Video from Endeavour’s Monday morning launch clearly showed a white spot on the leading edge of the left wing – a spot that should be dark gray. The irregularity is visible in video of the orbiter on the pad before launch, but seems extra bright in footage taken from the shuttle’s external tank, eight minutes into flight.

“We saw it in the video, and the teams will look at it some more,” Bill Gerstenmaier, NASA’s director of space operations, told FOX 13’s Warren Elly. “I don’t think it’s anything more than just the difference in lighting.”