UFO hunters have taken to poring over the extensive backlog of images snapped by astronauts during shuttle flights over the last 30 years. In the photo posted here, NASA itself describes an object as "unknown." What is it?

The photo, taken during shuttle mission STS-32 in January, 1990, is black, oblong and strangely shaped. The photo was taken as astronauts trained cameras on the Earth, tracking a satellite about to decay in orbit and burn up on reentry. It would seem the astronauts would be able to identify such an object, so why can't they figure out what this unidentified flying object is.

The UFO doesn't resemble any of the classic shapes usually associated with "alien" spacecraft, being particularly non-aerodynamic looking.

Credit to: Jake Walker