PICK OF THE WEEK: If you’re among the hordes of football fanatics who can’t get enough of your favorite sport, huddle up at the Minnesota History Center. “Gridiron Glory: The Best of the Pro Football Hall of Fame” opens Saturday. The exhibit includes more than 200 items, among them Knute Rockne’s helmet and a jersey worn by Jim Brown (if you have to be told who these people are, this show is probably not for you). There’s also a football that was thrown by Brett Favre. (Don’t worry, it’s from when he played for the Vikings, not that other team on the wrong side of the St. Croix River.) The exhibit continues through Jan. 15. Admission is $20 for adults and $10 for ages 5 to 17, with a $5 discount for members of the Minnesota Historical Society. (tinyurl.com/gv6qxl7)

Cheat sheet: The autumnal equinox marking the start of fall is on Thursday.

• It’s not an entire day, although calendars list it that way. It’s actually just one moment. This year it will take place at 9:21 a.m. (Twin Cities time).

• In theory, it’s one of only two times each year (the spring equinox being the other) in which day and night are exactly equal. We say “in theory” because the rays from the sun refract, producing light before sunrise and after sunset.

• The full moon closest to the equinox is called the harvest moon. Although that’s well known thanks to the classic tune “Shine on, Harvest Moon,” all full moons have names. The harvest moon is followed by the hunter’s moon, beaver moon and cold moon. And so on.

Day by day: Sunday is national One Hit Wonder day. It refers to musicians who have had only one hit song, not the Twins’ batting order. (OK, that was a cheap shot, but when you have the worst record in the league. …)

Recommended reading: The Ivey Awards honoring the best in local theater are being presented Monday evening. Catch up with all the winners in Tuesday’s Variety.