Origin and Development of Earth's Atmosphere

[M.T.]

Hello, I'm a newbie so please tell me if I'm doing anything wrong :)

I am working on a portfolio for school and I have chosen the topic "Air". As I was all set and ready to start, I realized that I didn't know the first thing about air. By now I know that what we call "air" is in fact the atmosphere surrounding the earth... and that's as far as wikipedia could help me. But the amount of my remaining questions scrapes infinity, so I would be very thankful if somebody could answer even some of them:
When has this athmosphere started to exist? Was there a time when the Earth existed without an atmosphere around it? Do these gases also exist somewhere outside Earth's atmosphere? If that's the case, could it be that those gases were "pulled down" to earth? Or is it that rather than being pulled down to it, the Earth "emitted" those gases? If so, does the Earth still emit gases (maybe even "new" gases)?
Has the atmosphere changed and is it going to change over the years? If yes, did organisms also change according to the atmosphere? Or did the atmosphere change according to the organisms?
Do other planets have an atmosphere? And, I hardly dare to ask, what about stars, meteors and the like?
Could we, willingly, change or influence the atmosphere and is this bascially what everbody calls global warming?

Thank you in advance :)
(Sorry, if my English seems a bit weird, it's not my mother tongue)

 

[JaredJames]

Well the wikipedia page has everything you need. So I'm not sure why you say it couldn't help you?

I just skimmed through it and it's perfect. It answers all of the questions you've put above.

http://en.wikipedia.org/wiki/Atmosphere_of_Earth

It even has a section outlining the 'history' of the atmosphere.

Just a nice long bit of reading for you, no one here will summarise it down to save you the time.

 

[Studiot]

Hello MT and welcome to PF.

These are all very good questions for a school boy or girl.

I must tell you that we do not have definite answers for all of them.

First the question of did Eath always have an atmosphere?
Well that depends upon which theory you believe about how Earth was formed. But probably not.

Was the atmosphere always as it is is now?

Again there are several theories, but again probably not.
Modern theories have the early atmosphere with little or no oxygen, just nitrogen, carbon dioxide and perhaps some water vapour plus various volcanic gasses and dusts.

Did life have any part to play?

Modern theories suggest that about 3000 million years ago very primitive organisms called stomatolites started using carbon dioxide (which was at a much higher level than today)and water to form cellular material and releasing oxygen.

I think these are the key points. Others here with greater knowledge than mine my chip in with more detail.

go well

 

[Studiot]

I wonder how MT is getting on with his (her) project.

I do hope we haven't frightened off a budding scientist.

 

[M.T.]

No, I am in fact more hyped up about the topic than ever - I just happened to have no internet for the past few days. Thank you for your answers and your kind concern :)
So, please correct me if I'm wrong, but does that mean that oxygen is a product of early living creatures and that our higher forms of life are therefore dependent on them? But, yes that does make sense - as with trees and humans! Okay, I think I just had a light-bulb moment.
So it was like that: the Earth started to exist and it may or may not be that the atmosphere existed at this point. As soon as the atmosphere did exist, we believe that it was mostly filled with gases other than oxygen and among those were carbon dioxide and nitrogen. The stomatolites made their appearance, pumped oxygen into Earth's atmosphere and more complicated forms of life developped. Did I get that right?
So it seems that life came further with oxygen-breathing individuals than with carbon-dioxide breathing individuals - does that mean anything? And, seeing it as one "group" grew out of another, could it be that we also emit some kind of gas that new and more sophisticated life forms could be dependent on or do my thoughts wander off to Science Fiction now?
And here's something I stumbled across when I was searching the internet: http://news.sciencemag.org/sciencenow/2010/04/scienceshot-animals-that-live-wi.html
1. I have to wonder: is this real or just faked? and 2. If it IS real, could this be the bridge between the oxygen-emitting and the oxygen-breathing beings?

 

[Studiot]

I haven't forgoten that it is your project. So I assume you can do some of the legwork, especially if pointed in the right direction.

I recommend the Oxford University Press book by David Beerling

The Emerald Planet (how plants changed Earth's history).

It is not certain how Earth originally formed, but it is pretty certain that the original coalescing ball of material was pretty hot. So hot that it could not be called a solid with an atmosphere. It was part solid, part liquid and part gas. But certainly too hot for any water to be liquid.

As it cooled from whatever event brought it together the lighter materials came to the outside and the heavier materials formed the core. The lighter materials were likely methane, ammonia, water etc ie compounds of the lighter elements.

This was all about 4 thousand million years ago.

Roll on a thousand million years and the Earth has stabilised - cooled and separated to solid planet and gaseous atmosphere. The planet is now cool enough for water to exist as a liquid, form clouds and rain. The rain leads eventually to the first oceans.

Enter primitive life (stromatolites still living in the Australian reefs) and the journey to the Emerald Planet begins.

 

[Xnn]

My impression is the timeline outlined in Wikipedia is about all we know from a scientific point of view:

http://en.wikipedia.org/wiki/History_of_the_EarthNotice that there was a time that Earth had no atmosphere; immediately after the big impact.

 

[Simfish]

I'll list some sources:

http://www3.geosc.psu.edu/~jfk4/PersonalPage/PDFs.htm
http://faculty.washington.edu/dcatling/publications.html
Also, see Brownlee and Ward's "Rare Earth" and "Life and Death of Planet Earth"

 

[M.T.]

Thank you -all of you! I'm going to submit my portfolio tomorrow and because of your help, I'm now sure that it wil be a success. I'm really happy that I joined this forum and I bet that I'll never regret it :D