Explanation:

The Bio-Indicator Lidar Instrument:
• The Bio-Indicator Lidar Instrument, or 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.
• 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.
• It is a sensing technique that the US military currently uses to remotely monitor the air to detect potentially life-threatening chemicals, toxins, and pathogens.
• The beauty of BILI is its ability to detect in real-time small levels of complex organic materials from a distance of several hundred meters
This can be used to detect signatures of life on Mars.