Could alien signals have already reached Earth undetected?

Could alien signals have already reached Earth undetected? - If advanced alien civilisations exist and have contacted Earth, ...

If alien signals have already reached Earth, why haven't we seen them?

For decades, scientists have searched the skies for signs of extraterrestrial technology. A study from EPFL asks a sharp ...
Yahoo

Scientists Revealed Their Official Playbook for Making Contact with Aliens

Technosignatures are theoretical signs of technologically advanced alien civilizations, but so far, none of those civilizations have phoned home. Researchers from the Search for ExtraTerrestrial ...
Knowridge Science Report

If aliens already called, why didn’t we hear?

For more than 60 years, scientists have been scanning the skies for signs of intelligent life beyond Earth. Using powerful telescopes, they have searched for unusual radio signals, brief laser flashes ...
The Daily Galaxy on MSN

Alien signals could have already reached us: Why haven’t we detected them?

For decades, scientists have been actively searching for signs of extraterrestrial life. Fromradio waves to laser flashes and ...