Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: acecharly on 13/06/2012 22:09:18

Title: Could basic life have formed in the suns accretion disk?
Post by: acecharly on 13/06/2012 22:09:18
Is it possible for life to have been formed in the suns accretion disk in the sea of chemicals and elements orbiting the sun which eventually rained down on all the planets in our solar system?

Any thoughts

Cheers Ace
Title: Re: Could basic life have formed in the suns accretion disk?
Post by: CliffordK on 14/06/2012 03:56:16
It is quite possible that many of the primordial compounds required for life to form including carbon and nitrogen compounds and amino acids formed prior to accretion of Earth.

Let's assume that Abiogenesis, or the beginning of life, requires liquid water. 

The triple point of water is at 0.01C, and 0.006 atm, and the boiling point is 100C at 1 atm.  Any lower pressure, or higher temperatures, and water can not exist in liquid form on the surface of an object.  It also has a fairly high vapor pressure, so it would tend to evaporate in a low pressure environment without an atmosphere.  Still, it is possible for it to exist in pockets encapsulated in another matrix.

Anyway, you would have to define an environment in which liquid water would exist, and would be relatively stable.

So, my vote is that life would not be possible until the accretion of objects at least the size of our moon, perhaps even significantly larger, if near the place where Earth is in the solar system.

The energy released from the impacts of large celestial bodies could potentially snuff out any early life on small planetoids.
Title: Re: Could basic life have formed in the suns accretion disk?
Post by: chris on 14/06/2012 08:20:33
Jeff Bada from UCSD contributed a very interesting interview to the Naked Scientists this week in which he discussed possible origins for the biological building blocks of life, based on his findings from reanalysis of Stanley Miller's famous 1950s experiments.

The intriguing thing Jeff points out is that the molecules he has found are a close match for what also turns up in some species of meteorites; pressed on this, he speculates that conditions similar to those created in Miller's apparatus could also have existed in the early solar nebula; so Earth might not have been the place where the building blocks of life were made; they could have been synthesised elsewhere but then landed here, conveniently.