Rethinking our planetary water origins.

Discussions ranging from space technology, near-earth and solar system missions, to efforts to understand the large-scale structure of the cosmos.

Rethinking our planetary water origins.

Postby Event Horizon on May 11th, 2018, 1:31 pm 

For some time it has been generally accepted that most of our water came in comets during a time in the early stages of Earths formation. However, recent analysis has shown that comet-water contains elevated levels of heavy water called Deuterium. They don't match.
A good amount of water is unaccounted for.
I was thinking, what if we also collected water that Mars evidently lost. It's a lot of water to loose and the solar wind would push it towards our orbit I would have thought.
What's more, what if life originated there and came here? Dormant in ice crystals perhaps..Anyway.

Nobody ever asks where did Mars' water go, they just agree its gone.
I think it would be interesting to find a way to deduce how much of it ended up here.
We started with high octane comet water perhaps with its deuterium 4X our levels, but something seems to have watered it down, so to speak. If not Mars, where did all the rest of the water come from?
User avatar
Event Horizon
Member
 
Posts: 299
Joined: 05 Mar 2018
Location: England somewhere.


Re: Rethinking our planetary water origins.

Postby doogles on May 11th, 2018, 4:47 pm 

I've missed the point somewhere about why there is a theory that all the water on our planet has to have an extra-terrestrial origin at all. I would be pleased if someone could enlighten me.

I've been too lazy to research it myself because of the time I'm spending on other interests.

My disposition is such that I tend to creative hypothetical working theories on anything and everything even before I do any research on the matter.

My simplistic, totally un-researched one on the elements, is that after the 'big bang', there were only precursors of electrons, protons and neutrons everywhere. As 'things' were cooling down and changing, millions of micro-environments appeared that were suitable for electrons or protons or neutrons to form from these precursors.

And then with further cooling and more microenvironments, these electrons, protons and neutrons began to coalesce randomly to form the whole range of elements as we know them. When Bohr's original classification appeared, it suggested a complete range of possibilities, including the combination of elements into molecules, depending on what micro-environments and elements happened to be in abundance at any place at any time.

Why not H and O in the primordial mass that was the precursor of planet Earth?
User avatar
doogles
Member
 
Posts: 991
Joined: 11 Apr 2009
Location: BRISBANE


Re: Rethinking our planetary water origins.

Postby zetreque on May 11th, 2018, 7:05 pm 

Event Horizon » Fri May 11, 2018 10:31 am wrote: and the solar wind would push it towards our orbit I would have thought.


Why would you have thought this?
User avatar
zetreque
Forum Moderator
 
Posts: 3640
Joined: 30 Dec 2007
Location: Paradise being lost to humanity
Blog: View Blog (3)


Re: Rethinking our planetary water origins.

Postby Event Horizon on May 11th, 2018, 8:10 pm 

Doogles. The early Earth was too hot for any liquid water to exist on the surface. We apparently gathered our water subsequent to cooling. It was long thought that comets hitting us during the "Heavy Bombardment" phase. Only it seems comet water is chemically different to ours meaning a lot came from somewhere else.

Z~ The Sun emits a constant stream of ions and other material that radiates out past the limits of the Solar system. It's called the "Solar wind" and would help push materiel from an inner orbit to an outer one. As far as Mars is concerned, we are the next planet out. We will have past through at least some of Mars' lost water in our orbits I think.
User avatar
Event Horizon
Member
 
Posts: 299
Joined: 05 Mar 2018
Location: England somewhere.


Re: Rethinking our planetary water origins.

Postby zetreque on May 11th, 2018, 8:19 pm 

Event Horizon » Fri May 11, 2018 5:10 pm wrote:As far as Mars is concerned, we are the next planet out. We will have past through at least some of Mars' lost water in our orbits I think.


In order:

Sun
Mercury
Venus
Earth
Mars
Asteroid belt
Jupiter
So on...
User avatar
zetreque
Forum Moderator
 
Posts: 3640
Joined: 30 Dec 2007
Location: Paradise being lost to humanity
Blog: View Blog (3)


Re: Rethinking our planetary water origins.

Postby Event Horizon on May 11th, 2018, 8:43 pm 

Darn. Misremembered. Thankyou Z~.

