Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., said Cassini will be taking pictures of Earth for about 15 minutes starting at 5:27 p.m. EDT Friday.
"Cassini has photographed Earth before, but this will be the first time Earthlings know in advance their picture will be taken from a billion miles away," Spilker said. "We hope that people around the world will go outside to wave at Saturn while the photo-shoot is under way.
"I am excited about this rare opportunity to send photons of all of us waving at Saturn," she said. "I am encouraging my family and friends to wave at Saturn on that day also."
NASA said the Americas will be facing Saturn at the time of the photos.