Earth does not necessarily have to be the “best” planet in the entire universe, however privileged we may feel.
Now, a team of scientists led by astronomer Dirk Schulze-Makuch of Washington State University (USA) has identified two dozen planets outside our solar system that have characteristics of potential “super-habitable” planets, this means that they would be even more conducive to life than our own planet. This group of “super-habitable” planets would include planets older, larger, slightly warmer, and possibly more humid than Earth. This discovery clearly indicates to us that life could easily thrive on planets revolving around stars that change more gradually with a life expectancy longer than our Sun.
On the hunt and capture of habitable planets
The researchers identified superhabitability criteria and looked for potential candidates among the 4,500 known exoplanets. They selected stellar systems with probable terrestrial planets orbiting within the liquid water habitable zone of the host star from Kepler’s Object of Interest Exoplanet Archive of transiting exoplanets.
“While the Sun is the center of our solar system, it has a relatively short lifespan of less than 10 billion years,” the authors recalled. “Since almost 4 billion years passed before any complex life appeared on Earth, many stars similar to our Sun, called G-type stars, could run out of fuel before complex life develops.”
While no planet of the newly discovered meets all the criteria for ‘super habitability’, they all score higher than Earth overall. And, specifically, one of them would have four of the most critical or important characteristics, which makes it, possibly, much more comfortable for life than our own planet of origin.
Despite the fact that all the worlds are more than 100 light-years apart , too far away for us to visit, scientists explain that the discovery may aid in the search for life in other parts of the universe.
Are they really habitable?
The fact that these planets are exposed to meet the conditions for ‘superhabitability’ does not mean that they are really habitable (it is not about arriving and starting farming) since our telescopes cannot yet see their atmospheres; for that we will have to wait a few years. But it does represent a rocky planet that is in the correct orbital region around its star, where the temperature is moderate enough that liquid water exists on its surface without freezing or evaporating.
In the same way, size and mass must be taken into account. Part of the fact that the Earth is a habitable place is that it is large enough to be geologically active, giving us a protective magnetic field and enough gravity to retain the atmosphere. If the Earth were even larger (10% more, for example), it would have more surface area to live on, and if it were more massive, its interior would retain more heat, it would remain active longer and, therefore, the atmosphere would still remain. more.
“The study could help focus future observing efforts, such as those of NASA’s James Web space telescope, LUVIOR space observatory and the European Space Agency’s PLATO space telescope. With the next space telescopes, we will get more information, so it is important to select a few targets. We have to focus on certain planets that have the most favorable conditions for complex life. However, we must be careful not to get stuck looking for a second Earth because there could be planets that could be more suitable for life than ours, “clarifies Schulze-Makuch.
Referencia: Dirk Schulze-Makuch et al, In Search for a Planet Better than Earth: Top Contenders for a Superhabitable World, Astrobiology (2020). DOI: 10.1089/ast.2019.2161
