We are looking for aliens in the wrong places - scientist
“The Earth just scrapes the inner edge of the solar system’s habitable zone — the area in which temperatures allow Earth-like planets to have a liquid surface water,” René Heller of McMaster University, Ontario, Canada said. “So from this perspective, Earth is only marginally habitable. That led us to ask: could there be more hospitable environments for life on terrestrial planets?”
As the scientist writes, living organisms, in the sense we know them, were lucky to survive and evolve on Earth between the asteroid and comet bombardments, intense volcanic activity, frigid ice ages and often poisonous atmospheres.
So Heller and her colleague John Armstrong of Weber State University suggest looking for superhabitable planets instead of a “second-Earths”. Such planets are supposed to have particular features such as a more efficient global “thermostat” that would avoid destructive ice ages, shallower oceans and a global magnetic field to protect life from ionizing solar wind particles.
According to Discovery News, the scientists highlight the nearby star Alpha Centauri B as an ideal candidate that could support a superhabitable world. Slightly smaller than our sun, Alpha Centauri B would be able to incubate hypothetical lifeforms on a superhabitable world for much longer owing to its longer lifespan. "You want to have a host star that can keep a planet in the habitable zone for 7 to 10 billion years," which would allow enough time for life to evolve and ecosystems to flourish, Heller said.
“We propose a shift in focus,” said Heller. “We want to prioritize future searches for inhabited planets. We’re saying ‘Don’t just focus on the most Earth-like planets if you really want to find life.’”
The researchers believe our hunt for extraterrestrial life is too set in its ways and blinkered toward worlds that we consider to be habitable because they resemble Earth. It’s a grand observational bias that may ultimately mean that while looking for second-Earths, we overlook far more habitable planets.
There is no question that the search for extraterrestrial life needs “out of the box” thinking and needs various approaches.