SOLARIS is used in the ocean to make measurements of a fleetingly scarce compound called superoxide, a reactive oxygen species. SOLARIS utilizes the property chemiluminescence, a chemical reaction that produces light. The sensor SOLARIS enables scientists to bring the high-precision analyses of a chemistry laboratory to depths of up to 4500 meters to better understand the chemical dynamics of reactive oxygen, which researchers hope to use in understanding the corals' abilities to defend against pathogens and stress.