PASADENA, CA: When the Mars Exploration Rovers were launched last year, The Planetary Society placed on board hidden messages as a public involvement activity in their educational Red Rover Goes to ...

Enjoy an easy set up for your elf with these free printable Elf on the Shelf Detective Props and message decoder. Dress up your elf with elf sized props, and decipher clues with the message decoder.

One downside of the method is that each molecular message can only be read once, since decoding the polymers involves degrading them. The decoding process also takes time -- around 2.5 hours for the ...