Technische Universität Berlin
Hardenbergstr. 36A, D-10623 Berlin
Perhaps the most intriguing question that has mystified humans for centuries is “are we alone in the Universe?” As we move forward with observations of exoplanets, we must further develop dynamical and chemical models as well as laboratory experiments in order to analyze, compare, and understand planetary environments in various systems and their implications for the potential habitability of other worlds. Focusing exclusively on life as we know it today would be anthropocentric, as planets with more suitable conditions for life could exist. Such conditions are termed ‘super-habitable’.
So far, there has only been sparse focus placed on planets in the habitable zones (HZs) around K-dwarf stars as good candidates for the search of extraterrestrial life. These stars, however, have longer stellar lifetimes compared to our Sun and provide favorable planet/star contrast ratios given by a weaker stellar luminosity. They also host planets with shorter orbital periods which allow for more frequent transit observations and provide a more benign UV environment for their exoplanets in comparison to our Sun and to their cooler counterparts, M-dwarf stars. As such, they should be the future focus of exoplanetary studies.
Fig. 1: Kepler-62f with 62e as Morning Star. This is an artist's
concept of a planet orbiting in the habitable zone of a K star
(Credits: NASA Ames/JPL-Caltech/Tim Pyle).
As a Ph.D. student, I am 1) looking into Earth’s natural history of varying habitability in order to calibrate and provide a framework for superhabitability, 2) using an Environmental Simulation Chamber facility to experimentally determine the responses of a microbial consortium and key Earth organisms (such as cyanobacteria, fungi, plants and E.coli) to super-habitable conditions, and 3) using theoretical climate-chemistry models to determine how life affects the biosignatures of a super-habitable planet around a K-dwarf host star by providing transmission spectra, atmospheric compositions etc. and using these results to provide a guide for space-based transit observations of extrasolar potentially habitable planets.