Aurora Borealis

The Boston area witnessed an astronomical phenomenon extremely rare in this latitude last night: aurora borealis, or the "Northern Lights."

Caused by ionization in the upper atmosphere, the aurora appeared as greenish curtains of glowing cloud through which shafts of light passed and repassed.

Last night's display was "extraordinarily bright," and occurs very seldom in this latitude, according to Fred L. Whipple, professor of Astronomy. He said the greenish cast of the aurora was ionized oxygen, and is normal.