According to a new search for extraterrestrial intelligence (SETI) study, the way to find intelligent life is to look for extraterrestrials that are also looking for intelligent life. I’m talking about us, despite the fact by all accounts, this Super Tuesday could see Donald Trump run away with a number of states.
Aliens will also be looking for aliens even if that just means us
NASA’s Kepler spacecraft has proven itself quite adept at finding other worlds. Since its launch in 2009, the spacecraft has discovered well over a 1,000 worlds by observing how the light dims as a planet orbits in front of its parent star (Sun, in the case of Earth).
This understanding has led René Heller, an astronomer at the Max Planck Institute for Solar System Research in Göttingen, Germany to suggest that if intelligent life is to be found, the search should focus on exoplanets that would be able to see Earth pass before the Sun. Essentially, Heller says that we should each focus our searches on the “transit zone.”
“They have a higher motivation to contact us, because they have a better means to identify us as an inhabited planet,” Heller says.
In the April issue of Astrobiology, both Heller and Ralph Pudritz, an astronomer at McMaster University in Hamilton, Canada, argue that this transit zone is where the $100 million Breakthrough Listen project, should focus its attention: stars where planets transit before them.
These stars that see this transit are located in a band of space that exists based on a projected plane of the Solar System out into the cosmos. Unfortunately, in the minds of the pair of astronomers, the Breakthrough Listen project is focused on the center and plane of our galaxy not the plane of the solar system.
The two admit, that the idea to search the “transit zone” is not unique to them but given what is being gleaned by Kepler, they do believe that this idea first posited in the 1980s is the route to go.
Transit zone is a fairly small or at least narrow
By focusing on the transit zone, extraterrestrials wouldn’t have to scan too much space as Earth’s solar transits occur in a specific space made even smaller if referring to the transits where the Earth passes the Sun within a half a solar radius to the center of the Sun. It should be mentioned that these aliens would also need something similar to the Kepler to find us.
To refine their search area that the two believe we should be looking, the astronomers used data from the Hipparcos satellite and identified 82 Sun-like stars withing 1,000 parsecs of earth. Knowing that we’ve not discovered all of the Sun-like stars within 1,000 parsecs of Earth, the two settled on a number somewhere between known stars and ones that likely exist. It’s hardly great science, but I’m willing to trust them. They determined that there are around 10,000 stars where we should be looking for transits. It’s in these areas that the two also believe communications from intelligent denizens of other planets that have seen the Earth’s transit would be “beamed.”
Heller believes that any planets that are orbiting the Van Maanen’s Star, only 4 parsecs away, would certainly seen the Earth’s transit if looking.
“If any civilization survived the death of their star, they could see us transiting our own Sun,” says Heller.
It’s expected that the Gaia satellite will likely discover most of the stars in the Earth’s transit zone in the next five years. Gaia is operated by the European Space Agency (ESA). Once that is done, the pair plan to concentrate their efforts on looking for exoplanets orbiting these stars and find the aliens that are trying to find us.