Comets
The Exploratorium has a exhibit to simulate the behavior of comets as they outgas when they approach the sun. The exhibit drops little chunks of dry ice onto water. The dry ice bits sublimate and release CO2 gas propelling them across the surface water.
John Christensen
NIKON CORPORATION NIKON D5000, f/2.5 @ 60 mm, 1/160, ISO 200, No Flash
© John N Christensen
