Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: neilep on 13/09/2016 13:08:51

Title: Where does The Water On Comets Come From ?
Post by: neilep on 13/09/2016 13:08:51

Dearest Science Peeps of extraordinary knowledge and klevur knowing stuff,

As a sheepy I imbibe water every day, it's my all time fave drink, but sometimes i need to dilute it with more water !!





Its often been said that Earth obtained its water from Comets, so:

Where did the comets get their water from ?

do ewe know ?

I don't !!...and i'd like to know  !!


Thanks

Hugs and shmishes


mwah mwah !!




Attached is a piccy of a comet, not to be confused with a cabbage ok ?   they both  begin with C and are round easily confused !

Title: Re: Where does The Water On Comets Come From ?
Post by: VanVinci on 14/09/2016 22:42:23

Most comets were formed in the Oort Cloud
I CANT POST LINKS___en.wikipedia.org/wiki/Oort_cloud#/media/File:PIA17046_-_Voyager_1_Goes_Interstellar.jpg

The Oort Cloud lies at a distance of between 1000 100,000 times the distance the Sun is from earth.
The region is filled with water vapor and dust particles. Thus, this is what Comets are made of.

Before the earth cooled enough for a crust to form most of the water accumulating in the disk would become rapidly vaporized and blown out into space.

Only after a crust formed was there a chance for the influx of water from sources such as comets to begin to collect in significant amounts.

Recently, a Radio Telescope Array imaged  a Protoplanetary Disk
I CANT POST LINKS___en.wikipedia.org/wiki/Protoplanetary_disk

It's like a snapshot looking back at our own Solar System 4.5 Billion Years Ago.

The Gravity of the central star vs the Centrifugal Force, wanting to sling matter outward, causes the matter in an Accretion Disk to 'Stratify' from heaviest to lightest components and you move outward.

Title: Re: Where does The Water On Comets Come From ?
Post by: evan_au on 14/09/2016 23:04:20

Quote from: neilep

Where did the comets get their water from ?

Hydrogen is the most common element in the known universe (excluding unknowns like Dark Matter). It originated in the Big Bang.

Medium-sized stars will burn much of their hydrogen to elements like Carbon, Oxygen or Nitrogen (larger stars produce a lot of silicon, and very large stars produce iron & nickel). When these stars explode in a supernova, they blast much of this matter into space.

So it is not surprising that the protoplanetary disk and Oort cloud from which the Solar System condensed had a lot of compounds of these chemicals.

The cold Oort cloud included a lot of compounds with low boiling points like oxides of Hydrogen (water), oxides of Carbon (CO, CO₂), hydrides of Carbon and Nitrogen (NH₃ ammonia, CH₄ methane and larger hydrocarbons), cyanide (HCN), amino acids as well as O₂, N₂, C_n.

Planets forming in hotter regions contained compounds with higher boiling points, like silicates (SiO_2n) and iron.