Photo detail

The sun will cross the equator heading south at 9:44 a.m. Sept. 22 marking the end of northern hemisphere summer and the beginning of fall.

Stories this photo appears in:

Tease photo

Jimmy Westlake: Autumnal Equinox

Autumn officially arrives for the northern hemisphere this year at 9:44 a.m. Sept. 22. How do astronomers determine the precise moment marking the beginning of autumn?


Use the comment form below to begin a discussion about this content.

Requires free registration

Posting comments requires a free account and verification.