Scientists say they have developed a new tool that could help us detect life on other worlds, a feat that’s so far proven surprisingly tricky.
A collaboration between the University of Hawai‘i at Mānoa (UHM) and NASA, the new instrument uses something called micro-Raman spectroscopy to analyze the chemical composition of a sample by firing a laser at it. This can reveal organic compounds found in living things like amino acids, and also find minerals that are formed by biochemical processes, a possible indicator of life.
The instrument is described in a paper published in the journal Applied Optics.
“Our instrument… 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,” M. Nurul Abedin from NASA’s Langley Research Center, the study’s lead author, said in a statement.
The instrument is called the standoff ultra-compact micro-Raman (SUCR) instrument and is billed as being one of the most advanced Raman spectrometers ever developed. Such an instrument could be used on future missions to places like Mars or Europa to analyze rocks and sample for signs of past or present life.
That’s actually already being done on Europe’s upcoming ExoMars rover, scheduled to launch to Mars in mid-2020. This mission will include a Raman Laser Spectrometer (RLS) to look for organic compounds and evidence of water. That system, although not too bulky, comprises a number of parts and weighs 2.3 kilograms (5 pounds).
The SUCR, however, is much smaller and allows for a higher level of accuracy. It can analyze a spot on a sample just 10 microns (0.001 centimeters) across, compared to 50 microns for the RLS on ExoMars, allowing for more precise measurements.
Life on Mars, if it ever existed, may have consisted of microorganisms just a few microns in size. So getting as small a resolution as possible is imperative when looking for any signs of past or present life.
The small size of the new instrument – 16.5 centimeters (6.5 inches) long, 11.4 centimeters (4.5 inches) wide, and 12.7 centimeters (5 inches) tall – also makes it ideal for future space missions, where weight is a key factor.
"We had to make sure the instrument was very small and light so that it could travel aboard a small, fuel-efficient spaceship that would make the nine-month journey to Mars or the six-year journey to Europa," said Abedin.
Finding signs of life on other worlds will likely rely on instruments like these, whether the mission is robotic or crewed. So making something smaller and more accurate, well, that could make all the difference.