In this episode, Dr. Svetlana Shkolyar of the Goddard Space Flight Center joins us to discuss her recent paper on specific issues and 'cautionary tales' of biosignature research. Biosignatures, are possible signs of life, or biotic activity, on a planet. We search for them using spectroscopy, a form of light detection that separates out molecules based on the wavelength. Dr. Shkolyar's paper focuses on one particular molecule, cerium 3+. The reason is because this molecule tends to look exactly like the biosignatures we associate with life. In this sense, cerium 'mimics' biosignatures, and could lead scientists to conclude we found life when we actually have not.