Looking for Life by Looking for Life

Potential plumes of water vapor were detected erupting from Jupiter's moon Europa by the Hubble Space Telescope earlier this year. (Image: NASA/ESA/W. Sparks (STScI)/USGS Astrogeology Science Center) The search for life beyond Earth has inspired many strategies, from examining microfossils with elemental analyzers, to sequencing putative genetic material, or studying the composition of distant exoplanets. But a recent paper from Jay Nadeau, a Scientific Researcher at the California Institute of Technology, proposes a surprisingly new approach of looking for life by, well, looking for it. Nadeau and her colleagues suggest that “rapid and meaningful” cell movement is “an unambiguous biosignature that makes no assumptions about the chemical composition of the organisms under study.” They propose using a microscope to track particles moving through a field of view, but the two qualifiers are critical: after all, dust grains that move by diffusion, or are pushed by wind or water currents, can ...