On August 21, millions in the US will witness a rare celestial event. For the first time in 38 years, the moon will completely block the solar disk for a few minutes, creating a total eclipse of the sun.
To mark the historic event, the United States Postal Service is issuing an inspired postage stamp with a special trick.
Conceived by graphic designer Antonio Alcalá, the stamp features two layers of photographs. The first image depicts a picture of a total eclipse observed in Libya in 2006 by renowned astrophysicist Fred Espenak. Then, through the magic of thermachromic printing, an image of a full moon emerges when the warmth of your finger touches the black dot.
The commemorative stamp uses special temperature-sensitive inks that have also been used in mood rings, food labels, and color-changing Coors Light beer cans. On the back of the sheet of stamps is a map of the eclipse’s 70-mile shadow path, which will traverse 14 states as it moves east, from Oregon to South Carolina.
The USPS commissions graphic designers, illustrators, and designers to develop around 25 new postage stamps every year. The postal service has released several inspired designs this year, including a charming skywriting “Love” stamp by graphic designer Louise Fili and a special philatelic tribute to American Sign Language arts teacher Robert Panara.
The Total Solar Eclipse stamps go on sale on June 20. They’ll be released as “forever” stamps, meaning they’ll be accepted as standard postage on first-class mail even when rates go up.