While signals from extraterrestrial civilizations to reach Earth, it is likely that by this time all the aliens have long been extinct. To this conclusion came a group of American astronomers under the guidance of the Swiss researcher Claudio Grimaldi, decided to revisit the famous Drake equation, a formula designed to determine the number of extraterrestrial civilizations in our galaxy with which humanity has the chance to make contact.
In their paper, the researchers calculated the area of the region of the galaxy, through which must pass the alien signals. According to Drake himself, civilizations are born and die at a constant speed. The death of civilization is stopped, and transmission of messages. But already sent signals continue their journey through the galaxy, as the circles spread on the water. In the end, a large part of the galaxy is filled with messages from dead aliens.
The diameter of the milky Way is hundred thousand light years, while the Solar system is about 26 thousand light years from the galactic center. Scientists believe that the most advanced civilizations capable of sending radio signals, do not exist longer than a hundred thousand years. Therefore, the chances of getting the message of aliens, is still broadcasting at present, very small. The same humanity sends signals into space for nearly 80 years, therefore, radio waves from Earth have covered less than 0.001 percent of the area of the galaxy.
“If civilization living on the other side of the galaxy, sends a message, by the time this message gets to us, this civilization will die out,” says physicist Claudio Grimaldi of the Federal Polytechnic school of Lausanne.