Something in Space Has Been Calling Earth to Itself Every 22 Minutes for the past 35 Years!

A mysterious signal has been reaching Earth every 22 minutes for over 35 years. This signal has no known natural source and repeats itself with a regularity that makes it particularly mysterious and unique. The source of this signal has been sought several times, but to this day it remains unclear whether it is a natural signal, a previously unknown phenomenon or a message from other life forms!