Gabriel Gatehouse looks around the giant radar telescope in Ukraine that will be beaming out Bebo messages.
Messages have been sent to a planet 20 light years from Earth in the hope they will reach intelligent alien life.
Some 501 photos, drawings and text messages were transmitted on Thursday 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 12m users to send in missives they would like extra-terrestrials to receive.
The beamed messages will be sent 120 trillion miles into space
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 travel 120 trillion miles into space after being sent via high-powered radio waves from the National Space Agency of Ukraine's RT-70 radar telescope in Evpatoria.
Here we are
After being launched at 0600 GMT Bebo's mission commander Oli Madgett said the message "passed the Moon in 1.7 seconds, Mars in just four minutes and will leave our Solar System before breakfast tomorrow".
Organisers hope the hi-tech package will reach its target - the planet Gliese 581C - in early 2029.
Bebo spokesman Mark Charkin said: "A Message From Earth presents an opportunity for the digital natives of today... to reconnect with science and the wider universe in a simple, fun and immersive way."
If anybody's out there and they find that signal, they at least know it that... there must be a planet with some pretty clever things on it
Seth Shostak SETI astronomer
Seth Shostak, a senior astronomer from the Search for Extra Terrestrial Intelligence Institute in California, said whether aliens who might receive the messages would understand them was beside the point.
"The point might simply be: well, here we are; we're clever enough to build a radio transmitter," he told the BBC.
"So if anybody's out there and they find that signal, they at least know it that, in the direction of that star system over there, there must be a planet with some pretty clever things on it."
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