Why Scientists Think They'll Find an Alien City Very Soon | Unveiled

Why Scientists Think They’ll Find an Alien City Very Soon

One of the main challenges when searching for alien life is that we still have very little idea as to how they will communicate. But, fortunately, searching for ET messages isn’t our only option. Researchers are increasingly saying that we should target alien planets first of all, before seeking out the aliens themselves. And, fuelled by modern technology, we could be on the brink of a major breakthrough.

This is Unveiled, and today we’re exploring the extraordinary reasons why scientists think we’ll find an alien civilization, and soon!

The search for alien life in the universe is an ever more serious topic of astronomical study. The chief organization leading the charge is SETI, or the Search for Extraterrestrial Intelligence. SETI is the leading large-scale group in America that solely searches for alien life in the universe, doing so with a variety of telescopes. However, much of SETI’s search still relies on radio telescope technology; on attempting to recognize radio signals in space as either natural phenomena or artificial, alien-made broadcasts. This, though, perhaps isn’t a surefire way to find intelligent life. There’s always the chance that an alien force wouldn’t send messages via radio, for starters… or that we would be unable to recognize a message if we actually ever received one. The best example is probably the famous “Wow!” signal. Received back in 1977, it seemingly had all the signs of being created by an intelligent species… but, more than forty-five years later, and we’re still not sure if that’s the case or not. We only heard the “Wow!” signal once and have never managed to get another sample. Was it alien life or just a natural process in space? No one knows, because radio messages remain so ambiguous to us. Might it, then, be high time for a change of strategy?

Many scientists want to now find more definitive markers of alien power, and especially visible signs. Technosigntures are exactly as they sound - characteristics or effects detectable on a planet, moon, or cosmological object that explicitly point to the presence of technology, and therefore intelligent life. As such, some argue that radio signals shouldn't be included under this classification, that they shouldn’t be considered a true technosignature, because they leave so much room for uncertainty. Examples of firmer, much less debatable technosignatures are generally large scale megastructures that are big enough to be seen from across space. Hypothetical concepts like Dyson Spheres, a massive machine to harvest energy from a star; or Shkadov Thrusters, which are giant devices that can move stars and are known as stellar engines. These would all be certain signs of a civilization.

Technosignatures have an advantage over biosignatures, too, or signature effects created by biological life, because technology can outlive biology. Studies have suggested, then, that technosignatures could be more common in the universe, and also that they should be easier to see, should last longer, and should be easier to understand than possible biological traces. This means that even were an alien group to go extinct, there’s a chance that we could still “discover” them by spotting one of their techno-structures hundreds or thousands of years later, long after their biological imprint had disappeared. If we view the universe searching for machines rather than straight up life, then the chances dramatically increase that we will find evidence that we really are “not alone”.

Published in the journal “Acta Astronautica”, a new study by lead author Jacob Haqq-Misra and an international team of scientists was written as the result of a NASA workshop, and it argues that we already have the tools to start studying technosignatures in depth… it’s just that, generally, we don’t seem to be using them. One reason for this is the cost. Funding can be difficult to obtain for studying non-radio technosignatures, perhaps because they’re sometimes so far beyond human imagination. However, Haqq-Misra and his team argue that grant funding isn’t necessarily needed, as most space missions that are already underway could be adapted to specifically look for technosignatures, at no extra cost.

That “beyond human imagination” aspect, though, is another problem. Even our brightest scientists don’t really have a solid understanding of which signatures could be artificial, and which could be natural. In both cases, we’re largely guessing as to the machines or life forms that could be making them… so there remains a big gap in our knowledge, creating a similar level of ambiguity as seen with radio waves. One solution to the current hesitancy would be for the astronomical community to come together, to catalog and understand the various types of technosignatures that we might expect an intelligent civilization to produce. If we had a library of possible signatures, then we’d have a much surer base to work from, and could apply that library to every single exoplanet we come across. But, unfortunately, no such grand project exists. There are private enterprises, like Breakthrough Listen… and there’s some interest from within SETI, although radio waves remain most studied. But, at present, we’re at something of a dead end. A valid technosignature could be our best bet to find alien life, but we’re still hedging our bets with radio and largely neglecting the search for technology.

Undeterred, however, Haqq-Misra’s study provides specific examples of the technosignatures we should be looking for. Using different observational mediums such as ultraviolet, visible, and infrared radiation, astronomers can search for a wide variety of markers like “waste heat, energy-intensive illumination, surface modifications, atmospheric pollution, stellar pollution, non-terrestrial artifacts, and megastructures”. One sign of technology, for example, could be present in a planet’s atmosphere. The paper suggests that by examining the atmospheric content for artificial molecules like sulfur hexafluoride, or by looking for expected signs of life like oxygen or methane, we could clearly identify the worlds that are the best candidates for life. Of particular interest here is nitrogen dioxide, because while it can occur naturally on Earth, human technology produces exponentially more of it through the burning of fuel. Should NO2 turn up when we look at another world, then, there could be a good chance of some similarly industrial, intelligent creatures living there.

As bizarre and seemingly straightforward as it sounds, there are also calls (within the study) for astronomers to look more pointedly for cities just as optical light. For massive city structures that could shine brightly enough on their home planet so as to be picked up by simply watching for long enough. It’s thought that aliens more advanced than us might have built what’s known as an ecumenopolis. This is a city so advanced and vast that it covers the entire surface of a planet. And the immense light that such a structure would generate should clearly shine out across the distances of space, not unlike stars do. And then, against the potential backdrop of an ecumenopolis, researchers might also try to pick out artificial satellites as the next greatest sign that life is present. There are even some proposals that the movement of satellites could double up as a method of cross-cosmological, ET communication, too.

Again, for those pushing for a greater emphasis on technosignature hunting, the beauty is that all of these examples can be searched for in the data we already have. And current and future telescopes can add in technosignature searches at no added cost, as well. According to those behind this latest study, current telescopes (or current data banks) that are already fit for purpose include the Kepler space telescope, the Transiting Exoplanet Survey Satellite (TESS), the Gaia Spacecraft, the James Webb Space Telescope, and more. With Webb, we’ve already seen the incredible detail our telescopes can now produce, with the “atmosphere composition” study of WASP-96b, an exoplanet that’s 1,100 lightyears away.

It’s perhaps surprising, then, that there hasn’t yet been a significant search made for technosignatures. More than 5,000 exoplanets have now been cataloged, but they’ve yet to be thoroughly scoured for tech signals. It’s the hope of Jacob Haqq-Misra, his team, and a growing number of other scientists that this will soon change. And there is reason to think that it will. The first ever NASA grant given specifically for the study of technosignatures was awarded in 2020, to the astronomer Adam Frank. There are calls to add machine learning processes into our study of the moons and planets that we do know about, too, to increase speed and efficiency into the future. And so, the push toward this new way of thinking is gathering pace.

Of course, all of this raises further interesting questions; could we have already spotted an alien world without realizing it? Might we have already viewed alien life, just without understanding what we were seeing? Our 5,000 confirmed planets is certainly only a small window relative to the rest of the universe, but could one of those worlds be home to… something else? Very, very possibly. And that’s why scientists think they’ll find an alien civilization, and soon.