India’s physicist C.V. Raman has played an unexpectedly crucial role in aiding NASA’s Perseverance rover in its recent detection of potential signs of life on Mars. Scientists relied heavily on Raman spectroscopy — a technique pioneered by Raman nearly a century ago — to analyze Martian rock samples and uncover biosignatures that hint at past microbial activity.
Raman spectroscopy works by shining a laser at a sample and studying how light scatters. Occasionally, some light shifts in wavelength due to interactions with molecules in the sample — this characteristic shift is called the Raman effect. The resulting spectrum acts like a molecular fingerprint, allowing researchers to identify specific chemical compounds, minerals, and potential biological markers even in remote or harsh environments.
In recent Mars missions, NASA’s rover collected rock samples believed to contain indicators of past life — organic compounds and minerals typically formed in water-rich settings. These materials were examined using the rover’s SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals) instrument. SHERLOC uses deep ultraviolet lasers to induce Raman scattering, which is then analyzed to detect biosignatures in situ, without destroying the sample.
Raman’s work first came into the world’s attention when he discovered this effect in 1928, while exploring light scattering in liquids. His discovery earned him the Nobel Prize in Physics in 1930 and laid the scientific foundation for spectroscopy methods used today across physics, chemistry, biology, and planetary science.
Today, the value of Raman spectroscopy is being demonstrated on Mars. A rock analyzed in 2024 was found to contain aromatic organic molecules — compounds with carbon-based ring structures often central to life — along with minerals that form or persist only in watery conditions. These findings do not prove life currently exists on Mars, but they strengthen the case that Mars may once have supported microbial life.
Experts say Raman spectroscopy is especially useful in planetary exploration because it’s non-destructive, precise, and able to work with complex mixtures. Unlike some other techniques, it can detect trace amounts of organic materials and distinguish biological markers even in settings with challenging conditions.
In all, C.V. Raman’s discovery nearly 100 years ago continues to resonate through space science. The technique he uncovered now helps us peer into Martian rocks, reading ancient chemistry and biological possibility. As missions continue, tools based on Raman spectroscopy promise to deepen our understanding of Mars and the broader search for life beyond Earth.