Teresa Palmer & Penn Badgley: 'Parts Per Billion' Filming in Detroit

Penn Badgley and Teresa Palmer walk back to their trailers after filming a few scenes for Parts Per Billion on Wednesday afternoon (December 5) in Detroit, Mich.

The actors, both 26, bundled up in warm coats as they shot scenes outside in the cold. At one point, Teresa and Penn, were both down on their knees in the frosty grass.

PHOTOS: Check out the latest pics of Teresa Palmer

Parts Per Billion tells the story of three couples dealing with their relationships during war, and also stars Frank Langella, Gena Rowlands, Rosario Dawson, and Josh Hartnett.

15+ pics inside…