Uncovering This Intelligent Strategy Might Aid in Identifying Extraterrestrial Life on Mars
Rovers sent to Mars haven't found life, leading many to believe it's not there. But we can't be certain, so the hunt continues, using innovative methods like this one proposed by a team of scientists.
As explained in a recent study published in Frontiers in Astronomy and Space Sciences, astrobiologists from Germany and Portugal discovered that three types of microbes are attracted to an amino acid called L-serine. This phenomenon, known as chemotaxis, could be a game-changer in our quest for microscopic extraterrestrial life, including on Mars.
"Given that early Earth and Mars were hit by carbonaceous asteroids, L-serine likely exists on Mars," the researchers wrote in the study. Previous research has already shown that L-serine induces chemotaxis in some life forms. "If life developed on Mars with a similar biochemistry to known life on Earth, it seems plausible that L-serine could also attract hypothetical Martian microbes," they added.
To test their theory, the researchers used "hypothetical Martian microbes" known for withstanding harsh conditions. These included bacteria like Bacillus subtilis and Pseudoalteromonas haloplanktis, as well as the archaea Haloferax volcanii.
"Bacteria and archaea are two of the oldest life forms on Earth, but they move differently and developed their motility systems independently," Max Riekeles, an aerospace engineer at the Technical University of Berlin and co-author on the study, explained. "By testing both groups, we can make life detection methods more reliable for space missions."
Their approach, relying on the microbes' chemotactic behavior towards L-serine, showed promise. The researchers used a simple setup, separating microbes in one chamber from L-serine in another by a thin membrane. If the microbes were alive and motile, they would swim towards the L-serine. And that's exactly what happened, suggesting that future astronauts could use this method to identify potential microbial life in extraterrestrial samples.
The method's appeal lies in its simplicity and affordability. It doesn't require advanced equipment or powerful computers to analyze results. Despite the need for refinements for space missions, the study underscores the potential of a cheaper and simpler approach to search for extraterrestrial life.
Enrichment Insights:
- Chemotactic Behavior: The study confirmed chemotactic behavior in all three microorganisms tested. This response to L-serine could serve as a strong signal of life in future space missions.
- Universal Biosignature: L-serine is a universal biosignature, shown to induce chemotaxis in various life forms. If Martian life shares similar biochemistry with Earth's, L-serine could potentially serve as an attractant for Martian microbes.
- Resilient Microorganisms: The researchers chose microbes known for surviving in harsh environments, such as Bacillus subtilis slowly cooking in temperatures up to 100°C or the archaea Haloferax volcanii thriving in the Dead Sea's high salinity.
- Potential for Water Ice Moons: The chemotaxis-based method could be particularly useful for detecting life on icy moons, like Europa, Enceladus, and Titan, where microbial ecosystems may exist beneath thick ice layers.
- Simplified Technique: The method's simplicity and affordability make it a cost-effective and easy-to-implement alternative to existing life detection techniques. However, modifications are necessary for space missions, including compact and durable equipment and automation for independent functioning.
The discovery of L-serine's attracting power towards three types of microbes on Earth could potentially be extended to Mars, given the presence of this amino acid on early Mars. This hypothesis, if proven, could revolutionize the use of technology in the search for microscopic life in space, including on Mars.
The future of space exploration and the field of astrobiology could significantly benefit from the development of simpler and more affordable methods for identifying extraterrestrial life, such as this chemotaxis-based technique.
