In the summer, Bebo teamed up with production company RDF Digital to launch the A Message From Earth project.
The search then began for the 500 Bebo users, selected by a vote, who would get to send their messages, including pics, into space.
Well the digital capsule containing the messages is now rocketing to the planet Gliese, which is 20.5 light years away, thanks to the National Space Agency of Ukraine's RT-70 radio telescope.
Amongst the goodies that aliens might find are messages from regular Bebo users, including Radio One DJ Scott Mills and Britain's Got Talent winner George Sampson.
Bebo Mission Specialist Alice Levine wrote on the site today: "After months of planning and preparation, your messages have started their epic journey across the solar system and beyond".
"All 501 were broadcast from the Space Agency of Ukraine this morning from the giant RT-70 telescope."
"You guys have officially made history by creating the first democratically chosen message to be sent into space. After 1.7 seconds your messages had passed the moon and now they are on their way to Saturn."
The messages are due to reach the planet by spring 2029.