I actually stole it from a friend of mine, who works at Fermi and is a NASA solar system ambassador. He gives astronomy talks at midwest SF cons. If you saw the FNAL pajama party for CERN, he's the one wearing the PJs with the rad symbols all over them.

Fred

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"For shame, gentlemen, pack your evidence a little better against another time."
-- John Dryden, "The Vindication of The Duke of Guise" 1684