The newest Forever stamps were unveiled Thursday, and they're pretty high-tech – for stamps anyway.
At first sight, the stamps appear to show a simple black circle. That circle is actually supposed to be a total solar eclipse – when the moon passes between the Earth and the sun and blocks out the light.
But if you touch the stamp, the black circle will transform into the image of a moon.
According to the United States Postal Service, this will be the first time thermochromatic ink has been used in postage stamps. That's what allows the image to change like that. The moon will disappear again as the stamp cools – so you can make it appear and disappear as many times as you like.
The new Total Solar Eclipse stamps are being released in celebration of the Aug. 21 eclipse. Unfortunately, Minnesota will only see a partial eclipse. Here's a map showing where the eclipse will be visible.
The 49-cent Forever stamps will be available on June 20.