Suggests comet bombardment contributed to forming oceans
From the European Space Agency: Did Earth’s oceans come from comets?
ESA’s Herschel infrared space observatory has found water in a comet with almost exactly the same composition as Earth’s oceans. The discovery revives the idea that our planet’s seas could once have been giant icebergs floating through space.
The origin of Earth’s water is hotly debated. Our planet formed at such high temperatures that any original water must have evaporated. Yet today, two-thirds of the surface is covered in water and this must have been delivered from space after Earth cooled down.
Comets seem a natural explanation: they are giant icebergs travelling through space with orbits that take them across the paths of the planets, making collisions possible. The impact of comet Shoemaker-Levy 9 on Jupiter in 1994 was one such event. But in the early Solar System, when there were larger numbers of comets around, collisions would have been much more common.
However, until now, astronomers’ observations have failed to back up the idea that comets provided Earth’s water. The key measurement they make is the level of deuterium – a heavier form of hydrogen – found in water.
All the deuterium and hydrogen in the Universe was made just after the Big Bang, about 13.7 billion years ago, fixing the overall ratio between the two kinds of atoms. However, the ratio seen in water can vary from location to location. The chemical reactions involved in making ice in space lead to a higher or lower chance of a deuterium atom replacing one of the two hydrogen atoms in a water molecule, depending on the particular environmental conditions.
Thus, by comparing the deuterium to hydrogen ratio found in the water in Earth’s oceans with that in extraterrestrial objects, astronomers can aim to identify the origin of our water.
All comets previously studied have shown deuterium levels around twice that of Earth’s oceans. If comets of this kind had collided with Earth, they could not have contributed more than a few percent of Earth’s water. In fact, astronomers had begun to think that meteorites had to be responsible, even though their water content is much lower.
Now, however, Herschel has studied comet Hartley 2 using HIFI, the most sensitive instrument so far for detecting water in space, and has shown that at least this one comet does have ocean-like water.
“Comet Hartley’s deuterium-to-hydrogen ratio is almost exactly the same as the water in Earth’s oceans,” says Paul Hartogh, Max-Planck-Institut für Sonnensystemforschung, Katlenburg-Lindau, Germany, who led the international team of astronomers in this work.
The key to why comet Hartley 2 is different may be because of where it was born: far beyond Pluto, in a frigid region of the Solar System known as the Kuiper Belt.
The other comets previously studied by astronomers are all thought to have formed near to Jupiter and Saturn before being thrown out by the gravity of those giant planets, only to return much later from great distances.
Thus the new observations suggest that perhaps Earth’s oceans came from comets after all – but only a specific family of them, born in the outer Solar System. Out there in the deep cold, the deuterium to hydrogen ratio imprinted into water ice might have been quite different from that which arose in the warmer inner Solar System.
Herschel is now looking at other comets to see whether this picture can be backed up.
“Thanks to this detection made possible by Herschel, an old, very interesting discussion will be revived and invigorated,” says Göran Pilbratt, ESA Herschel Project Scientist.
“It will be exciting to see where this discovery will take us.”
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To my mind, this is a leap of faith when so little is really known.
It is one of many small pieces of information gleaned and while one can speculate theories, that doesn’t make them absolute fact.
Water, as we think of it, is a clear fluid or gas as steam). Within the chemical concepts of geology water itself, is a component of minerals, sometimes in a high percentage. Under pressure, water with a high content of dissolved minerals or perhaps it is more illustrative to suggest that water is dissolved in the magma and it does not resemble water to us.
What I’m stating is that the early earth could certainly have retained substantial water content even if all of it’s atmosphere was stripped away by solar activity (another speculation theory).
What we need is more data before anyone decides they know what happened or how it happens. All we really know know right now is that Earth’s water has many sources.
To steal someone else’s lines recently.
“More study is needed” Send money!
“The origin of Earth’s water is hotly debated. Our planet formed at such high temperatures that any original water must have evaporated.”
Where did it get the requisite escape velocity to leave the planet?
‘All the deuterium and hydrogen in the Universe was made just after the Big Bang, about 13.7 billion years ago,…………..’
About 3.00 p.m. on a Thursday wasn’t it? You sound convinced on the Big Bang theory, Anthony. The trouble with the theory is that you have to believe in their ‘singularity’ – a point without dimension – nothing – out of which came an almighty lot of something. They have to have a beginning and an end, not having imagination enough to consider simple eternity.
