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 < email@example.com> wrote: > Why Extraterrestrial Life May Be More Unlikely Than Scientists Thought > https://www.eurekalert.org/pub_releases/2018-04/ras-pop040318.php > https://www.telegraph.co.uk/news/2018/04/05/alien-life-may- > unlikely-previously-thought-according-new-study/ > https://www.livescience.com/62248-extraterrestrial-life-phosphorus.html > > Phil Cigan > https://www.researchgate.net/scientific-contributions/205852 > 1845_Phil_Cigan > > An unrelated article is: > > The Scientific Paper Is Obsolete. Here’s what’s next. > James Somer, The Atlantic, April 5, 2018 > https://www.theatlantic.com/science/archive/2018/04/the-scie > ntific-paper-is-obsolete/556676/ > > Yours, > > > Paul H. > > ______________________________________________ > > Visit our Facebook page https://www.facebook.com/meteoritecentral and the > Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > Meteoritefirstname.lastname@example.org > https://pairlist3.pair.net/mailman/listinfo/meteorite-list >
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