14 DAY TRIAL // A group of scientists with the Astrobiology Analytical Laboratory at the NASA Goddard Space Flight Center in Greenbelt, Maryland, is currently using a series of advanced technologies to identify the components of life in extremely small meteorite samples. Their approach requires significantly less material than other methods.
Team leader Michael Callahan says that the most recent studies conducted on materials brought to Earth by comet and meteor impacts appear to support a hypothesis claiming that life is possible on Earth – at least in part – due to these violent impacts.
The actual origins of life remain mysterious and open for debate at this point, but what the hypothesis argues is that the development of life here on Earth would have been impossible billions of years ago without material that was created in space, and then brought here on various impactors.
Several meteorite studies have determined that these space rocks feature molecules that are commonly used for creating the building blocks of life, chemicals that are critical for all living organisms. For example, carbonaceous chondrites (carbon-rich meteorites) were found to contain amino-acids.
These small molecules are absolutely critical to the development of proteins, the most important structures for life. Geologists have also identified the building blocks of DNA in material brought here from outer space. But researchers at GSFC wanted to know if the other important source of cosmic material – cometary and asteroid dust – contains these important molecules as well.
“Despite their small size, these interplanetary dust particles may have provided higher quantities and a steadier supply of extraterrestrial organic material to early Earth,” Callahan explains.
“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 minuscule size of these samples,” he adds. With the new technology available at the AAL, such studies are now possible.
“We found amino acids in a 360 microgram sample of the Murchison meteorite. This sample size is 1,000 times smaller than the typical sample size used,” Callahan says. Implementing this research method worldwide could lead to a deeper understanding of the role meteors, comets and interplanetary dust played in the development of life on Earth.