Scientists are currently exploring the "habitable zones" of nearby stars to detect signs of extraterrestrial life, which refers to the area around a star where liquid water could exist.
However, as Science Alert reported, a recent research paper suggests that a more detailed and cautious method is required, which should focus on the potential for computation instead of life.
New Search Criteria for Extraterrestrial Life Based on 'Computational Zones', Astronomers Proposed
Brief Description of Habitable Zones
Habitable zones are those regions from a star at which liquid water could potentially exist on the surface of orbiting planets, according to NASA. The concept of habitable zones, also referred to as the Goldilocks' zones, suggests that these areas could be optimal for the development of life.
When searching for habitable exoplanets, scientists focus on exoplanets that are similar to Earth, although the definition of "similar" can be subjective. Most of the Earth-sized exoplanets discovered so far are in orbit around red-dwarf stars, while Earth-sized planets in wide orbits around Sun-like stars are harder to detect.
The potential for life-bearing planets in the habitable zones is wider for hotter stars, and smaller, dimmer red dwarfs have much tighter habitable zones, which are exposed to high levels of X-ray and ultraviolet (UV) radiation.
The exoplanets in the narrow habitable zone around a red dwarf star are very close to the star and receive extreme levels of X-ray and UV radiation, which can be hundreds of thousands of times more intense than what Earth receives from the Sun. Therefore, the search for habitable exoplanets requires taking into account the type of star that the planet orbits.
It's Time To Look for Computational Zones
The new research, titled "Rebuilding the Habitable Zone from the Bottom Up with Computational Zones" available on the preprint server arXiv, suggests that one way to define life is through a set of computations that act on information. Researchers argue that information stored in DNA can be computed to know how its environment allows life to under natural selection.
Since scientists have been looking for signs of extraterrestrial life in the earthly context, specifically those who live in habitable zones, scientists of the study think that life could use other solvents and that they might even be buried in underground icy outer moons or they might not even require a star.
According to Universe Today, the researchers want to rebuild the concept of the habitable zone using the concept of computation to have better chances of finding extraterrestrial life where there is the easiest access to computation. They said that these computational zones require three characteristics.
Firstly, it must have a rich set of chemistry as this signals the capacity for computation. Secondly, there must be a raw form of energy, such as sunlight or hydrothermal vents. Lastly, it requires something where the computation may take place.
Computational zones allow scientists to develop search strategies for concepts of extraterrestrial life extending beyond habitable zones. The authors emphasize that the search for life in the universe in a scientific way is just beginning and it is important to keep an open mind.
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