[Science] Space Water or How We Got Oceans

rimrocker · Oct 20, 2011

Huge reservoirs of water vapor just floating around space? That's kind of neat.

Researchers shed light on source of Earth’s water
By Marc Kaufman, Thursday, October 20, 11:02 AM
http://www.washingtonpost.com/natio...lled/2011/10/20/gIQAmBRs0L_story.html?hpid=z6

Water is everywhere on Earth, but nobody has ever been able to determine conclusively how it got here. Scientists know that the very early Earth was far too hot to hold water or water vapor, but then in relatively short geological time the oceans appeared.

In a discovery that researchers say sheds important new light on that age-old question, a European team reported Thursday that it has found a very cold water vapor reservoir that could explain where the water came from.

The region they discovered is at the outer reaches of a dusty disk surrounding a star 175 light-years away. The star and disk are in the early stages of forming planets, much as Earth was formed some 4.5 billions years ago.

The scientists’ conclusion from the new finding: Life-giving H2O was almost certainly delivered to Earth via comets and asteroids known to originate in these cold but water-filled zones, which were assumed to be also present when our solar system was forming.

“Our observations of this cold vapor indicates enough water exists in the disk to fill thousands of Earth oceans,” said astronomer Michiel Hogerheijde of Leiden Observatory in The Netherlands. Hogerheijde is the lead author of a paper describing these findings in the Oct. 21 issue of the journal Science.

“Scientists have long suspected there were these reservoirs of cold water vapor hiding in the outer regions of planet forming disks, but until now we’ve only found signs of water vapor in hot regions closer to the suns,” Hogerheijde said in an interview.

“Since the comets and cold asteroids are formed in the outer reaches, this was a problem for the theory that comets delivered the water to Earth. But now we have the cold reservoir in the region where comets are formed, and so the theory gets considerably stronger.”

The logical extension, he said, is that water has also been delivered to some of the billions of exoplanets now known to exist beyond our solar system, meaning there are likely to be many “ocean worlds” throughout the galaxies.

Hogerheijde said that the 10-million-year old star his team examined, TW Hydrae, is the closest planet-forming star yet identified.

Signs of the cold water vapor were detected by the Herschel Space Observatory, a European Space Agency satellite that looks for infrared light in the galaxy using the Heterodyne Instrument for the Far-Infrared, or HIFI. Efforts to find the cold water vapor in the past all failed because the instruments weren’t powerful enough to pick up the faint spectroscopic signals.

NASA also partially funds Herschel, and American researchers were part of the team. “It is a testament to the instrument-builders that such weak signals can be detected,” said Paul Goldsmith, NASA project scientist for the Herschel Space Observatory at the agency’s Jet Propulsion Laboratory in Pasadena, Calif. “These are the most sensitive HIFI observations to-date.”

According to Hogerheijde, the cold water vapor detected is a small portion of the “ice reservoir” existing in the region. The ice crystals, which cover the widespread dust particles, form in conditions reaching minus-400 degrees Fahrenheit. But ultraviolet light from the star warms the ice enough to briefly release the vapor that was detected, Hogerheijde said.

The announcement comes just weeks after a related finding that the water in some comets has the same chemical composition of the Earth’s oceans. Previous detections had found water with a different isotopic make-up, suggesting that no more than 10 percent of the Earth’s water was delivered by comet.

But data from the comet Hartley 2 found the ratio of heavy hydrogen (deuterium) to ordinary hydrogen to be almost exactly what it is in the Earth’s oceans. “Now, in principle, all the water (in the Earth’s oceans) could have come from comets,” said principal investigator Paul Hartogh of Germany’s Max Planck Institute.

Planetary scientists have determined that huge amounts of graphite and silicon dust surround stars as they form and that material over time binds together to former larger bodies such as comets and asteroids and — around many stars — ultimately planets.

