Slashdot Mirror
Asteroid Crashes Likely Gave Earth Its Water
Diggester writes "Asteroids from the inner solar system are the most likely source of the majority of Earth's water, a new study suggests. The results contradict prevailing theories, which hold that most of our planet's water originated in the outer solar system and was delivered by comets or asteroids that coalesced beyond Jupiter's orbit, then migrated inward."
So rocks carrying massive amounts of water magically came to the Earth?
This can't be good for Space Nutters. One of their main points of their religion is in doubt now. Coupled with the fact that the DSM-V now describes a general anxiety disorder that can very well cover Space Nuttery, looks like a cure is just around the corner.
That's the simplest explanation. You nerds and your crazy ideas !!
The four Elephants contributed a lot less.
Humanity's very existence is proof against Intelligent Design.
Truth isn't Truth - Guliani
Hmmm.
Also it must have been hit by a whole heck of a lot of spacerocks, since 2/3rds of the surface is water. That's a lot of impacts.
My AC stalker: " I personally agree with your posts most of the time, but that won't keep me from modding you troll"
If this is true then how much water does the moon have? It seems like that should be estimable and relevant to the future if space travel if we assume all the earths water came during the late heavy bombardment. It also could be a good way to test this theory. If concentrations of water on the moon don't correlate wouldn't that poke some holes in the theory?
Wow, you'r right. Why do we spend all this time, effort and money investigating things when the answer is so obvious...
If you could reason with religious people, there would be no religious people
We need one more Asteroid when our wells start running dry
Wait, so asteroid impacts are good now?
I mean, look at what we see with other protostars forming out there; the compaction of gasses from nebulae... and with the building blocks of water being so extremely common out there (contrary to the plot of 'ice pirates') its only natural that water will condense into these protosystems as well... and water has a tendency to build up a static charge, which would probably influence its distribution, especially in 'warmer' parts of the forming system. I would resume that it would congregate easier closer in, and most of what is found in the outer system (oort and kuiper type structures) may be what was thrust out there by the 'ignition (for lack of a better term)' of the new star. It's all speculation, but based on observations.
IANAA (I Am Not An Astrophysicist), but that's interesting.
What's the mechanism by which this is presumed to be the case?
In lieu of an actual answer, I'll throw out a hypot^H^H^H^H^Hwild-ass-guesse: in a collapsing cloud initially composed of a mix of hydrogen and deuterium, the heavier deuterium will wind up sinking into the part of the cloud that becomes part of the star, leaving the parts of the cloud that were closest to the star (but which didn't fall into the star before it ignited) deuterium-depleted.
If I was the creator of the universe, and had billions of trillions of planets capable of supporting life, what would be the most efficient 'delivery system' for me to use to deliver the "Seeds of Life" to them all? Frozen water. Lots of iceballs with the 'seeds of life' in them. Since all life on earth is based on water, and water is not native to earth, all of our water came from 'out there'. So, if life sprouted on this planet, it stands to reason it's happened everywhere. Ergo, we most likely are not 'alone'.
Why is it that water had to come from elsewhere, exactly?
I mean, if it could form on comets or asteroids, why could it not have formed right here on Earth the same way it forms elsewhere? Why is there such a predisposition to the notion that water must have come from somewhere else?
File under 'M' for 'Manic ranting'
That's the simplest explanation. You nerds and your crazy ideas !!
Best possible explanation for unplanned pregnancies.
Sheesh, evil *and* a jerk. -- Jade
That ball of acid and CO2 could really benefit from some H2O. So there's the new terraforming plan: paint a bullseye on Venus, and they'll come...
Ok, just to get it out of the way, here's the obligatory question: This happened millions of years ago! How is it news for nerds?
p.s. anyone who answers this as if it were a legitimate question shall be dunked into a tank full of melted asteroids. :)
"The inner Solar System, the region of the Solar System inside 4 AU, was too warm for volatile molecules like water and methane to condense, so the planetesimals that formed there could only form from compounds with high melting points, such as metals (like iron, nickel, and aluminium) and rocky silicates. " --Formation of planets
That took me like two minutes of searching to find. You could have found it in little more than double the amount of time it took you to type up your post.
