Astronomers stumble upon mysterious celestial objects that could either be signs of advanced alien civilizations or simply dusty quasars. This blog post explores the intriguing debate surrounding the search for Dyson spheres and the challenges in distinguishing them from other cosmic phenomena.
Searching for Ships of the Gods
You might think that any truly advanced alien civilization would be easy to detect. A really advanced alien race would walk the cosmos like gods, making things on a star or galaxy scale.
That idea has inspired astronomers to look for the leftovers of these cosmic formations —something so huge and uncommon that it shouldn’t exist on its own. The idea that most them seem plausible to us is a giant structure surrounding each star in the society–something along the lines of a Dyson sphere, which captures all or most of the energy emitted by a sun. It might emit an odd combination of infrared or radio light — an alien fingerprint seemingly admixed with quenched intensity; a ghostly wail.
Astronomers had therefore been spending time combing the Milky Way for anything that might be a Dyson Sphere. One of the major searches, called Project Hephaistos, used such combination of Gaia data with 2MASS and WISE data in order to scrutinize five million sources. This allowed them to identify seven bizarre objects, which seemed at first glance like M-type red dwarfs but whose spectra didn’t quite fit the bill.
The Dusty Quasar Conundrum
After astronomers suggested they had detected signs of advanced aliens building huge megastructures, other scientists brought some rather more mundane news. They also suggested that the seven candidate objects could represent Hot Dust-Obscured Galaxies, or hotDOGs.
They correspond to quasars — the intensely glowing centers of faraway galaxies — blocked by such vast totals of dust that they shine generally in the infrared. Their spectra are often quite different from that of a typical star.
Now the challenge is to know when we are really seeing a hotDOG and not in turn hotDogs or an actual Dyson sphere. Here is where a new paper on arXiv comes into play. Rather than attempting to separate the two, the authors explore the probability distribution of known hotDOGs. Statistically, they concluded, a hotDOG-type quasar ‘should be about 1 in every 3,000 quasars,’ which means that if we are to search for Dyson spheres broadly, then we should also observe some dusty quasars.
The authors add that any civilization capable of constructing star-scale architectures could also potentially mask their infrared signature. We simply cannot just throw up our rigorous ideas on why aliens would build Dyson sphere out of the window.
Conclusion
The hunt for alien megastructures continues to be an interesting if still unfulfilled endeavor. The seven candidate objects that Project Hephaistos found are indeed tantalizing, but they can still be explained by normal cosmic events, such as dusty quasars. The point here is that extraordinary claims need extraordinary evidence, and we should always be open minded and on the alert for signs of ETI. The universe, likely has more surprises in store for us, and it falls to us to continue exploring with the kind of scientific endeavor motivated by curiosity.