Earth formed some 4.5 billion years ago, they have concluded, and was then too close to the sun to hold much water or water vapor. But around 4.1 billion years ago began a period of “heavy bombardment,” when Earth was pummeled by comets and cold meteorites from the outer reaches of its disk, both of which carry water.

The bombardment ended by about 3.8 billions years ago, and at that point much of the Earth’s water was in place. The earliest forms of microbial life detected so far lived some 3.6 billion years ago, a relatively short geological period after the oceans had filled.

While there is growing evidence for the explanation that comets and wet asteroids delivered our oceans, some researchers hold that the water came primarily from other sources. For instance, water is believed to have been released from early volcanos that belched up molten material from deep in the Earth, including H2O. Water could also leak out of certain minerals in rocks as the planet cooled.

Hogerheijde said that while this early “outgassing” most likely played a role in making early Earth wet, the evidence is now persuasive that much of the water for our oceans was later delivered from afar.
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boomboom · Oct 20, 2011

Very interesting. What amazes me is that the answer to almost any astronomical question bombarding us on a constant basis...we just don't have the capability (or proper tools) to detect the answers. Imagine what we could do if we (as a planet) could get our **** in gear, stop fighting and focus resources on much more interesting (and beneficial) things such as this rather than continue with ridiculous conflicts. smh.

Nice post rimrocker!

Thefabman · Oct 20, 2011

inb4 religions and toycens...

Rashmon · Oct 20, 2011

Very interesting. Your post reminded me of this related article I read recently...

First Comet Found With Ocean-Like Water

ScienceDaily (Oct. 5, 2011) — New evidence supports the theory that comets delivered a significant portion of Earth's oceans, which scientists believe formed about 8 million years after the planet itself.

The findings, which involve a University of Michigan astronomer, are published Oct. 5 online in Nature.

"Life would not exist on Earth without liquid water, and so the questions of how and when the oceans got here is a fundamental one," said U-M astronomy professor Ted Bergin, "It's a big puzzle and these new findings are an important piece."

Bergin is a co-investigator on HiFi, the Heterodyne Instrument for the Infrared on the Hershel Space Observatory. With measurements from HiFi, the researchers found that the ice on a comet called Hartley 2 has the same chemical composition as our oceans. Both have similar D/H ratios. The D/H ratio is the proportion of deuterium, or heavy hydrogen, in the water. A deuterium atom is a hydrogen with an extra neutron in its nucleus.

This was the first time ocean-like water was detected in a comet.

"We were all surprised," Bergin said.

Six other comets HiFi measured in recent years had a much different D/H ratio than our oceans, meaning similar comets could not have been responsible for more than 10 percent of Earth's water.

The astronomers hypothesize that Hartley 2 was born in a different part of the solar system than the other six. Hartley most likely formed in the Kuiper belt, which starts near Pluto at about 30 times farther from the sun than Earth is. The other six hail from the Oort Cloud more than 5,000 times farther out.

The source of earth's oceans has been a subject for debate among astronomers for decades. Until now, asteroids were thought to have provided most of the water. Now, however, Herschel has shown that at least one comet does have ocean-like water.

"The results show that the amount of material out there that could have contributed to Earth's oceans is perhaps larger than we thought," Bergin said.

Herschel, a European Space Agency mission with NASA participation, is an orbiting telescope that allows astronomers to observe at the far-infrared wavelengths where organic molecules and water emit their chemical signatures.

http://www.sciencedaily.com/releases/2011/10/111005131654.htm

Jimes · Oct 20, 2011

Thefabman said: ↑

inb4 religions and toycens...
Click to expand...

Now that you've asked so nicely:
Genesis 1
6 And God said, “Let there be an expanse between the waters to separate water from water.” 7 So God made the expanse and separated the water under the expanse from the water above it. And it was so. 8 God called the expanse “sky.” And there was evening, and there was morning—the second day.

Not that I'm jumping to the conclusion that the article supports the verse, just thought the connection is kinda interesting.

