What all chemical & physical requirements are necessary for life


I found that website that goes into detail a bit about galactic requirements, but it doesn’t cover what percentage of galaxies or solar systems are or are not capable of supporting life. Plus it doesn’t really go into detail about the earth’s requirements with things like size, an iron core, the position of the moon, etc.

Define “life”.


Oh, specifically, definition #1 is most appropriate here.

I’d suggest a trip to the library to get a copy of Isaac Asimov’s essay Planets Have An Air About Them.

It sounds as if your prerequisites are based on life as we know it; Why is an iron core or a moon necessary? Read Bill Bryson’s A Short History of Everything if you have the opportunity; it’s a great read.

Would chemical bonds be able to exist with a star that was high in radiation?

Sure, all you need is enough distance to get the temperature right, and a thick enough atmosphere to block short wavelength photons.

With an ample iron core too. I believe you need an significant magnetic field to deflect extreme radiation, like Earth has.

A deep enough ocean will help too.

Which bonds? Some are stronger than others.

carbon-oxygen, carbon-nitrogen, carbon-hydrogen. Failing those, replace carbon with silicon.