Researchers built the laser to detect signs of life and for identifying materials taken from other planets.
But they also had to shrink it down into a package that could be small and light enough to be taken to those other planets, on board spacecraft with limited resources.
To do that, they shrunk down a system that was originally built for commercial use, and which can be found throughout laboratories around the world. Over eight years, scientists built a version that could be taken into space.
The system that resulted weighs just 17 pounds and is a combination of two tools that can be used for studying other planets. One is an ultraviolet laser that can take small amounts of material from a sample, and another is an analyser known as an “Orbitrap” that can study the chemistry of that material.
“The Orbitrap was originally built for commercial use,” explained Ricardo Arevalo, lead author of the paper and an associate professor of geology at the University of Maryland, in a statement.
“You can find them in the labs of pharmaceutical, medical and proteomic industries. The one in my own lab is just under 400 pounds, so they’re quite large, and it took us eight years to make a prototype that could be used efficiently in space—significantly smaller and less resource-intensive, but still capable of cutting-edge science.”
The shrunken down version should be small enough to be stored on a space mission, its creators say, and uses little energy so that it would not cause unhelpful demand on batteries of power resources. It is also a less intrusive way of analysing material, so that samples should be less likely to be contaminated.
“The good thing about a laser source is that anything that can be ionized can be analyzed. If we shoot our laser beam at an ice sample, we should be able to characterize the composition of the ice and see biosignatures in it,” said Professor Arevalo.
“This tool has such a high mass resolution and accuracy that any molecular or chemical structures in a sample become much more identifiable.”
Scientists also hope that the use of the new system will allow them to find larger, more complex compounds that can be a more definitive sign of alien life. Existing systems have been able to detect smaller compounds, such as amino acids – but those are more ambiguous as evidence of life on other worlds.
“Amino acids can be produced abiotically, meaning that they’re not necessarily proof of life. Meteorites, many of which are chock full of amino acids, can crash onto a planet’s surface and deliver abiotic organics to the surface,” said Professor Arevalo.
“We know now that larger and more complex molecules, like proteins, are more likely to have been created by or associated with living systems. The laser lets us study larger and more complex organics that can reflect higher fidelity biosignatures than smaller, simpler compounds.”
A paper describing the work, ‘Laser Desorption Mass Spectrometry with an Orbitrap Analyzer for in situ Astrobiology,” is published in Nature Astronomy.