The confirmation of the discovery of an exoplanet orbiting Proxima Centauri, the nearest star to our own, was announced recently and the accompanying bombshell was that the planet, dubbed “Proxima b,” is potentially habitable and, by extension, potentially inhabited with alien life. This, of course, does not mean that Proxima b is inhabited, but given its location in Proxima Centauri’s habitable zone, the potential for life, given what is known about living organisms in general, is there. So, presupposing that Proxima b is inhabited with alien life, what would the implications be for science and humanity?
First, it should be noted, as was pointed out by The Verge this week that just because an exoplanet has been found in the habitable zone and is potentially habitable does not mean that it is habitable or even inhabited. Proxima b’s parent star, Proxima Centauri, also presents factors making the emergence of life on the exoplanet difficult, such as being a red dwarf and having a propensity for flaring. If life on the exoplanet could somehow survive the flares, then it would have to deal with the intense radiation, because Proxima b is a mere 4.4 million miles (7.5 million km) from its parent star, which is just five per cent of the distance between the Earth and the Sun.
Seth Shostak, senior astronomer at the SETI (Search for Extraterrestrial Intelligence) Institute, told LiveScience that the question of whether or not alien life is present on Proxima b is “not easy” to answer. “So far, no one has seen it — they’ve measured a very slight wobble, about the speed at which you walk… that tells you there’s a planet there, and tells you something about its mass, but it doesn’t tell you anything about the conditions on the planet.”
That’s because the exoplanet was discovered using the radial velocity method, which detects a gravitational wobble in the planet star that is usually a tell-tale that a planet is in attendance. Thus far, Proxima b has eluded sighting via the transit method, which is when astronomers catch sight of a planet passing in front of its parent star. Doing so would be helpful in determining whether or not the planet was amenable to living organisms due to astronomers being able to get a clearer picture of what makes up the exoplanet’s atmosphere. Shostak told LiveScience that just a small “pixel dot” image would be all that was needed to get the information indicating whether or not “something biological was going on.”
But if alien life were to be found on Proxima b, how would that knowledge affect humanity? From a scientific perspective, it would strongly suggest that life there and on Earth developed independently, given that the planets are 4.2 light years apart (unless, of course, the Panspermia Theory, that life throughout the cosmos was seeded and has common ancestry, holds true).
David Kipping, an astronomer at Columbia University, said to The Verge, “But it would be nearly impossible to link Earth life to any life we find on Proxima b. It would mean that life starts completely independently in at least two examples.” He added, “And if it happens in two places, it probably happens everywhere. It would kind of close the loop in how common life is in the Universe.”
Shostak believes there is a philosophical impact that finding alien life would have on humanity, preceded by the realization that Earth was not unique in fostering life. “I think that from the philosophical point of view — set aside all the biology and other scientific implications — the philosophical import would be very substantial: sort of like being in Europe in 1492 and learning of the existence of a New World,” he said.
In short, finding alien life on Proxima b would have a profound impact on just about every aspect of human existence. Still, proving that there is life on the nearest exoplanet will be difficult. Conclusive proof could be decades to centuries in the future.
According to Matt Williams at Universe Today, even the fastest spacecraft in operation today would take tens of thousands of years to get to the triple star system of Alpha Centauri (of which Proxima Centauri is a member). Voyager 1, which is just outside the heliosphere of the Solar System, would take 76,000 years. The experimental EM Drive being developed at NASA, if it works as projected, would get a spaceship to the nearest star in roughly 13,000 years.
The fastest way to get to Proxima Centauri might well be the laser-driven sails that would propel the small spacecraft of the Starshot Project, the much-touted endeavor undertaken by Russian billionaire Yuri Milner and astrophysicist Stephen Hawking, on its way to the nearest stars. They are, however, still under development. But if they’re ever operational, the small craft are expected to make the trip in two decades.
Of course, with all the attention the stellar area will undoubtedly get in the coming years following the discovery of Proxima b, confirming alien life might come from some other method or one yet to be developed or invented. Or perhaps, after six decades of fruitless searching, SETI might detect a first contact signal from nearby Proxima b.