Researchers have developed a new instrument, which improves on an analytical technique known as micro Raman spectroscopy. This technique uses the interaction between laser light and a sample to provide chemical composition information on a microscopic scale. It can detect organic compounds such as the amino acids found in living things and identify minerals formed by biochemical processes on Earth that might indicate life on other planets. This study got published in The Optical Society Journal Applied Optics.

NASA has developed an innovative new spectroscopy instrument to aid the search for extraterrestrial life. The new instrument is designed to detect compounds and minerals associated with biological activity more quickly and with greater sensitivity than previous instruments. Although no evidence of life outside of Earth has yet been found, looking for evidence of present or past life on other planets continues to be an important part of the NASA Planetary Exploration Program.

Researchers described a new system, which they call the standoff ultra-compact micro Raman (SUCR) instrument. It is the first to perform micro-Raman analysis of samples 10 centimeters away from the instrument with 17.3-micron resolution. The new spectrometer is significantly faster than other micro Raman instruments and extremely compact. These features are important for space applications and could also make the instrument useful for real-time biomedical and food analyses.

Designing for space

Size and weight were important to consider when designing the SUCR instrument for space exploration. Abedin said, "The instrument must also work with other instruments aboard a rover or lander and be unaffected by the harsh radiation conditions found on other planets." The new instrument offers several important improvements to previous micro Raman spectroscopy instruments, which require samples to be collected prior to analysis and measurements to take place in the dark.

To create the SUCR instrument, the researchers modified the collection optics of the previously developed system to acquire spectra of samples closer to the instrument. They also further reduced system's footprint by using a miniaturized spectrometer just 16.5 centimeters long, 11.4 centimeters wide and 12.7 centimeters tall. Passing light from a compact pulsed laser through a cylindrical lens with a focal length of 100 millimeters allowed the researchers to achieve 17.3-micron resolution for analysis of samples 10 centimeters away.

They also demonstrated 10-micron resolution for samples 6 centimeters away using a cylindrical lens with a 60-millimeter focal length. For future aspects, researchers plan to test their SUCR instrument in environments that mimic those found on Mars and other planets. They will then begin the validation process to show that the device would operate accurately under conditions found in space.