Studies found that aliens are only interested in making contact with technologically advanced planets, while technology on Earth is not as advanced.
In a study published on arXiv, an Astrophysicist at the Hebrew University of Jerusalem said life on other planets and galaxies has undergone many revolutions. Therefore, aliens might be more interested in planets with advanced technology.
Aliens go on long-distance space travel
The study examines the Fermi paradox. Well, this paradox says that given the age of the universe, it is very likely that intelligent aliens will undertake long-distance space travel from now on.
In this way it is possible for them to visit the earth. Previously, experts argued that aliens may have visited Earth in the past, before humans evolved, and were able to document those visits.
Another possibility is that long-range space travel could be more difficult than thought. As a result, the journey becomes a challenge for the aliens to get to Earth.
On the other hand, it could also be that aliens made a conscious decision not to explore the cosmos. In his new study, however, Wandel explains that life forms are extremely common in the Milky Way.
Aliens are more interested in technological signs
Intelligent aliens are more interested in technological clues. However, technology signals can be difficult to spot.
In fact, the Earth has been sending out detectable signals from space in the form of radio waves since the 1930s.
Theoretically, these signals have detected about 15,000 stars and planets orbiting them. However, that is only a fraction of the 400 billion stars in the Milky Way.
It takes time to reply to alien messages
Wandel explains that it takes time for all messages from aliens to travel back to Earth. Therefore, only stars have had time to respond within 50 light-years since Earth began sending signals beyond the planet.
Although there are more than 100 million technological planets or intelligent civilizations in the Milky Way, it is possible that Earth’s signal has not yet reached the planets.
However, over time, Earth will be emitting more and more radio waves, making it more likely that Earth’s technology signals will find aliens.
Amri Wandel is a senior scientist in Astrophysics at the Racah Institute of Physics at The Hebrew University of Jerusalem. Wandel is an expert in Astrobiology and chairman of the Israeli Association of Astrobiology and Early Life. He is also president of the International Academy of Sciences San Marino.