Earth may be the only planet that we know of that supports life, but that doesn’t mean it’s the best one for it.
A new study, published in the scientific journal Astrobiology, has identified 24 potentially “superhabitable” planets that may have conditions more suited to host life. They could be slightly older than the Earth (4.5 billion years old), “a little larger, slightly warmer and possibly wetter.” They may also orbit stars with longer lifespans than the sun, the researchers found.
“With the next space telescopes coming up, we will get more information, so it is important to select some targets,” Washington State University scientist Dirk Schulze-Makuch said in a statement obtained by Fox News. “We have to focus on certain planets that have the most promising conditions for complex life. However, we have to be careful to not get stuck looking for a second Earth because there could be planets that might be more suitable for life than ours.”
The major criteria the researchers looked at to determine the exoplanets are as follows:
- Reside within the habitable zone — defined as the area around a star where a planet could support liquid water.
- Have cooler G stars (the sun is a G star) or K dwarf stars.
- Is up to 10% larger than Earth.
- Could have a surface temperature of approximately 5 degrees Celsius greater than Earth.
The 24 exoplanets are more than 100 light-years from Earth, but could be identified by future space telescopes, such as NASA’s James Web Space Telescope, the researchers added. A light-year, which measures distance in space, is approximately 6 trillion miles.
In July, Fox News reported that the launch of the James Webb Telescope originally scheduled for March 2021 was pushed back to Oct. 31, 2021, because of the coronavirus pandemic.
Among the 24 exoplanets, none of them meet all of the criteria to be “superhabitable,” but one of them has four of the characteristics, signaling it may indeed be more suited for life than Earth.
“It’s sometimes difficult to convey this principle of superhabitable planets because we think we have the best planet,” added Schulze-Makuch, who is also a researcher at the Technical University in Berlin. “We have a great number of complex and diverse lifeforms, and many that can survive in extreme environments. It is good to have adaptable life, but that doesn’t mean that we have the best of everything.”
More than 4,500 exoplanets have been discovered by NASA in total, approximately 50 of which were believed to potentially be habitable as of September 2018. They have the right size and the right orbit of their star to support surface water and, at least theoretically, to support life.