NASA scientists have developed a new instrument that may “sniff” for signs of life on Mars, inspired by a sensing technique used to monitor the air for life-threatening chemicals and bio-hazards.
The Bio-Indicator Lidar Instrument (BILI) is a fluorescence-based lidar, a type of remote-sensing instrument similar to radar in principle and operation.
Instead of using radio waves, however, lidar instruments use light to detect and ultimately analyse the composition of particles in the atmosphere.
Branimir Blagojevic, a NASA technologist at the Goddard Space Flight Centre in the US created a prototype, showing that the same remote-sensing technology used to identify bio-hazards in public places also could be effective at detecting organic bio-signatures on Mars.
Although NASA has used fluorescence instruments to detect chemicals in Earth’s atmosphere as part of its climate-studies research, the agency so far hasn’t employed the technique in planetary studies.
“NASA has never used it before for planetary ground level exploration. If the agency develops it, it will be the first of a kind,” Blagojevic said.
As a planetary-exploration tool, researchers envision BILI as primarily “a rover’s sense of smell.”
Positioned on a rover’s mast, BILI would first scan the terrain looking for dust plumes. Once detected, the instrument, then would command its two ultraviolet lasers to pulse light at the dust.
The illumination would cause the particles inside these dust clouds to resonate or fluoresce.
By analysing the fluorescence, scientists could determine if the dust contained organic particles created relatively recently or in the past. The data also would show the particles’ size.
“If the bio-signatures are there, it could be detected in the dust,” Blagojevic saidl.
BILI has the ability to detect in real-time small levels of complex organic materials from a distance of several hundred meters.
Therefore, it could autonomously search for bio-signatures in plumes above recurring slopes – areas not easily traversed by a rover carrying a variety of in-situ instruments for detailed chemical and biological analysis.
Furthermore, because it could do a ground-level aerosol analysis from afar, BILI reduces the risk of sample contamination that could skew the results.
“This makes our instrument an excellent complementary organic-detection instrument, which we could use in tandem with more sensitive, point sensor-type mass spectrometers that can only measure a small amount of material at once,” Blagojevic said.
“BILI’s measurements do not require consumables other than electrical power and can be conducted quickly over a broad area. This is a survey instrument, with a nose for certain molecules,” he said.