What Does Terra and Pi have in common?

Dr. Marshall Shepherd, meteorologist and NASA astronaut, writes, “NASA has a really cool online resource in which you can test your skills by using Pi to calculate volume and water content of clouds as measured by a cloud-observing instrument called MISR (on NASA’s Terra satellite). You can even figure out how many Olympic-sized swimming pools could the cloud fill” in Forbes magazine for Pi Day, 2021.