Both the most cynical person on Earth and the world’s greatest optimist could easily look at everything around them and ask: could this truly be all there is in the universe? Whatever your reason for posing the question, you may have an answer sooner than you think — and that answer is likely to be “no.” Science writer and comedian Ben Miller posits in his book The Aliens Are Coming! The Extraordinary Science Behind Our Search for Life in the Universe that one of the most powerful forces shaping science today is the growing search for life in the universe fueled by the belief that we are not alone. He believes that because of our current technologies, we’ll know about life on the Earth-like planets closest to us within the next ten years.
It’s easy to see why he thinks so. Scientists have identified an exoplanet that they’ve described as the best candidate for life as we know it — perhaps an even more important a target for planet characterization within habitable zones in the future than either Proxima b or TRAPPIST-1, and these have also recently been discovered. Speaking of Proxima b, the James Webb Telescope is likely to give us the images that will clarify its potential for supporting life, as it will do for other exoplanets.
In recent months scientists have stated that the fast radio bursts we’ve intercepted from outer space may well be evidence of alien life. Now they’re working to discern whether alien technology could be their source. Scientists also now believe that life might exist on Europa, one of Jupiter’s four Galilean moons. Recently, NASA’s plans to send a lander in search of biosignatures that might signal the presence of extraterrestrial life within its warm core have sprung into action; Europa may be home to a subterranean ocean, making it an ideal place to search for alien life.
In 2016, researchers made improvements to the Atacama Large Millimeter/submillimeter Array that could make finding water on celestial bodies easier. These improvements were specifically directed toward the ongoing search for alien life, as was the partnership between Breakthrough Initiative to find alien life and the National Astronomical Observatories of China. China’s team uses the 488 meter (1,600 foot) FAST telescope, and now it is being used in partnership with the world’s other largest radio telescopes, including the Parkes Observatory in Australia and the Green Bank Telescope in the US, to seek out extraterrestrial life. In 2016 scientists also adopted more accurate methods for studying gravitational pull of distant stars, making it easier to gather data on the size and brightness of the star, the likelihood of water oceans, and possibility of life being present.
Stephen Hawking is one of the best-known and most reputable voices who cautions against making first contact with alien life. His argument is simply that we have no way of knowing what’s out there, and that, historically speaking, as more advanced civilizations have come into contact with less advanced cultures, the latter has typically been oppressed and aggressed against, the former seeing it as less valuable. However, it’s worth noting that when we speak historically we are, by necessity, limited to our own recorded human history. What we’re observing may not be a pattern common to all life; it may simply be a pattern common to human cultures.
In contrast, the SETI (Search for Extra Terrestrial Intelligence) Institute is populated by people who feel we have little, if anything, to lose by seeking out other forms of life. SETI has now given birth to METI International (Messaging Extra Terrestrial Intelligence), which is actively seeking out contact. Douglas Vakoch, a professor in the Department of Clinical Psychology at the California Institute for Integral Studies and the president of METI International, strongly disagrees with Hawking. He thinks it is illogical to hide our existence as a species since we have already leaked transmissions from radio and television broadcasts in the form of electromagnetic radiation for almost 100 years. Vakoch concludes that any culture with the technological sophistication to master interstellar travel can already perceive our leaked signals, and are therefore already aware of us, waiting for us to make the first move.
METI, led by Vakoch, is now working to target star systems within 20 or 30 light-years with repeat messages as part of an effort to accumulate data in order to test the Fermi Paradox and the Zoo Hypothesis. Ideally, within a few decades, Vakoch and his team hope that they will generate a testable hypothesis with enough data and standard peer-review methods.
As for Miller, he’s not on Team Hawking, and thinks that the benefits of contact outweigh the risks. The potential to learn about advanced technology for space travel, repairing our planet’s environment, and many other applications is an obvious benefit to contact. For Neil deGrasse Tyson, the big benefit to contact is more profound: right now, our understanding of life is extremely limited, and that is because we only have our own, terrestrial sample of life to study. The notion that we have an understanding of the tremendous diversity of life is somewhat silly when you think of it in this context; our entire set of observations all share a single origin and an encoded existence that transmits heredity and mediates replication via nucleic acids.
Our current understanding of life is too much like the infamous legal definition of pornography — the classic “I know it when I see it” — which, for Tyson, lacks scientific rigor (and to clarify, he is not responsible for that icky analogy). But our explorations of the galaxy to find contact with other forms of life could give us other examples and samples, and a truer sense of what life truly is. This kind of knowledge has the potential to change everything else we think we know, most likely for the better.