Use the Exploratorium exhibit Cells to Scale to visualize how small a coronavirus really is and investigate the implications of its small size.
Find out more about the science of COVID-19 with the Exploratorium Learning Toolbox.
Update: Increased understanding of the coronavirus that causes COVID-19 has shown the virus can persist in very small respiratory droplets that stay suspended in the air. People can be infected from inhaling these droplets, so N95 masks are now recommended for everyone as the best way to prevent transmission.