One fine day, when NASA is in preparing for early tests of the new moon lander for the Diana missions to return to the Moon, the NASA director gets word of an emergency with the lunar samples brought back from the Apollo missions.
Have they been stolen? No. Have they been destroyed? Not exactly.
They've turned to cheese.
The Moon itself, right now at quarter phase, is also looking mighty strange, with a much higher albedo than the gray, rocky world should have. Almost as if...it's also now made of cheese.
