Kelly Chance is a Senior Physicist at the Smithsonian Astrophysical Observatory and the Principal Investigator for the NASA/Smithsonian Tropospheric Emissions: Monitoring of Pollution (TEMPO) satellite instrument that is currently being built to measure North American air pollution, including the U.S., Mexico, Canada, and Cuba at high spatial resolution, hourly from geostationary orbit (tempo.si.edu). He has been measuring Earth's atmosphere from balloons, aircraft, the ground and, especially, from satellites since receiving his PhD in Chemical Physics from Harvard in 1977. Measurements include the physics and chemistry of the stratospheric ozone layer, climate-altering greenhouse gases, and atmospheric pollution. For many years he taught the course "Spectroscopy and Radiative Transfer of Planetary Atmospheres" at Harvard. Randall V. Martin is Professor at Dalhousie University, and Research Associate at the Smithsonian Astrophysical Observatory. His degrees are from Cornell University (B.S.), Oxford University (M.Sc.), and Harvard University (M.S., Ph.D.). He has taught Radiative Transfer at Dalhousie for several years. His research is at the interface of satellite remote sensing and global modeling, with a focus on characterizing atmospheric composition to inform effective policies surrounding major environmental and public health challenges ranging from air quality to climate change. His professional honors include the Langstroth Memorial Teaching Award, an NSERC Steacie Memorial Fellowship, and selection to the Royal Society of Canada.