According to an Inverse report, a team of astronomers led by Leiden University researcher Hongying Chen is actively searching the skies for advanced alien life forms.
They’re looking for infrared signals that could be the exhaust emissions of hypothetical Dyson spheres, which are massive megastructures that harness the energy of the surrounding universe. Their new paper focuses on two distant galaxies whose infrared emissions have previously eluded simple explanation.
In search of super-intelligent alien life
Is there any life out there? According to the Fermi Paradox, it is extremely likely, given that there are billions of stars in the Milky Way alone, many of which have planets orbiting in habitable zones. Despite this, we have found no evidence of intelligent alien life. New discoveries, such as the recent discovery that Mars has always been too small to retain surface water, are constantly changing our understanding of the likelihood of discovering intelligent life in the far reaches of space.
Chen and his colleagues believe that if there is life out there, the most likely way to find it is to look for the traces of the most advanced civilizations. They are specifically looking for Kardashev Type III civilization (K3) lifeforms. The Kardashev scale was proposed in 1964 by Soviet astronomer Nikolai Kardashev as a way to measure the level of technological advancement of a hypothetical civilization based on the amount of energy it can harness from the surrounding universe.
As the most advanced type of alien civilization, K3 lifeforms are at the top of the scale. According to the scale, they would be able to harness the energy of black holes, stars, and quasars using technologies similar to the hypothetical Dyson sphere — a massive structure that could surround a celestial object such as a star without collapsing. It’s worth noting that humans aren’t even considered Type 1 yet, as that would necessitate us efficiently harnessing the power of the Sun. Chen and his colleagues scanned a portion of the Northern Sky for galaxies that could be home to K3 alien lifeforms. So far, two galaxies have stood out among the 21 they have studied. They describe their findings in a paper published in the Royal Astronomical Society’s Monthly Notices.
Narrowing down an infinitely broad investigation
The researchers behind the new study believe they can detect a Type III civilization by looking for mid-infrared emissions in the sky. These, they believe, could be telltale signs of advanced alien races emitting Dyson Spheres — Chen’s team writes in their paper that K3 civilizations are likely to “generate strong excess emission in the mid-infrared (MIR) that is associated with the waste heat they generate.” The researchers examined the emissions of 21 galaxies with high mid-infrared emissions and discovered that four of them had mid-infrared emissions that were multiplied by a factor of ten. One of these was an active galactic nucleus, and the other was a star-forming galaxy, indicating that they are natural sources of mid-infrared emissions. The other two galaxies, known as ILT J134649.72+542621.7 and ILT J145757.90+565323.8, however, are not so easily explained, and the researchers say they “require further investigation.”
The researchers’ next goal is to pinpoint the precise source of the infrared emissions. “We can look at their emissions in other wavelengths like X-ray and optical to see if their spectral energy distribution is active galactic nuclei-like or star-forming-galaxy-like,” Chen explained in an interview with Inverse. “We can also conduct high-resolution radiological observations on them to examine their morphology.” They also intend to scan other parts of the sky for possible signs of hyper-advanced alien life.