Tom_R says:
Really? How do you explain the absence of thousands of new impact craters on the moon if it were being impacted by house-sized comets every minute or so (or even every hour to more than account for the lower gravity and smaller cross-section)?
I assume there is lots of impact evidence. The density and size of the comets would make the impact footprint difficult to find unless you knew what you were looking for. And you would have to look… Has anyone looked? I don’t think we are talking about craters.
A G Foster says:
October 6, 2011 at 1:13 pm
Pontification: The “firmament” of Genesis seems to have been
Your “private interpretation” of the Scriptures is utter nonsense. You have no idea what you are talking about.
A few questions:
1) Who taught whom that the world is round: did the Greeks teach the Jews or did the Jews teach the Greeks?
2) How is it that day and night alternated before the creation of the sun?
3) How old are the stars? Why can we see them?
This was hardly a “private interpretation”: it’s the standard critical view and has been for over a century. And it is well known that the Greeks, Romans, Babylonians, and everyone else anciently considered daylight to dawn independently of the sun. Venus was the true harbinger of dawn, and so in Greek it was called “heosphoros,” the “dawn bringer.”
But I don’t expect to be able to talk any sense into someone who takes the flood myth seriously–CAGW is a thousand times more scientific than that. –AGF
Let’s make another leap. That these ice-comets contained microbes that seeded the earth with its first lifeforms. Not an original thought, I know – but one that instantly sprung to mind whilst reading the article.
Tom_R says:
“Really? How do you explain the absence of thousands of new impact craters on the moon if it were being impacted by house-sized comets every minute or so (or even every hour to more than account for the lower gravity and smaller cross-section)?”
From site at http://smallcomets.physics.uiowa.edu/www/faq.htmlx
If you remember that the small comets are like fluffy snowballs–not rocks–the Moon does not present a problem to the existence of small comets. It’s the difference between throwing a rock at your car and a snowball; one will leave a permanent mark, the other will not. Because the Moon is one thirteenth as large as the Earth it should receive about thirteen times fewer objects than the Earth. But the seismometers that were set up on the Moon during the Apollo missions recorded only about 2,000 events a year. How to account for this apparent discrepancy? The small comets do impact the Moon, but the seismometers were calibrated by looking at the seismic signature of everything from nuclear explosions to bullets shot into loose sand. No one ever worked out what effect a large snowball would have on the lunar surface. The small comets that strike the Moon will not make impact craters;they probably kick up some lunar dust and produce strange glows, and indeed these kinds of anomalous events have been reported by lunar observers for centuries. It is the seismometers’ lack of sensitivity to the impact of small comets that accounts for the discrepancy in the low number of large objects detected on the Moon relative to the number of such objects that are seen falling into Earth’s atmosphere. But if small comets strike the Moon, where is all the water then? The lunar gravity is such that practically all the water vapor from the impact of small comets simply flies off, though some of the water molecules may wander around and eventually condense in the crevices near the poles–exactly where it has been reported of late.
A powdery snowball hurled 10 miles a second will leave a mark on my face, and I think on the face of the moon. And the landscape can sit untouched for a million years. I find it hard to believe there woiuld be no trace of these little cometisimiles on the lunar surface. –AGF
http://smallcomets.physics.uiowa.edu/wp.html
The above link from kramer at October 6, 2011 at 1:02 pm is a good one, because if what Dr. Louis A. Frank has proposed for the last 25 years is true, then there are other explanations for the slight rise in sea levels that that which Dr. Al Gore has proposed.
Of course the amounts of water deposition by small comets are difficult to assess, at least by “Simple High School Physics” standards.
One thing is for sure, that was truly a Climate Change Disruption, and it was certainly not human made.
haha!
Frank estimates an inch of rise in 20,000 years: http://smallcomets.physics.uiowa.edu/faq.htmlx
>> A G Foster says:
October 6, 2011 at 3:11 pm
A powdery snowball hurled 10 miles a second will leave a mark on my face, and I think on the face of the moon. And the landscape can sit untouched for a million years. I find it hard to believe there woiuld be no trace of these little cometisimiles on the lunar surface. –AGF <<
Exactly. Even if the density were only 0.1 gm/cm3, a comet the size of a house would have a mass of 100,000 kg, and the energy at impact would be equivalent to about 1 kiloton of TNT. That's not a Barringer-sized crater, but it would leave a visible crater.