Even so, does it not seem reasonable to suspect that with Mars loosing <all> its water, and Earth mysteriously gaining a lot of water there may be a connection? I guess we won't know unless we find a sample of water on Mars we can test. It could have a yet different composition to us and comets which would be interesting too.
User avatar
Event Horizon
Member
 
Posts: 299
Joined: 05 Mar 2018
Location: England somewhere.


Re: Rethinking our planetary water origins.

Postby zetreque on May 11th, 2018, 8:49 pm 

wikipedia says that Mars has a high ratio of deuterium as compared to Earth. But all that says is it could be higher due to the evaporation of water.
https://en.wikipedia.org/wiki/Water_on_Mars

This all makes me think of the star trek episode
https://en.wikipedia.org/wiki/Thirty_Da ... k:_Voyager)
User avatar
zetreque
Forum Moderator
 
Posts: 3640
Joined: 30 Dec 2007
Location: Paradise being lost to humanity
Blog: View Blog (3)


Re: Rethinking our planetary water origins.

Postby Event Horizon on May 11th, 2018, 9:19 pm 

Very interesting Z~. It's hard to imagine a planet loosing its water in just 5 years. When I look at images of Mars, I hope I might deduce where glaciers might have receded or other evidence of a timeline, but mainly I think it's a long past source of a lot of water in our spatial vicinity.
I didn't know that water from Mars had been tested. Does evaporation concentrate Deuterium? If the value of the deuterium was diluted to approximate ours, how much water would it account for? It could tell us the proportion of Martian water that was derived by comet impact, and whether it was comparable to ours at all.
But if not Mars, then where could our post bombardment water have come from?
User avatar
Event Horizon
Member
 
Posts: 299
Joined: 05 Mar 2018
Location: England somewhere.


Re: Rethinking our planetary water origins.

Postby doogles on May 12th, 2018, 5:12 am 

Event Horizon » Sat May 12, 2018 10:10 am wrote:Doogles. The early Earth was too hot for any liquid water to exist on the surface. We apparently gathered our water subsequent to cooling. It was long thought that comets hitting us during the "Heavy Bombardment" phase. Only it seems comet water is chemically different to ours meaning a lot came from somewhere else.

Z~ The Sun emits a constant stream of ions and other material that radiates out past the limits of the Solar system. It's called the "Solar wind" and would help push materiel from an inner orbit to an outer one. As far as Mars is concerned, we are the next planet out. We will have past through at least some of Mars' lost water in our orbits I think.


I just have a feeling that the rest of the cooling universe would have had the same problems as our planet was concerned with respect to water formation because of high temperatures, and I've been wondering whether hydroxides were in abundance in other forms until the temperatures (my micre-environments above) were right for a massive combination with H atoms.

I found this recent article in a popular science magazine on the web but was unable to locate a hard research basis to back it up --
https://www.irishtimes.com/news/science ... -1.2908873 --
"Some 70 per cent of the surface of the Earth is covered by water, but where all this water came from is the subject of lively debate.

The most popular hypothesis has been that water was carried to the early Earth by icy asteroids and comets.

A rival hypothesis is that water was present on Earth right from the start. This second hypothesis received a great fillip recently with the amazing discovery of compelling evidence for a water reservoir three times the volume of all the oceans deep beneath the Earth’s surface. This discovery supports the idea that the Earth had water from the start, and the oceans were formed when water “oozed out” of the interior of the young Earth."


Can you comment on this Event Horizon? It's just that the rival hypothesis makes more sense to me.
User avatar
doogles
Member
 
Posts: 991
Joined: 11 Apr 2009
Location: BRISBANE


Re: Rethinking our planetary water origins.

Postby Event Horizon on May 12th, 2018, 3:43 pm 

Hi Doogles. It is probable that some water was trapped beneath the surface of the planet much as it is today. But it's unlikely to have escaped as water, more probably it exploded out as superheated steam to become a component of our proto-atmosphere or simply lost.
We simply wouldn't have had such a massive underground reservoir as 3 times the volume of water at the surface. The Earth would have to be considerably larger than it is to accommodate such vast amounts of water.
To my knowledge there is no evidence for this. No ocean-sized voids have ever been found underground, and the structure of the Earth is not able to support such a void without collapsing with devastating global upheaval.

The early Earth was far hotter than Mercury is now, and I wouldn't expect to find unbound water on Mercury either, comets or reservoirs included.

