Researchers found more evidence supporting the theory that certain meteorites brought the buds of life to Earth long ago.
These objects contain small molecules that can be building blocks for larger molecules necessary for the beginning of life, a NASA news release reported.
Researchers analyzed carbon-rich meteorites and found evidence of amino acids, which make up proteins; Key life components such as hair and skin are made up of proteins. They also found components that make up DNA.
Carbon-rich meteorites make up only about five percent of all recovered meteorites; the" building blocks" on the objects usually only exist in tiny parts-per-million or parts-per-billion.
"Despite their small size, these interplanetary dust particles may have provided higher quantities and a steadier supply of extraterrestrial organic material to early Earth," Michael Callahan of NASA's Goddard Space Flight Center said in the news release. "Unfortunately, there have been limited studies examining their organic composition, especially with regards to biologically relevant molecules that may have been important for the origin of life, due to the miniscule size of these samples."
The researchers are working to see if these meteorites could have been the first step in the formation of life, but the process has been difficult.
"We found amino acids in a 360 microgram sample of the Murchison meteorite," Callahan said. "This sample size is 1,000 times smaller than the typical sample size used."
"Our study was for proof-of-concept," he said. "Murchison is a well-studied meteorite. We got the same results looking at a very small fragment as we did a much larger fragment from the same meteorite. These techniques will allow us to investigate other small-scale extraterrestrial materials such as micrometeorites, interplanetary dust particles, and cometary particles in future studies."
Taking such tiny samples is not an easy task.
"Extracting much less meteorite powder translates into having much lower amino acid concentration for analyses," Callahan said. "Therefore we need the most sensitive techniques available. Also, since meteorite samples can be highly complex, techniques that are highly specific for these compounds are necessary too."
The researchers used a nanoflow liquid chromatography instrument to pick out the molecules from the meteorite samples and then used nanoelectrospray ionization to give the molecules an electric charge and allow the team to measure their mass.
"I'm particularly interested in analyzing cometary particles from the Stardust mission," Callahan said. "It's one of the reasons why I came to NASA. When I first saw a photo of the aerogel used to capture particles for the Stardust mission, I was hooked."
