NASA’s Solar Dynamics Observatory (SDO), best known for cutting-edge images of the sun, has made a discovery right here on Earth.
“It’s a new form of ice halo,” says atmospheric optics expert Les Cowley of England. “We saw it for the first time at the launch of SDO–and it is teaching us new things about how shock waves interact with clouds.”
Ice halos are rings and arcs of light that appear in the sky when sunlight shines through ice crystals in the air. A familiar example is the sundog—a rainbow-colored splash often seen to the left or right of the morning sun. Sundogs are formed by plate-shaped ice crystals drifting down from the sky like leaves fluttering from trees.
Last year, SDO destroyed a sundog—and that’s how the new halo was discovered.
Author: Dr. Tony Phillips