Are we alone?
This question has plagued humankind since time immemorial. And yet, we still don’t have a conclusive answer. Despite our incredible technological advancements, we have never received a credible radio signal from, or even the teeniest trace of, extraterrestrial life beyond Earth.
The current hunt for alien life includes: the Search for Extraterrestrial Intelligence (SETI) Institute, which has scoured the skies for radio signals from intelligent beings since its founding in 1984; the Kepler space telescope, which observed more than 500,000 stars during its mission, confirming more than 2,500 exoplanets; and more recently, the James Webb Space Telescope (JWST), which just took its first direct image of an exoplanet.
Perhaps the most tantalizing potential signal from an extraterrestrial civilization is the famous Wow! Signal. This very brief, but very intense, radio signal was detected by Ohio State University’s Big Ear Radio Telescope Aug. 15, 1977, and it lasted for 1 minute and 12 seconds. The signal was so intriguing that astronomer Jerry Ehman enthusiastically wrote the word “Wow!” on the data printout.
Most now agree the Wow! Signal is unlikely to be from aliens. But in a recent May 2022 study published in the International Journal of Astrobiology, researchers identified a possible source of the Wow! Signal: a Sun-like star a bit more than 1,800 light years from Earth.
Still, the question remains: Are we alone?
“The only correct answer to this question [for now] is that we don't know,” Manasvi Lingam, an astrobiologist and Assistant Professor in the Department of Aerospace, Physics, and Space Sciences at the Florida Institute of Technology, tells Astronomy.
“With that said,” he adds, “I am hopeful of the existence of extraterrestrial life, given the number of potentially habitable worlds and the ongoing exciting research into the origin(s) of life.”
How likely are we to find life elsewhere in the universe?
Two of the most iconic insights related to the possibility of technological civilizations existing elsewhere in the universe are the Fermi Paradox and the Drake equation, which were formulated by Enrico Fermi and Frank Drake, respectively.