A total eclipse thermochromic stamp that changes when you touch it

The August 21 eclipse is being commemorated by the US Postal Service with a new stamp printed with thermochromic ink; when you rub the stamp the image transforms from an image of the 2006 total eclipse as shot from Jalu, Libya, to a photo of the full moon, both taken by Fred Espenak, aka Mr. Eclipse, of Portal, AZ. (more…)