In 1977, NASA launched Voyager 1 and Voyager 2 into the vastness of space. Each carry with them a golden record containing images and sounds meant to depict Earth; if an alien civilization ever discovers either Voyager probe, they could lead back to Earth, or at least provide a small snippet of our civilization. Almost 20 years later, NASA considered sending a similar archive along with its Cassini probe which is now in orbit around Saturn. Cassini's archive would be A Portrait of Humanity, a stereo pair of images meant to depict, in a single 3D snapshot, the breadth of human life.
The Portrait was meant to travel to Saturn's moon Titan on NASA's lander. NASA's mission went ahead as planned--Cassini was launched in 1997, and the Huygens craft successfully landed on Titan in 2005. But the images were never completed or launched with the mission. Jon Lomberg, who designed the Voyager Record for NASA, was also behind the Portrait of Humanity. He wrote an interesting history of the project that highlights its purpose and, most importantly, how it different from the records sent with Voyager and the CD-ROM Visions of Mars.
"Unlike the Voyager Record it was not intended to leave the solar system to be found by the crew of an advanced starship," writes Lomberg. "Unlike Visions it was not for humans in the next few centuries. Its fate would have been to remain on the surface of Saturn's moon Titan, waiting for eons of time against the slim chance that life might someday appear on that strange world, or that some other space traveler might visit Titan and find it. The image, inscribed on a diamond wafer about the size of a coin, was intended to show an intelligent alien on Titan viewer a little about our bodies, about our relationships with each other, and about our planet."
The most complete part of the project was a photograph taken in Hawaii, which took nearly two years to envision and compose. Lomberg's writing about the photo reveals how much thought went into its composition. It represents the breadth of human ages and races, shows our bodies in various poses, and shows off Earth's oceans and blue skies in the background. Even the way people sit and stand in the photograph shows how our bodies work.
But what's really fascinating is the audience Lomberg wanted, hoped, to deliver this message to.
In 1994, he wrote a message to Carl Sagan and Louis Friedman to propose the idea and ask for their opinions and asked the rhetorical question: Who would ever see this Portrait of Humanity? In answer to his own question, he wrote this:
"Unlike Mars, Titan is unlikely to be settled by humans in the foreseeable future (though who really knows?), so a strong case cannot be made for a message along the same lines as Visions of Mars. However, a much more fantastic possibility exists for an audience.
"Our message is for the inhabitants of Titan, 5 or 6 billion years hence."
In the far future, when the Sun enters its Red Giant phase, Titan may thaw. The prebiotic organic compounds now thought to exist there may in fact evolve into biology, and that biology just might evolve intelligence. The Red Giant phase of the Sun's life can last up to a billion years, perhaps long enough for life forms to evolve and then adapt to a drop in temperature as the Sun cools and shrinks. In those far distant days the three innermost planets may cease to exist. If intelligence arises on Titan, human artifacts in the outer Solar System may be their only clue to the existence of the former children of the Sun.
Our message is for the inhabitants of Titan, 5 or 6 billion years hence."
Imagine an entire civilization developing over the course of a billion years, likely long after the Sun has been able to sustain life on Earth as we know it. Imagine that civilization developing intelligence and, one day, finding this record from Earth like a fossil--a record that's hundreds of millions of years old, sent from our planet in the year 1997. What would they make of it?
Lomberg goes on to write about the decision to send the image on a durable diamond wafer. The message was also meant to include images of our solar system to help timestamp the image and show what the solar system was like at the time of launch.
NASA wasn't paying for the record, but Lomberg found funding for the project through a Japanese investor who had helped Carl Sagan's COSMOS air in Japan. But the project eventually fell apart.
"The Portrait of Humanity foundered even before leaving the Earth," writes Lomberg. "First differences arose between Carolyn Porco (the Cassini liaison scientist) and I over the issues of who had the right to complete the project, determine its final contents, and receive credit for it. Meanwhile, NASA was growing increasingly nervous about the fact that the funding for this project had come from Fuji-Xerox, a Japanese company, who in return for their money expected--and had been promised--to have their corporate logo placed somewhere on the diamond. NASA had at first acquiesced to this, but later changed its mind...It may have been the right decision on NASA's part. By descending into conflicts about credit, money, and corporate logos, the message project may have lost its purity of motive and, in some sense, its right to fly."
NASA did, however, send a message of its own onboard Cassini. For more than a year, NASA collected signatures from around the world to include on a DVD that was placed onboard the probe. NASA put out a public call for signatures and received 616,420 postcards from around the world. The signatures from those cards were sent along with Cassini in digital form, offering a different sort of portrait of humanity. The rest of Lomberg's long, long write-up details the incredible thought and care that went into creating the photograph. It's a rare glimpse at a side of NASA history that never came to past.