From Scientific American - 地球人去其他星球有別的選擇？Humans are worse than scum.
Faraway Planets May Be Far Better for
Life
Astronomers have come up with a shopping list of what a
planet needs to support life, perhaps even better than our Earth does, making
them "superhabitable."
Michael Moyer reports
Earth is the only place where we
know for sure that life exists. We have liquid water and a strong magnetic field磁場 that shields out harmful
cosmic
radiation宇宙輻射.
But what if Earth isn’t the most habitable 適合居住type of planet? Researchers say they’ve listed the qualities that would make a planet extra-friendly to life, or “superhabitable超級宜居.” Their paper is in the journal Astrobiology.
But what if Earth isn’t the most habitable 適合居住type of planet? Researchers say they’ve listed the qualities that would make a planet extra-friendly to life, or “superhabitable超級宜居.” Their paper is in the journal Astrobiology.
A “superhabitable” planet should be two or three times the size of Earth. The extra surface area provides more room for species to spread out散布 and evolve演化. And the stronger gravity of a giant-Earth巨大地球 would flatten 夷平the surface, allowing for more lakes and archipelagos群島—crucibles of life廣納各種生命的大熔爐 here.
Our “superhabitable” planet should also be well-aged老的剛剛好(有一定的年紀，但是又不會太老). The sun and earth are about five billion years old—middle aged, cosmically speaking. But some stars that are slightly smaller and dimmer較為微弱 than our sun are more than 10 billion years old. That’s a lot of extra time for life to take hold主控 and evolve.
Astronomers estimate that our Milky Way galaxy銀河系 is home to around 100 billion planets. Compared with planets yet to be found, Earth could barely be making a living簡直不能比/幾乎快要混不下去.
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