My buddy Mitch, N8XS, recently took a photo of the moon from southwestern Ohio using a Nikon P1100 bridge camera. It’s a 3-second exposure and he was resting the body on the neighbor’s mailbox. I think it turned out great.

Crescent moon photographed with a Nikon P1100, showing the dark oval of Mare Crisium near the terminator line
Taken with a Nikon COOLPIX P1100, 3000mm equivalent zoom

When he sent that to me we chatted for a moment trying to figure out one specific area. Then Mitch asked Claude about the big basin near the terminator. Claude’s reply was as much astronomy education as I’ve had this decade:

“That’s Mare Crisium, not technically an impact crater but a lunar mare (basalt-flooded impact basin) — it just looks like a giant crater because of its smooth grey floor and clearly raised rim of highlands. It’s one of the most recognizable features on a young crescent moon like this since it sits somewhat isolated from the other maria, right near the terminator.

Diameter: ~555 km (about 345 miles) — roughly oval, closer to 570 x 620 km if you include the full basin.

I actually cross-checked this against your photo: I fit a circle to the Moon’s limb in your image (~2376 px diameter corresponding to the Moon’s real ~3475 km diameter, so ~1.46 km/pixel), then measured the dark “crater” feature at roughly 430-500 px across — that lands right around 600-700 km, which is a solid match for Mare Crisium once you account for foreshortening near the limb (features get visually compressed the closer they are to the edge of the disk, so its true diameter reads a bit smaller than it would face-on).

Nice catch on your P1100 — that’s a really crisp capture of the terminator detail for a bridge camera shot.”

I waited for Prime Day deals, then I ordered a P1100 of my own.