Post office issues stamp that transforms from solar eclipse to moon

I don't need stamps, but I'll be getting some of these solar eclipse stamps, which the U.S. Postal Service has issued to commemorate the total solar eclipse, which will sweep across the country on Aug. 21.

These first-of-its-kind Forever stamps actually changes from a solar eclipse image into the moon with simply the heat of a finger.

According to the postal service, the total eclipse stamp is the first U.S. stamp to use thermochromic ink, which reacts to the heat of your touch. When you place your finger over the black disc on the stamp, the ink changes from black to clear to reveal the underlying image of the moon. Once it cools, it reverts back to the black disc. The back of the stamp pane shows a map of the eclipse path.

The image was taken by astrophysicist Fred Espenak of a total solar eclipse that was seen over Jalu, Libya in 2006. Espenak is considered the world's leading authority on total eclipses and has seen 28 of them, according to the postal service.