What? Do these people even THINK about the stupid theories they come up with?
We call Earth a water planet. It seems preposterous that a bunch of rocks could bring in enough water to fill Earth’s lakes, rivers and oceans.
Yet Earth, in terms of its overall mass, is 0.06% water. With about 70% of its surface covered in water, Earth is considerably drier than it appears.
HRH The Duke of Windsor
Wow, you'r right.
Wow. Just... wow.
According to quick Google, average depth of oceans is about 4km, surface area of earth is about 510'072'000 km2 and water covers about 70% of earths surface.
5.1E8 km2 * 4km * 0.7 = 1.428 billion km3. Sphere of that volume is about 1396 km across.
The GP's graph says "1390 kilometres across and has a volume of 1.4 billion cubic kilometres", which is very close to that quick approximation.
My approximation is very quick and dirty (I didn't take into account that surface of earth is less 4km below the surface than on the surface, which would reduce the sphere... but I also didn't take into account glaciers, etc. which would increase the sphere... Obviously the surface of sea isn't exactly 70% and the depth isn't exactly 4km...) but I feel very confident that the scale of the number is about right and it happens to perfectly match the graph.
When the Earth was first being formed, the whole region of the nebula was far to hot for water to condense. So, the original rock was mostly just heavy metals and such.
A little further away from the sun, the relative abundance of hydrogen and oxygen made for excellent conditions for the formation of water, which eventually became huge icy asteroids. They are still out there, in fact. Some of them crashed into the Earth though, where the water melted and became our oceans.
That is, of course, an oversimplification, but it answers your questions. The water was out there, and not right here, because of the temperature gradient that was present when our solar system was young. The model explains where the water came from, too, but if you play the "and where did THAT come from" game you eventually get to the big bang. The model doesn't say much about what happened before the big bang because we have no means of gathering any data about such a period.
So, the reason you don't see the rationale is mainly because you haven't done your homework. You don't actually understand the model you are attacking, and you are unaware of the data and arguments in defense of that model. So, we would expect that you don't find the conclusions compelling. But, of course, if you bothered to learn the facts rather than just form opinions, you might find the reasons more convincing (provided you are basically intelligent, that is).
Also, your definition of religion seems a bit odd. The key differences between science and religion are:
1) Proponents of science base their claims on observations and evidence, whereas religious followers base their claims on ancient myths.
2) Scientific models are changed when new data come to light, whereas religions teachings just reject all contrary evidence as lies, no matter how compelling.
Whether or not something is said to have come from "far away" seems irrelevant.
One day the Earth was so thirsty it asked Space for a drink. Space provided with a steady stream of nicely iced drinks. Eventually the Earth became so drunk that all kinds of creatures appeared.
http://news.nationalgeographic.com/news/2011/06/110613-space-science-star-water-bullets-kristensen/
Done and done. It's shown that most stars do this.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
I once had a quick-link to a paper on the topic – but there is a fringe of geologists that speculate how water could from from liberated oxygen and hydrogen deep within the mantle. Basically, the earth 'sweating' water from the core, outward.
It hard to imagine (statistically) that all of earth's water... such a huge volume, was from icy balls (comets) striking the planet.....
And the xistians will use this as evidence of the biblical flood.
Oh, asteroid. Yeah, that makes a bit more sense.
My unprovable theory about what happened billions of years ago can beat up your unprovable theory about what happened billions of years ago!
Where did the ice come from on the asteroids? Were they hit by little wet Earths?
As you must know (or maybe not) water is made of two hydrogen atoms and one oxygen atom. By mass, that means that oxygen is 16 parts oxygen and 2 parts hydrogen. Now, hydrogen is quite simply the most abundant element (from the regular periodic table anyway, who knows if any of the dark matter takes forms that could be classed as "elements") in the entire universe. As a single proton with a single electron, it's the simplest, most basic stable form of baryonic matter. As for the oxygen, it's estimated to be the third most common element in the universe (based on the numbers from spectrographic analysis of our galaxy). There's about 1/71st as much oxygen as hydrogen by mass, which means that there's about 1/1136th as many oxygen atoms as hydrogen atoms. As such, it's not hard for h2 molecules to encounter 02 molecules. When they do so energetically enough, you end up with water. Lots and lots and lots of water. A lot of it ends up mixed up in big celestial bodies, but plenty also accumulates into smaller objects like comets and asteroids. As for the origin of the oxygen, the prevailing and well supported theory is that it was mostly made in red giant stars where four helium (mostly made during the origin of the universe) atoms combined into one oxygen atom.
