per million, however two of these particular meteorites have concentrations ranging between 249 parts per million to 180 parts per million.

"The Antarctic CR2s EET92042 and GRA95229 have the highest amino acid abundance ave detected. This suggests that their soluble organic inventories are more primitive than any other chondrites and, therefore, close to the original material accreted by chondrites. The analysis of the amino acids present in Antarctic CR meteorites will help to reveal the processes that formed the prebiotic organ material in the early solar system that may ultimately have been delivered to the Earth and other planets," says the research team in the study.

GRO95577, on the other hand, presented an extremely low concentration of amino acids.