Hello r/science! From space, NASA has been keeping an eye on Earth’s energy supply from the Sun for more than 40 years. For a long time, scientists assumed the Sun’s energy output was unwavering, they called it the ‘solar constant.’ But, by the 1980s, we learned that solar energy reaching Earth was not constant, and fluctuates with solar activity on a roughly 11-year cycle. This change in the total solar irradiance is just one of the Sun’s influences on Earth’s atmosphere, weather, and climate. We are here to talk all things TSIS-1 and Sun-Earth interactions. Joining you today will be: Peter Pilewskie, professor of ocean and atmospheric science, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder Dong Wu, Earth scientist NASA Goddard Space Flight Center Doug Rabin, solar physicist at NASA Goddard Space Flight Center Jae Lee, Earth Scientists at NASA Goddard Space Flight Center Candace Carlisle, Project Manager TSIS-1 at NASA Goddard Space Flight Center Charles Ichoku, NASA Earth Scientist We’ll be back to answer your questions at 3 pm ET (12 PT), Ask Us Anything!