I don't see the rationale for arguing about water first being seeded in conditions that are mutually exclusive from those that develop a planetary mass on a particular orbit, nor do I see any argument compelling for this, it is another "plan 9" scape-goat (to use a religious term) that says "anything unexplained happened really far away, a really long time ago".
Also, to make things clear, this article isn't really talking about all of Earth's water, it's just talking about most of its surface water. Earth has plenty of other water entrained below the surface from its first formation, and some of the surface water was doubtlessly in the early atmosphere before the planet cooled enough for surface water.
Also "plan 9"? The one where humanoid aliens with really bad silver foil uniforms animate humanities dead (about three individuals worth) in order to take over the world? Ummm, huh?
The ratio of water to rock in an asteroid is lower than the ratio of water to rock on Earth by approximately a whole fucking lot. So this is as idiotic as it sounds. What do scientists think asteroids are structured like, water balloons? Let's see....how else is water made. Oh yeah, expose Hydrogen to heat in the presence of Oxygen. Naw, where would hydrogen and oxygen ever come together and get hot around a planet in space? That's just silly.
Whatever. We got the water- Mars can suck dust. Take that you funny looking green guys!
Vote monkeys into Congress. They are cheaper and more trustworthy.
,why couldn't all/most of the water have been part of the original accretion?
Why would it "boil off", I mean Venus has got loads of water in vapour form, and it isn't losing it into space.
Earth has a strong magnetic field and probably stronger initially because more of the core was molten, and a strong magnetic field prevents ablation of the atmosphere (and hence water vapour) by the solar wind.
This original accreted water would be trapped internally for a long period until squeezed out by the pressures within and being forced to the surface by convection.
Sure it could come from external sources, but why does it necessarily have to have been?
Why is it that water had to come from elsewhere, exactly?
The reasoning can be summed up in one word: Neon. There is almost none of it on Earth, although it is common elsewhere in the Universe, and was almost certainly common in the cloud that formed the Earth and Solar System. Neon has an atomic mass of 20. Water is 18. So when the Earth was young and hot, and didn't have enough gravity to hold onto its neon, it wouldn't have been able to hold onto water vapor either. Therefore the water must have arrived later.
We send a robotic ship up, snag a comet, and plunk it down into the middle of the dessert! INSTANT WATER! LOL.
Not all the water needs to have arrived as water. Water molecules are not eternal. Some of the oxygen and hydrogen could have been in other compound or even elemental when it arrived. There was probably a lot of methane in the early mix that contributed hydrogen and a lot of stone contains oxygen.
At first I read that as "Android crashes" and wondered if only there were some way to harness the power of Windows crashes as well....
Esli epei etot cumprenan, shris soa Sfaha.
The summary sums it up better "The results contradict prevailing theories, which hold that most of our planet's water originated in the outer solar system and was delivered by comets or asteroids".
Whoever wrote 'Asteroid Crashes Likely Gave Earth Its Water' as a news headline should not be allowed to write headlines anymore.
I'd like to know if those space objects, that delivered water, we're salty or fresh?
While the model might work, it still doesn't answer the question : where did the water on the asteroids come from? And furthermore, why is a "foreign" source of water required?
Water comes from two very abundant elements: hydrogen and oxygen - why do they need to come from somewhere else ?
A much more interesting question would be where the heavy post-lead elements came from. In many science textbooks they explain the origin of the heavy elements as coming from the nucleus of stars - yet we see in the earth's crust elements that cannot be formed in the stars - for instance Uranium, which has a half life of several billion years. Furthermore there was no star formation in our near vicinity where the earth is presently - much less stars which could compress their cores to produce the heavy elements. Where did these come from, and is it at all common elsewhere? With such a long half-life it seems that it could serve as a tracer for aging the other planets relative of to the earth.
Anyone know of any articles on this or links to share?