Our search for alien life has taken us in all sorts of bold new directions. From sending rovers to explore the surface of Mars to sending information across the universe using lasers and hoping for a response, scientists are trying everything. And now, NASA are developing a laser that can detect life on Earth to attempt to discover life on Mars.

The red planet is the most likely of the other planets in our solar system to host life, though the life scientists are looking for is probably not in the form of little green men. Since finding evidence of water, scientists have refocused their efforts to search for much smaller signs of life including bacteria and other microscopic organic particles.

Bio-indicator Lidar Instrument

The device is based on a similar Lidar instrument that is already in use on Earth observation satellites. The laser is used to induce fluorescence in chemicals in the atmosphere that are indicators for climate change.

When a laser reflects off its target, the particular fluorescence indicates what sort of chemical the laser has encountered. This can work for finding organic material too, and can also give an indication of the size of the particles.

A good example of how this works on a slightly larger scale is the way Igor Siwanowicz captured images of insects using a confocal laser scanning microscope. When exposed to the laser light, the different chemicals in the insects fluoresce with different colours making for a striking photo but also mapping the structure of the insects.

dragonfly thorax captured using confocal laser scanning microscope

The Bio-indicator Lidar Instrument would not provide such detailed analysis as these photographs but it could detect and ‘small levels of complex molecules from a distance of several hundred metres.’ This is an incredible thought as it would mean that the rover would not actually have to come into contact with the molecules that could cause damage or contamination.

“NASA has never used it before for planetary ground level exploration. If the agency develops it, it will be the first of a kind,” said technologist Branimir Blagojevic of the Goddard Space Flight Centre in Greenbelt, Maryland. He is leading the team developing a prototype instrument to attempt to prove that the technique is feasible.

The precision and speed of a laser is one of the great advantages of using an instrument like this. And, as soon as the laser has found a viable dust sample, scientists on Earth will be alerted immediately with the details even including how recently the organic particles came into existence.  

Diagram showing how BILI works

Image: NASA

Try and Try Again

The development of the Bio-indicator Lidar Instrument is still in its experimental phase and there are still a few features that need to be refined and perfected. Part of the problem of using any device on Mars is getting it there. The device needs to be robust enough to complete the journey successfully and then be resilient enough to withstand the climate there.

Another problem to overcome with any device is its ability to travel once on the surface of the planet. To an extent, the team have already solved part of this problem as the laser can scan areas from a distance. This means that it will be able to scan difficult to reach areas without having to risk crossing risky terrain.

As the team develop their device, there is a lot of excitement surrounding the project and what it could teach us about our nearest neighbour. The laser won’t be the first to be fired at the red planet (NASA mapped the surface using the Mars Orbiter Laser Altimeter and the Curiosity rover is still active on Mars examining the content of Martian rocks). However, the laser will be the first of its kind for the purpose of finding and studying life.

The instrument is not currently included in plans to send another rover in 2020 but we are still looking forward to seeing what Blagojevic and his team go on to do with their amazing new laser technology.