DETROIT — For many of us, taking in our neighbors’ outdoor holiday lighting displays and other decorative touches is as much a part of the season as exchanging gifts and singing Christmas carols.

Massive crowds joined Santa as he counted down to the lighting of Detroit’s 66-foot Christmas tree on Friday. As the tree came to life with 25,000 LED lights, cheers erupted in Campus Martius Park.

The colorful northern lights may reveal themselves to a wide swath of Americans Friday night due to an impending solar storm ...