Microbial Morphology and Motility as Biosignatures for Outer Planet Missions

Area of Science:

• Astrobiology
• Microbiology
• Planetary Science

Background:

• Meaningful motion is a definitive biosignature.
• Microbial life is the most probable form of extraterrestrial life in the Solar System.
• Understanding microbial motility is crucial for detecting biosignatures.

Purpose of the Study:

• To review recent findings on microbial motility in Earth environments.
• To assess the detectability of microbial motion on the micrometer scale.
• To contextualize these findings for astrobiological applications, particularly in outer Solar System environments.

Main Methods:

• Review of recent research on microbial motility physics and biology.
• Analysis of conditions and speeds of bacterial and archaeal swimming.
• Evaluation of imaging technologies for submicrometer organism motility detection.
• Discussion of instrument-sample collection interface strategies.

Main Results:

• Microbial motility can be effectively studied and characterized.
• Specific physical and biological factors govern microbial swimming.
• Existing and developing technologies show promise for detecting micro-scale motion.
• Outer Solar System environments, like icy moons, present unique challenges and opportunities.

Conclusions:

• Microbial motion is a viable and detectable biosignature.
• Further research into microbial motility is essential for astrobiology.
• Technological advancements are key to in situ detection of life.
• Focusing on motility can guide the search for life beyond Earth.