New stamp celebrates upcoming solar eclipse with heat-reactive transformation

On Monday, August 21st, the continental US will experience its first total solar eclipse since 1979. And to get the country prepared, the Postal Service is releasing a heat-reactive commemorative stamp. The stamp is printed using thermochromic ink, and when rubbed using fingers or thumbs will react to body heat, changing from an image of a total solar eclipse to a picture of the Moon. And, if you’re someone who loves to get your astronomical news from stamps, the back of the will also show