Keyser Soze · Oct 20, 2011

Ah, the mystery of space. Nice read

Fyreball · Oct 20, 2011

Between this and all of the new information they've found regarding neutrinos, this has been a pretty fascinating few months. Very cool!

Cowboy_Bebop · Oct 20, 2011

Also came across this today.
http://www.jpl.nasa.gov/news/news.cfm?release=2011-322

NASA's Spitzer Detects Comet Storm in Nearby Solar System
October 19, 2011

PASADENA, Calif. -- NASA's Spitzer Space Telescope has detected signs of icy bodies raining down in an alien solar system. The downpour resembles our own solar system several billion years ago during a period known as the "Late Heavy Bombardment," which may have brought water and other life-forming ingredients to Earth.

During this epoch, comets and other frosty objects that were flung from the outer solar system pummeled the inner planets. The barrage scarred our moon and produced large amounts of dust.

Now Spitzer has spotted a band of dust around a nearby bright star in the northern sky called Eta Corvi that strongly matches the contents of an obliterated giant comet. This dust is located close enough to Eta Corvi that Earth-like worlds could exist, suggesting a collision took place between a planet and one or more comets. The Eta Corvi system is approximately one billion years old, which researchers think is about the right age for such a hailstorm.

"We believe we have direct evidence for an ongoing Late Heavy Bombardment in the nearby star system Eta Corvi, occurring about the same time as in our solar system," said Carey Lisse, senior research scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., and lead author of a paper detailing the findings. The findings will be published in the Astrophysical Journal. Lisse presented the results at the Signposts of Planets meeting at NASA's Goddard Space Flight Center in Greenbelt, Md., today, Oct. 19.

Astronomers used Spitzer's infrared detectors to analyze the light coming from the dust around Eta Corvi. Certain chemical fingerprints were observed, including water ice, organics and rock, which indicate a giant comet source.

The light signature emitted by the dust around Eta Corvi also resembles the Almahata Sitta meteorite, which fell to Earth in fragments across Sudan in 2008. The similarities between the meteorite and the object obliterated in Eta Corvi imply a common birthplace in their respective solar systems.

A second, more massive ring of colder dust located at the far edge of the Eta Corvi system seems like the proper environment for a reservoir of cometary bodies. This bright ring, discovered in 2005, looms at about 150 times the distance from Eta Corvi as the Earth is from the sun. Our solar system has a similar region, known as the Kuiper Belt, where icy and rocky leftovers from planet formation linger. The new Spitzer data suggest that the Almahata Sitta meteorite may have originated in our own Kuiper Belt.

The Kuiper Belt was home to a vastly greater number of these frozen bodies, collectively dubbed Kuiper Belt objects. About 4 billion years ago, some 600 million years after our solar system formed, scientists think the Kuiper Belt was disturbed by a migration of the gas-giant planets Jupiter and Saturn. This jarring shift in the solar system's gravitational balance scattered the icy bodies in the Kuiper Belt, flinging the vast majority into interstellar space and producing cold dust in the belt. Some Kuiper Belt objects, however, were set on paths that crossed the orbits of the inner planets.

The resulting bombardment of comets lasted until 3.8 billion years ago. After comets impacted the side of the moon that faces Earth, magma seeped out of the lunar crust, eventually cooling into dark "seas," or maria. When viewed against the lighter surrounding areas of the lunar surface, those seas form the distinctive "Man in the Moon" visage. Comets also struck Earth or incinerated in the atmosphere, and are thought to have deposited water and carbon on our planet. This period of impacts might have helped life form by delivering its crucial ingredients.

"We think the Eta Corvi system should be studied in detail to learn more about the rain of impacting comets and other objects that may have started life on our own planet," Lisse said.

NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the Spitzer mission for the agency's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.
Click to expand...

So pretty much we don't really have to worry too much about running out of water if we have the technology to mine them on a particular planet that we plan to settle on.

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[Science] Space Water or How We Got Oceans

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