Red River

This was the final screen role for Guy Madison.

Since there is no "Errors in astronomy" category, I guess this goes here. When Gregory Harrison (Cherry Valance) is wooing Laura Johnson (Kate) at night under a tree with a canopy you couldn't possibly see through, while she's holding a child, and she says she has to go, and he points out the big dipper to her to get her to stay. But the view shows a thick patch of stars with no pattern. Not the Big Dipper, which is in a northern region with much fewer stars where it's easily visible year-round if it's view-able.