It's popular to talk about how wonderful, beautiful and rare a treasure our planet is; I certainly say such things all the time, and many, Instagram and Pinterest photos testify to this truism. But let's be real for a minute, my fellow humans and -- we don't really have firsthand experience with an adequate sample size of to say this for sure.
In fact, a pair of scientists have been looking into the possibility that there might be a distant planet (or a couple of them or maybe 3 billion) out there more suitable to supporting life as we know it. They even describe what such a "superhabitable" planet might look like -- a super-Earth with a mass double or triple that of our planet, orbiting in the habitable zone around a K-type dwarf star several billion years older than our sun.
The basic explanation for why such a planet would make a "better Earth" is that it might have a long-lasting magnetic field, which protects the planet from the abundant radiation of space and stars, and plate tectonics activity, which keeps some of the key life-supporting elements in balance. Also, a planet with double or triple the mass of Earth would mean more surface gravity, likely forming more shallow lakes and oceans, more archipelago-like land masses and fewer deserts. More shallow waters might mean more biodiversity, as they typically do here on our planet.
In other words, a better Earth would be a little more "Water World" and a lot less "." It would also be awesome for snorkeling.
That's part of the case that René Heller of McMaster University in Ontario and John Armstrong from Weber State University in Utah plan to make at the 2015 Astrobiology Science Conference in Chicago in June, according to an advance briefing on the session (PDF).
The duo admit that they are refuting the Rare Earth Hypothesis, which basically posits that the emergence of life on Earth was a result of amazing coincidences and everything being in the right place at the right time.
"While we agree that the occurrence of another truly Earth-like planet is trivially impossible, we hold that this argument does not constrain the emergence of other inhabited planets," Heller and Armstrong write.
In other words, keep your " Prime Directive, as it could come in handy in a distant future, especially if a superhabitable planet is discovered in orbit around Alpha Centauri B, one of the nearest stars to our solar system at just four light-years away." dreams alive and always remember the
This next door neighbor, cosmically speaking, fits the requirements set by Heller and Armstrong for fostering possible super-snorkeling worlds as described above. Astronomers have already found one Earth-size planet in orbit around this star, but it is not in the habitable zone. However, there's no reason to believe that there isn't a super-Earth lurking a little farther away from Alpha Centauri B yet to be detected.
For now, until we build our firstor send out our first multi-generational ship of colonists to Alpha Centauri B, we'll just have to deal with the planet we've got, where frankly, even the and the are still pretty awesome.