A. Viirlaid says: October 6, 2011 at 3:14 pm
http://smallcomets.physics.uiowa.edu/wp.html
…if what Dr. Louis A. Frank has proposed for the last 25 years is true…
I thoroughly recommend Dr Frank’s book “The Big Splash”. Alas, it is out of print and both unavailable and un-reviewed at Amazon. It gives a spirited account of being rubbished because one is challenging the status quo. I see I am a lucky owner. But to quote from the page above, Dr Frank’s own words:
ATTITUDES SOUND FAMILIAR????????????
When magma cools it expels water. The earths crust is ~30km+ thick, when this crust cooled the water was expelled and formed the oceans. It is also constantly recycled with plate tectonics. Sorry, it doesnt come form space. Most astonomers are not volcanologists and dont know that magmas expel large volumes of water, 30km of crust and 4.6 illion years of plate tectonics is enough to form the earths oceans.
For those wondering about why the moon isn’t getting plastered with comets every day.
http://en.wikipedia.org/wiki/Late_Heavy_Bombardment
I didn’t really read much of the OP because it’s been taught as basic earth science since I was a child that the earth’s water was deposited by comets in the late heavy bombardment and everything we’ve discovered since then merely adds confirming evidence to the theory.
The comets are trying to drown us?
We’re doomed!
thingadonta says:
October 6, 2011 at 4:41 pm
“When magma cools it expels water. The earths crust is ~30km+ thick, when this crust cooled the water was expelled and formed the oceans. It is also constantly recycled with plate tectonics. Sorry, it doesnt come form space. Most astonomers are not volcanologists and dont know that magmas expel large volumes of water, 30km of crust and 4.6 illion years of plate tectonics is enough to form the earths oceans.”
Yeah well most posters here don’t know that the water in those magmas comes from the ocean when crust is recycled back into the mantle at underwater subduction zones.
http://www.nsf-margins.org/Nuggets_Public/Nuggets_Final/SubFac/Plank_Kelley_Grove_Stolper_Newman_Hauri_Wiens_Water_Content.pdf
The earth’s oceans are comet water. Get used to it.
I have always believed that Earth’s water originated from so called “comets” and that water found any where in the solar system all came from the same source. This source is the hypothetical Oort cloud and its derivatives. How water may have formed in the first place is really the first mystery to contemplate. We believe that the matter in the Sun is “second hand” left over scrap material condensed from super nova remnants. This first star, the one that blew up to make our sun and all else, is where we must begin. The funny configuration of re-condensed matter we see as our solar system now is nothing more than the steady result of gravity’s effect on rearranging the super nova trash or more politely, elements and let’s not forget miraculous compounds that include vast amounts of water and hydrocarbons.
Surely many giant celestial icebergs (comets) orbited the infant sun at all allowable orbital planes and great collisions occurred throughout the various stages of accretion Earth and all the other planets underwent to finally result in what we see in our night sky today. Some of these icebergs were enveloped during Earth’s early stages of accretion and were entrained within the ever shifting molten core to be boiled off over and over again in a dynamic ancient steamy atmosphere. And surely many more giant icebergs arrived after Earth’s collision with an errant sister body that resulted in our moon. The watery puddles that remained on the Earth’s surface, we now call oceans.
But why did water form to begin with? How could the original super nova create gold, silver, iron, nickel and water and hydrocarbons?
All we know is that did happen and if our little solar junkyard produced all of this and the human brain, imagine what other nearby solar systems must have fashioned out of their super nova trash.
I wish a giant “comet” would collide with Mars next week so it could regain its lost Oceans. Perhaps we could nudge a giant dirty iceberg out of orbit so that it might happen.
@Tom R and the general discussion –
I would take a small leap here and guess the overall number of comets from the early days of the solar system’s formation is greatly lessened from planets/moons “absorbing” them in the form of impacts, which certainly would have been a much more common event in the distant past? The amount of craters on the moon, to use your example, shows intense activity, more so than we see now . Just because it isn’t now doesn’t mean it wasn’t then. Also, why does the answer have to be either terrestrial or extraterrestrial? Couldn’t it be some of both? And couldn’t comets have been MUCH larger that far back? I assume that the airspace near our orbit (sorry – spacespace just doesn’t sound right) was a mess with materials for accretion, so why not some of that debris being huge chunks of ice? I would think that since comets “bleed” off vapor as they travel, they could have been bigger in the past.
