Biosignature stability in space enables their use for life detection on Mars

Area of Science:

• Astrobiology
• Planetary Science
• Spectroscopy

Background:

• Mars rover missions utilize Raman spectroscopy to detect biomolecules, potential biosignatures of life.
• The stability of these biomolecules in the Martian environment is largely unknown, impacting data interpretation.

Purpose of the Study:

• To quantify the stability of Raman-detectable biomolecules under simulated Martian conditions.
• To assess the impact of ultraviolet radiation (UVR) on biomolecule detectability.

Main Methods:

• Seven different biomolecules were exposed for 469 days in a simulated Martian environment outside the International Space Station.
• Raman spectroscopy was used to analyze changes in biomolecule signals before and after exposure, with and without UVR shielding.

Main Results:

• Exposure to ultraviolet radiation (UVR) significantly altered the Raman spectra of the tested biomolecules.
• Biomolecules shielded from UVR exhibited only minor spectral changes, indicating greater stability.

Conclusions:

• Biomolecule stability is significantly affected by UVR on Mars, suggesting subsurface environments are more promising for detecting biosignatures.
• This study validates the use of Raman spectroscopy for detecting biomolecules in Martian regolith analogs after space exposure.