A new tiny laser could be a game changer in the hunt for alien life

A team led by the University of Maryland created a miniature analyzer that could fundamentally alter how distant moons and planets are investigated for signs of life.
Christopher McFadden
ldms-orbitrap.jpg
An image of the new LDMS Orbitrap device.

Ricardo Arevalo et al 2023 

As space missions explore the outer solar system, they need analytical tools that are smaller, use less energy, and are more accurate. This is especially true since the search for extraterrestrial life, and habitable planets and moons are still ongoing.

This is where a new piece of equipment unveiled in an article titled "Laser Desorption Mass Spectrometry with an Orbitrap Analyzer for In situ Astrobiology," published in the journal Nature Astronomy, could prove pivotal.

Under the direction of the University of Maryland, a group of researchers made a new instrument for NASA space missions as part of the study. Their small, laser-powered analyzer can still look at samples of a planet's material and possible signs of life on the spot.

At the same time, it is substantially smaller and more resource-efficient than its predecessors.

The instrument, which weighs only about 17 pounds (7.7 kg), is a scaled-down version of two important tools for finding signs of life and figuring out what materials are made of: a pulsed ultraviolet laser that removes tiny amounts of material from a planetary sample and an Orbitrap analyzer that gives high-resolution information about the chemistry of the materials being looked at.

“The Orbitrap was originally built for commercial use,” explained Ricardo Arevalo, lead author of the paper and an associate professor of geology at UMD.

“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,” he added.

The new device uses LDMS

Researchers made a new device smaller than the original Orbitrap and combined it with laser desorption mass spectrometry (LDMS). This technique has never been used on a planet outside of Earth.

Arevalo says the new device has the same benefits as its bigger predecessors. Still, it is smaller, so it can be used for space exploration and studying planetary materials right on the planet.

Due to its small size and low power needs, the Orbitrap LDMS instrument is easy to pack away and keep running on space missions. The instrument's studies of a planet's surface or material are much less invasive than many current methods that identify unknown substances. This makes it much less likely that a sample will be contaminated or damaged.

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“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,” Arevalo said.

“This tool has such a high mass resolution and accuracy that any molecular or chemical structures in a sample become much more identifiable,” he added.

The new device could be a game changer for detecting alien life

Researchers now have access to larger, more complex molecules that are more likely to be linked to biology because of the laser component of the small LDMS Orbitrap. For example, amino acids are a less clear sign of life than larger organic molecules.

“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,” Arevalo said.

“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,” he added.

The tiny LDMS Orbitrap will give Arevalo and his colleagues much-needed information and flexibility for future trips to the outer solar system, such as missions to look for life (like the Enceladus Orbilander) and to explore the surface of the Moon (like the NASA Artemis Program).

Within the next five years, they intend to launch their equipment into space and set it up on an attractive planetary target.

“I view this prototype as a pathfinder for other future LDMS and Orbitrap-based instruments,” Arevalo said. “Our mini Orbitrap LDMS instrument has the potential to significantly enhance the way we currently study the geochemistry or astrobiology of a planetary surface,” he added.

You can read the study for yourself in the journal Nature Astronomy.

Study abstract:

Laser desorption mass spectrometry (LDMS) enables in situ characterization of the organic content and chemical composition of planetary materials without requiring extensive sample processing. Coupled with an Orbitrap analyser capable of ultrahigh mass-resolving powers and accuracies, LDMS techniques facilitate the orthogonal detection of a wide range of biomarkers and classification of host mineralogy. Here an Orbitrap LDMS instrument that has been miniaturized for planetary exploration is shown to meet the performance standards of commercial systems and exceed key figures of merit of heritage spaceflight technologies, including those baselined for near-term mission opportunities. Biogenic compounds at area densities relevant to prospective missions to ocean worlds are identified unambiguously by redundant measurements of molecular ions (with and without salt adducts) and diagnostic fragments. The derivation of collision cross-sections serves to corroborate assignments and inform on molecular structure. Access to trace elements down to parts per million by weight levels provide insights into sample mineralogy and provenance. These analytical capabilities position the miniaturized LDMS described here for a wide range of high-priority mission concepts, such as those focused on life detection objectives (for example, Enceladus Orbilander) and progressive exploration of the lunar surface (for example, via the NASA Artemis Program).

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