The consensus is that comets and meteors brought us water from afar, but it only accounts for a proportion of our water. Scientists are still trying to figure out where the rest came from, but there is no consensus regarding this as far as I know.
User avatar
Event Horizon
Member
 
Posts: 299
Joined: 05 Mar 2018
Location: England somewhere.


Re: Rethinking our planetary water origins.

Postby doogles on May 12th, 2018, 6:02 pm 

Thanks for the responses EH. It may be a personal thing with me but something does not seem right or logical about the consensus guess on this subject of our oceans of water being derived from collisions of asteroids and the likes with our planet.

I call it a guess, because I haven't seen any real scientific evidence for how H2O formed there yet.

My imagination is that similar collisions by asteroids and dust must have occurred with all the other planets and with the moon, but none of them retained the amounts of water that we have retained. And if we had the conditions to retain the water, could we not have the conditions to form the water?

I asked two questions that no one has attempted to answer. If 'heat' is the hypothetical argument for planet Earth not being able to retain formed water molecules during its cooling stage, would that problem not be pervasive throughout the rest of the cooling universe where all of these asteroids and comets are forming?

I also asked about the possibility of OH radicles being present and bound to other elements in multiple forms until conditions became right for them to preferentially combined with H. In the absence of an answer, I did a quick search.

This is a 2016 article that suggests this type of possibility and to my mind it makes more sense to my imagination than the consensus one. I'm talking about a similar process being necessary in the other hot areas where the asteroids and things had to produce H2O anyhow -- https://www.nature.com/articles/nature18018 --
"We show that the mineral goethite, FeOOH, which exists ubiquitously as ‘rust’ and is concentrated in bog iron ore, decomposes under the deep lower-mantle conditions to form FeO2 and release H2."

This is a 2018 article. I'm not sure of its implication in this interesting debate but it does suggest the latent potential for Fe compounds (at least; there could be scores of others) to store H2O in one form or another in hot, high pressure conditions -- https://agupubs.onlinelibrary.wiley.com ... 17GL075720 - "A recently reported pyrite‐structured FeO2 was identified in the Fe‐H2O system at pressures greater than ~78 GPa after laser heating. The phase observed in this study has a unit cell volume 8%–11% larger than that of FeO2, produced in the Fe‐O binary system reported previously, suggesting that hydrogen might be retained in a FeO2Hx crystal structure."

These are just the first couple of references I encountered and I feel sure that anyone in the business could locate many more.

I'll leave it at that and go against the current consensus, unless someone comes up with another more plausible angle.

If anyone does respond, it would be helpful if you provided evidence of how the water formed in the remote, at one time hot, asteroid belts, that could have been different from these last couple of suggestions.
User avatar
doogles
Member
 
Posts: 991
Joined: 11 Apr 2009
Location: BRISBANE


Re: Rethinking our planetary water origins.

Postby Event Horizon on May 12th, 2018, 11:22 pm 

I should maybe point out a couple of things Doogles.

The Earth is getting on for 4bn years old or so. The Universe is around 13.75bn years old. That gives a very long time during which water ice could exist before the Earth was even born.

Next, Hydrogen is the most prevalent element in the universe. Oxygen is third most common. It's of no surprise that a lot of water ice formed as a result. Here is a breakdown of the prevalence of elements in the cosmos..
http://periodictable.com/Properties/A/U ... dance.html

The amount of Deuterium and to an extent Tritium occurring in water is in different concentrations depending on where it came from. Our heavy water is 4x less prevalent than it should be if comets accounted for all our water. But it seems to have been diluted by a lot of water where the heavy water got left behind by evaporation as happened on Mars.
That means remaining water on Mars would be high in deuterium, which it is, and the water escaping Mars would be low in Deuterium with the potential to dilute our Deuterium levels 4x lower than Comet water which is what we see.
https://www.britannica.com/science/heavy-water
I suspect we collected a lot of lost Martian water that it shed, but I don't know the mechanism.

It will be fun to see who of us gets closer to the truth.

Best wishes EH.

*Edit* If Mars shed enough water quickly enough, it could well have produced a comet-like tail. That would have been an amazing sight to see I think.
User avatar
Event Horizon
Member
 
Posts: 299
Joined: 05 Mar 2018
Location: England somewhere.
doogles liked this post



Return to Astronomy & Cosmology

Who is online

Users browsing this forum: No registered users and 7 guests