A team of scientists in Switzerland has claimed that aliens or extra-terrestrials would have been dead by the time their messages reach us since the huge distance barrier between earth and outer worlds will make the contact unlikely.
The scientists believe that extra-terrestrials will make use of radio signals to contact us which will travel at a speed of 300,000 kilometers per second. While this speed may sound fast, in cosmic terms, it is extremely low.
The study report is now published in the pre-publication site arXiv.
Aliens will not pose a threat to us
The researchers believe that most of the civilizations will not survive for more than 100,000 years, and as a result, a possible contact between humans and extra-terrestrials will not happen at any cost. It should be noted that humans have been sending radio waves for the past 80 years, and they have traveled just .001 percent of the galaxy in this time. Our milky way galaxy alone spans across more than 100,000 light years, and this indicates the vastness of our Universe.
"If the civilization emitted from the other side of the galaxy when the signal arrives here, the civilization will already be gone," told Dr Claudio Grimaldi, the lead researcher from the École Polytechnique Fédérale de Lausanne, Switzerland to Science News.
During the study, researchers made use of Drake's equation which detects the number of civilizations which exist in Milky Way. The researchers claimed that part of our Milky Way would be filled with ghostly signals which might be sent by extra-terrestrial life forms millions of years ago. Even after the civilization dies off, the signals they had sent continue traveling like concentrated ripples on the pond, and finally, it may reach us too.
The dramatic moment in which an astronomer detected a radio signal
In 1977, astronomer Jerry Ehman spotted a powerful radio signal which lasted for 72 seconds. Upon receiving this signal, Ehman became very excited, and he wrote Wow next to the data obtained. Even though the signal came from Sagittarius, it did not match any cosmic object. However, conspiracy theorists strongly believe that the 'Wow' signal was sent by intelligent life forms from outer space.