The search for life in our solar system (other than here on Earth) continues. A new study out now suggest there could be 24, superhabitable earths in the exoplanet realm. 'Some planets may be better for life than Earth',
https://phys.org/news/2020-10-planets-life-earth.html
The paper cited is 'In Search for a Planet Better than Earth: Top Contenders for a Superhabitable World',
https://www.liebertpub.com/doi/10.1089/ast.2019.2161 This study suggest that earth may not be the best place for life
Some observations from me on this study.
1. Stars that can live longer than our Sun can be better for life than our Sun.
2. a superhabitable exoplanet likely needs to be larger than earth size. The report mentions a super-
earth about 1.5 earth masses as a possible model.
3. a superhabitiable earth likely will have more liquid water than our earth does today.
This study shows that habitable earths orbiting class G stars (similar to our Sun) in the Milky Way,
apparently is an idea largely abandoned now because of the more than 4300 exoplanets documented,
not confirming habitable earths around other class G stars in the Milky Way. Astrobiology using the
assumption of abiogenesis for the origin of life is looking elsewhere today. 24 possible superhabitable
exoplanets are presented in this new astrobiology study.
At the present, only Earth is definitely known to have life on it today and in the past (e.g. fossil record).