Researchers from our Institute have developed a laser technology device that can detect life in extreme environments. A first test in the high deserts of Chile proved to be a success.
Christian Burlet and Yves Vanbrabant (Royal Belgian Institute of Natural Sciences) created a ‘laser ablation spectrometer’ that can detect minerals and bacterial traces in an environment similar to the harsh conditions on Mars. The device was tested during a joint SETI - Nasa Astrobiological Institute (NAI) mission in Chile. It is possibly the smallest research-grade model in the world.
The spectrometer received the name Alpheid, from a family of pistol shrimp. These animals can shoot ‘water bullets’ by snapping their claw with extreme power. ‘The pistol shrimp snaps his claw with such speed that it generates a high velocity jet of water, with temperature reaching thousands of degrees and sometimes producing a flash of light,' Christian Burlet explains. 'The spectrometer produces a similar phenomenon, but with an infrared laser that produces a tiny spark of plasma light.’
LIBS, laser-induced breakdown spectroscopy, is a technique that consists of shooting a powerful laser pulse (very short pulse) on a sample and measuring the light produced while ablating a tiny fraction of the material. The spectrometer can identify all the elements of the sample, because every element, and in some case molecules, emits light with a specific wavelength.
The idea to use LIBS for planetary explorations is not new: the NASA Mars Curiosity Rover already features this kind of spectrometer, the MSL Chemcam, but it is very heavy. ‘With Alpheid, we put all this in a package as compact as possible – it weighs less than 2 kg', says Burlet.
The compactness of the device opens up new possibilities. ‘Our prototype will never travel to Mars in its current form, but it can serve as a base design for future instruments. Some of the proposed concepts include ideas of compact instruments mounted on very small rovers or even aerial platforms!’
Alpheid did an excellent job in the desert of Chile (Salar Grande, Geiser del Tatio, Lejía Lake), an environment so extreme for life it can be compared to the Martian surface. ‘The instrument was able to record the mineralogical compositions of the soils and rock and detect organic matter just under the surface of samples thanks to its ablative process.’
For now, Christian Burlet and his colleagues will further develop Alpheid for research on Earth, to analyse rock properties and soil contaminations. ‘But we can always dream. The Alpheid instrument has been included in four NASA research proposals submitted by the SETI this year. So wait and see, if one of them gets funded we will have the possibility to improve it and maybe send it in space!’