To celebrate the August 21 total eclipse, the United States Postal Service has released a first-of-a-kind stamp that uses thermochromic ink to transform from an image of the eclipse to the moon using the heat of your finger. The back of the sheet of stamps shows the eclipse’s 70-mile-wide path (it will cross more than 1,100 cities) all the way from Oregon to South Carolina.
A total eclipse of the sun occurs when the moon completely blocks the sun, casting a shadow on Earth. The eclipse this summer will sweep across the entire country—the first time this has happened since 1918. A total eclipse was last seen in the U.S. in 1979, but only in the Northwest.
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“With the release of these amazing stamps using thermochromic ink, we’ve provided an opportunity for people to experience their own personal solar eclipse every time they touch the stamps,” Jim Cochrane, Chief Customer and Marketing Officer of the United States Postal Service, said in a release. “As evidenced by this stamp and other amazing innovations, the Postal Service is enabling a new generation to bridge the gap and tighten the connection between physical mail and the digital world.”