Apologies for the drifty nature of the post but I have to go put the kids in bed and I don’t type very fast…
Do I read correctly that this research proposes that comets are mostly water, so are Earth’s oceans, therefore comets made our oceans directly? I cannot believe any of this.
Comets are not composed of water that contains 20,000 ppm sulfate, chloride, sodium, calcium, and magnesium. No, no, no. Our oceans are the result of outgassing from volcanoes. Ocean water has been recycled over the earth’s surface and through the crust many times. Did comets provide a significant amount of water to the primordial Earth? Maybe, but there are other possibilities here too.
Reply to DSW October 6, 2011 at 6:47 pm
My comments were skeptical of the theory that Earth’s water is from house-sized comets that continually and currently still bombard the Earth. In the early solar system, large bodies with lots of ice (call them comets if you will) no doubt contributed to the water on Earth.
IMO, any theory that states where Earth’s water came from, also has to account for the CO2, since both are volatile ices. Earth’s CO2 was converted mostly to carbonates in the ocean, but we can guess that Venus was formed from roughly the same materials and should have the same proportion of volatiles. IIRC, Venus has four times more nitrogen than Earth, so as a first guess I’d say that Earth had about 1/4 the CO2 of Venus before it became carbonates (possibly Earth started with more CO2 and nitrogen but lost much of it’s atmosphere in the collision that created the moon). This gives the Earth a total original mass of CO2 of 1.2^1020 kg, compared to the estimate of 1.6×10^21 kg of water. If comets contain about 8% CO2 by mass compared to H2O, then comets could explain the water on earth. I expect that CO2 would be lost more quickly than H2O as comets outgassed each perihelion, so earlier in Earth’s history comets should have been richer in CO2. Does that account for the 8%?
A G Foster says:
October 6, 2011 at 2:37 pm
A few questions:
1) Who taught whom that the world is round: did the Greeks teach the Jews or did the Jews teach the Greeks?
The idea that the earth is flat, or that the sun revolves around the earth, has no basis in the Scriptures. Likewise with “seven days of creation”.
2) How is it that day and night alternated before the creation of the sun?
They did?
3) How old are the stars?
I dunno. By some estimates, some > 14B years?
Why can we see them?
Eyeballs. What do these questions have to do with anything?
This was hardly a “private interpretation”: it’s the standard critical view and has been for over a century.
“Private” meaning belonging to you. Your own. Glad you brought up the consensus, it must be true. I should quit?
You should take the time to adequately assess the basis for those “critical views” with the same verve and tenacity with which a real scientist tackles his work. Perhaps more so. Better yet, throw out those crap for commentaries you have, and learn how to read the book yourself.
If God is the author of the Scriptures, and he needed someone to comment upon them so you could understand them, he wouldn’t be much of a God, would he? Nonetheless, you should be willing to admit that you have no idea how to read them, since you, like every one of us, has not been taught how to read particularly well.
And it is well known that the Greeks, Romans, Babylonians, and everyone else anciently considered daylight to dawn independently of the sun.
Everyone? You’re sure of that? You interviewed them all?
But I don’t expect to be able to talk any sense into someone who takes the flood myth seriously–CAGW is a thousand times more scientific than that. –AGF
Exactly what sense are you talking about? What flood myth you are talking about?
The myths and fairy tales told and retold about what all people in the past believed or didn’t believe is what rivals the story telling of CAGW. The private interpretations (which are also called lies) that people and organizations have promulgated over the centuries regarding what the Scriptures say has caused more harm to people than all scientific misunderstandings put together for all time.
The deliberate mishandling of the Scriptures, and the deliberate mishandling of climate science observations has fascinating parallels. Both are employed to deceive, defraud, and enslave people. A case can be easily made that they both originate from the same source.
There is not (nor, dare I say, will there ever be) a single scientific fact or observation that contradicts anything in the Scriptures.
Well I’m happy to learn that water is still H2O no matter where you find it. For a while there, I was worried that somebody discovered some water witha different chemical formula. Whew !!
The comet theory is impossible to prove like most other geo origin science. Its relevant what comets are out there now because the comets that would formed the ocean are gone already and of course its an amalgation of many different comets so individual contents of comets don’t even matter- you get some with higher D:H ratios and some lower.