Achoo! There's – achoo! – pollen around. Runny eyes, itchy nose, and pollen coronas. Achoo!
Hang on. Wait a minute. What's a pollen corona?
It's kind of like an ice halo, but it's the alignment of pollen grains in the air that cause the effect, not ice crystals. Ice halos are also big and easy to see, but pollen coronas are much smaller, fainter and closer to the Sun or Moon. This closeness means they get swamped by sunlight or moonlight.
Astronomer Bob King suggests getting something solid in front of you that will block the bright disc of the Sun or Moon, and then letting your eyes get used to the dark. “Look for an oval glow, sometimes tinted with rainbow colors, right up next to the Moon or Sun's edge.†A full Moon in June is a good time to look, he says.
And
here's a colorful pollen grain lunar corona.