Humans should start sending messages to planets in habitable zones in the hope that alien life-forms might hear us, scientists have said.
Space experts at the Search for Extra Terrestrial Life (SETI) project said the time has come to stop passively listening for signs of intelligence in other worlds and actively start seeking contact.
SETI was founded 20 years ago to monitor the cosmos for signals of alien life and involves astrophysicists from institutions like Harvard University and the University of California. However as early 1960 scientists were scanning space for clues to other civilizations.
Douglas Vakoch, the Director of Interstellar Message Composition at the SETI Institute, said we should now start devising a message to send to planets which have recently been discovered in the "goldilocks zone" – areas of space where it is neither too hot nor too cold for life to exist.
"For over a half century, scientists engaged in the search for extraterrestrial intelligence have sought evidence of the existence of other civilizations by searching for intentional radio signals," he said
"As we move into the next half century we should expand our strategies, so we are not only passively listening, but also transmitting intentional, information-rich signals.