Messages are being beamed to a planet 20 light years from Earth in the hope they will reach intelligent alien life.
The 500 photos, drawings and text messages were transmitted by a giant radio-telescope in Ukraine normally used to track asteroids.
The target planet was chosen as it is thought capable of supporting life.
Any reply to the messages - collated through a competition by the social networking website Bebo - would not reach Earth for 40 years.
The competition - A Message From Earth - invited Bebo's 12 million users to send in missives they would like extra-terrestrials to receive.
Topics submitted ranged from the environment, politics and world peace to family relationships and the sender's first kiss.
Having been translated into a binary format, the 500 selected will be sent 120 trillion miles into space via high-powered radio waves from the National Space Agency of Ukraine's RT-70 radar telescope in Evpatoria.
The beamed communication will pass the moon in just 1.7 seconds and take less than seven hours to leave our solar system.
Organisers hope the hi-tech package will reach its target - the planet Gliese 581C - in early 2029.