Seeing during the Transit of Mercury

Bad seeing in a turbulent atmosphere at the start of the Mercury transit on May 9, 2016.

http://www.astropix.com/Mercury_Transit_Seeing.html

“Seeing” is the astronomical term that describes how steady the atmosphere is. It’s not how clear the atmosphere is.

Wind, turbulence, and temperature gradients in the Earth’s atmosphere affect light as it passes through. It’s like looking through heat waves rising off the pavement in the summer.