NASA has developed a new tool, designed to detect compounds and minerals associated with biological activity, to help the search for alien life. 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 Programme. Researchers at NASA Langley Research Center and the University of Hawaii in the US developed the 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. “Our instrument is one of the most advanced Raman spectrometers ever developed,” said M Nurul Abedin of NASA Langley Research Center, who led the research team. “It overcomes some of the key limitations of traditional micro Raman instruments and is designed to serve as an ideal instrument for future missions that use rovers or landers to explore the surface of Mars or Jupiter’s icy Europa Moon,” said Abedin.
The new system – called the standoff ultra-compact micro Raman (SUCR) instrument – is the first to perform micro-Raman analysis of samples 10 centimetres 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, according to the study published in the journal Applied Optics.
“Micro Raman spectroscopy is being explored for detecting skin cancer without a biopsy and can be used to for food analysis applications such as measuring caffeine in drinks,” said Abedin. “Our system could be used for these applications and others to provide fast chemical analysis that doesn’t require sending samples off to a laboratory,” he said. 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.
Traditional micro Raman instruments are also prone to interference from natural mineral fluorescence. In laboratory tests, the researchers used their SUCR instrument to successfully measure Raman spectra from samples 10 centimetres away with an analysis area of 17.3 microns by 5 millimetres. In room light on conditions, they used SUCR to analyse minerals and organic compounds that might be associated with life on other planets, including included sulphur, naphthalene, mixed samples, marble, water, calcite minerals and amino acids.