[meteorite-list] Why Extraterrestrial Life May Be More Unlikely Than Scientists Thought
From: Alfredo Petrov <alfredo_at_meteoritecentral.com>
Date: Mon, 9 Apr 2018 11:54:36 +0900
Apart from possible paucity of phosphorus, there are several other reasons
why advanced life could be much rarer than previously thought. Currently
everyone is looking for planets in the "habitable zone" around stars, but
we don't know what % of planets within a habitable (ie. temperature
suitable for liquid water) zone could develop advanced life. So far we only
know of one such planet, our own. It is likely that plate tectonics is a
necessary condition, for nutrient recycling, climate control, etc. Earth
has it; Mars and Venus do not. How commonly do Earth-like planets develop
plate tectonics? We don't know.
A large moon will likely be a requirement for advanced life too, for
several geophysical reasons, and large moons seem to not be common with
Earth-like inner planets. Mars and Venus, again, don't have one. And so
on... Books have been written on this topic, years ago. I just finished one
that was written about 20 years ago, by Peter Ward and Donald Brownlee: "Rare
Earth: Why Complex Life is Uncommon in the Universe"
On 9 April 2018 at 10:19, Paul via Meteorite-list <
meteorite-list at meteoritecentral.com> wrote:
> Why Extraterrestrial Life May Be More Unlikely Than Scientists Thought
> Phil Cigan
> An unrelated article is:
> The Scientific Paper Is Obsolete. Here?s what?s next.
> James Somer, The Atlantic, April 5, 2018
> Paul H.
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Received on Sun 08 Apr 2018 10:54:36 PM PDT