Planet K2-18b "best candidate for habitability"

[Stevicus]

In my view there is no need to find a "new home" because if we do as we did on earth we just destroy the next planet too. So better to find solution here on earth and fix what we done wrong so far here.

Well, it's a moot point anyway, since there's little likelihood of any humans being able to venture out that far. It would take 137,000 years to reach Alpha Centauri (how long would it take us to travel to alpha centauri [Ask An Astronomer]), and that's a mere 4 light years away. This planet is 110 light years from Earth.

As for fixing things here on Earth, I agree. I think humans have been trying to fix things. In fact, all of human history can be seen as constant attempts to fix things and make things better, although all too often, we've fixed them wrong - or created more problems in the process of "fixing." We're still trying to fix things.

 

[Subduction Zone]

I'm curious about that claim also. A red dwarf should be producing *less* UV radiation, for example, than our sun.

Given the hydrogen in the atmosphere, I doubt there is much free oxygen, which means no ozone, which means more radiation gets through the atmosphere.

On the other hand, the Earth didn't have much free oxygen for quite a while, yet bacterial life existed during that time. In fact, free oxygen is one of the markers they plan to use to say there could be life on another planet since it is made primarily by living things.

Early life in Earth was in the seas. I don't know how transparent liquid water is to UV but I would think only a few feet would be needed for protection.

Edit:

Apparently water is highly absorbent in the UV range

Transparency of Water in the Visible Range