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Updated: Aug 1, 2026
08:51
Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers
Published on: August 18, 2017
A search for chiral signatures on Mars
William B Sparks1, James H Hough, Louis E Bergeron
1Space Telescope Science Institute, Baltimore, MD, USA. sparks@stsci.edu
Astrobiology
|December 29, 2005
Summary
Scientists searched for signs of life on Mars by looking for circular polarization of light. No evidence of anomalous optical activity was found, suggesting no widespread chiral molecules on the Martian surface.
Area of Science:
- Astrobiology
- Planetary Science
- Optics
Background:
- Chiral molecules in living organisms can circularly polarize light.
- This phenomenon could be a biosignature, indicating extraterrestrial life.
- Previous studies suggested potential for high levels of optical activity from life.
Purpose of the Study:
- To search for evidence of anomalous optical activity on the Martian surface.
- To investigate the presence of chiral molecules as potential biosignatures on Mars.
- To utilize high-quality imaging circular polarimetry during a favorable Martian opposition.
Main Methods:
- Acquired high-quality imaging circular polarimetry data of the Martian surface.
- Used two narrow-band filters, covering 43% of the surface area.
- Achieved polarization noise levels below 0.1% and spatial resolution of 210 km.
Main Results:
- No specific regions exhibiting circular polarization were detected on the Martian surface.
- A small, non-zero circular polarization (0.02%) was observed when data were averaged globally.
- This global signal is at the instrumental limit and may be an artifact of the opposition effect.
Conclusions:
- The study found no definitive evidence for widespread anomalous optical activity on Mars.
- The null result does not exclude the possibility of optical activity at other wavelengths, locations, or resolutions.
- Further observations are needed to fully explore Mars's potential for hosting chiral molecules.
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