Warning: I used a couple bad language words.
Moon Poop
Description: it is, in fact, a tightly sealed container holding the organic residue of the first human solid excrement generated on Earth’s moon, where said excrement was exclusively derived from food grown and prepared on the moon. If you’re wondering how people could possibly know that, it’s probably because this excrement (and no other) glows silver-white, with a pulse that waxes and wanes with the lunar cycle. Needless to say, Moon Poop tests as being of esoteric origin. It has no other known properties than its ability to drive physicists mad with its mere existence.