The fact was announced by The Guardian with reference to a study published on June 23 in the Nature journal.
Scientists wanted to find out what planets intelligent alien civilizations could observe humans from. In a recent study, astronomers identified nearly 1,800 star systems in our space region, where it was possible for aliens to discover our planet over the past 5 thousand years by looking at how the Earth passes over the Sun and obscures part of its light.
There are forty-six star systems located in the right position to observe our planet that are close enough for their planets to intercept radio waves and TV broadcasts, a clear sign of human existence.
Researchers estimate that there are 29 potentially habitable planets that have let their inhabitants observe humans. They might intercept radio broadcasts and conclude that intelligent life exists on Earth.
Astronomers on Earth already discovered thousands of planets located outside our solar system. Nearly 70% of these planets were found while they were passing in front of their stars, blocking some of the light that reached the scientists’ telescopes