Cassini turns its camera toward Earth; Saturn's shadow makes it possible
Cassini had orbited Saturn since 2004. On July 19, 2013, imaging team leader Carolyn Porco positioned the spacecraft to catch Saturn eclipsing the sun, a moment of ideal lighting that also put Earth in the frame, 1.44 billion kilometers away. Unlike two earlier Earth photos Cassini had taken in 2006 and 2012, this time NASA told the public in advance. Millions looked up and waved at Saturn.
NASA asked Americans to look up and wave during a routine imaging pass. Americans were told in advance to look up and wave, then watched their own planet appear as a speck beside Saturn's rings on the front page of The New York Times. The Library of Congress later folded the image into Carl Sagan's archive. The Library of Congress ceremony explicitly linked the 2013 image to Sagan's 1990 'Pale Blue Dot' photograph.
QWhat happened to the 1,600 photos people submitted for 'Wave at Saturn'?
The 1,600 submissions from the public campaign were compiled into a separate collage image, released the same day as the official Cassini mosaic, November 12, 2013. It stood as a kind of companion piece, a portrait of the people looking up rather than the planet they were standing on.
QWhat was beamed into space alongside the Cassini image release?
A contest called 'Message to the Milky Way' ran in connection with the event, inviting entries meant to represent humanity to any listener beyond Earth. The winning submissions were transmitted outward using the Arecibo Radio Telescope in Puerto Rico, an instrument normally used to receive signals rather than send them. The messages are still traveling outward, with no star system close enough to receive them soon.
QWhy did the Library of Congress get involved in an image from a Saturn probe?
The library had recently acquired Carl Sagan's personal papers, and it held a ceremony specifically to dedicate the Cassini photograph to him. The connection ran through Sagan's own 1990 'Pale Blue Dot' photograph, taken by Voyager 1 looking back toward Earth from the outer Solar System. Cassini's 2013 portrait echoed Sagan's Voyager photo, taken decades earlier from much farther away.
