The purpose of this project is to develop an optical method for detecting the presence of life, specifically microorganisms, in the atmosphere of an exoplanet. We are developing algorithms that distinguish between aerosols of biological origin (microorganisms) from aerosols of non-biological origin (dust, hydrosols, etc.) using analysis of their respective and combined extinction spectra. The method uses large databases of computer-modeled spectra to analyze optical measurements and identify biological aerosols. Whereas most exoplanet researchers focus on detecting molecular spectral signatures, we are focusing on detecting the microorganisms directly rather than their molecular by-products. This method holds significant potential for detecting microorganisms from light scattered from an exoplanet’s atmosphere.
In order to simulate exoplanet atmospheres using information available today, Jupiter’s atmosphere was used as a model. This was accomplished by creating a MATLAB program that simulates the scattering of light using complex mathematical models. The optical information for clouds of different types was programmed into MATLAB, as well as the optical data for different kinds of microorganisms. Extinction spectra were simulated using many different size distributions; these distributions were centered at particle sizes typical of microorganisms, liquid clouds, and ice clouds.
Many experiment were carried out in order to analyze the effects of different variables on the resulting extinction spectra. These experiments and their results are detailed in our second poster, entitled “Direct Optical Detection of Microorganisms in Exoplanet Atmospheres: Models & Results.
