Are we alone? If there are aliens out there would they be able to detect our presence? It’s a question which we often ask ourselves. However, a team of astronomers has identified 2,034 star systems located at 326 light-years from Earth, that might have the best location to detect signs of intelligent life on Earth.
According to the data from the Gaia space observatory, there is an ongoing project to map the Milky Way in three dimensions with the highest precision to date, to find out if any alien civilizations out there could find humanity with the tools that we use to find exoplanets.
For the same purpose, we have several tools but the most productive technique is something we know as the transit method. Moreover, if an exoplanet happens to have an atmosphere, the way in which some wavelengths are enhanced or absorbed by the atmosphere can reveal its composition, also some gases can indicate signs of life.
The Gaia data has allowed astronomer Lisa Kaltenegger of Cornell University’s Carl Sagan Institute and her team to search for star systems that may have been able to do the same observation on us, this vantage point is known as the Earth Transit Zone.
“We wanted to know which stars have the right vantage point to see Earth, as it blocks the Sun’s light,” Lisa said. “And because stars move in our dynamic cosmos, this vantage point is gained and lost.”
According to their analysis of the Gaia data, the researchers worked out that there have been 1,715 star systems in the Earth Transit Zone in the last 5,000 years that could have detected biosignatures of the human race, as technology advanced, moreover an additional 319 star systems will enter the Earth Transit Zone in the next 5,000 years.
“Gaia has provided us with a precise map of the Milky Way galaxy, allowing us to look backward and forward in time, and to see where stars had been located and where they are going,” said astrophysicist Jackie Faherty of the American Museum of Natural History.
“Our analysis shows that even the closest stars generally spend more than 1,000 years at a vantage point where they can see Earth transit,” Kaltenegger said. “If we assume the reverse to be true, that provides a healthy timeline for nominal civilizations to identify Earth as an interesting planet.”
“We don’t know yet how likely it is to have life on planets or how likely it is that curious technological civilizations evolve from there,” Kaltenegger added. “We don’t know at all if there is life out there in the cosmos, but we are on the verge of finding out.”
As we all know, that searches for alien civilizations have so far revealed no signs whatsoever. But, if given enough time, and luck, it may be possible to locate our cosmic neighbors.
“One might imagine that worlds beyond Earth that have already detected us, are making the same plans for our planet and solar system,” Faherty said. “This catalog is an intriguing thought experiment for which one of our neighbors might be able to find us.”
If you want to know more, you can read the full research published in Nature.