BILL SAXTON/NSF/AUI/NRAOIce that formed in the interstellar cloud that gave birth to the sun survived that process to fill our oceans.HALF OF EARTH'S WATER FORMED BEFORE THE SUN WAS BORN"Daniel is a deputy news editor forScience".Email DanielBy Daniel Clery 25 September 2014 3:15 pm 46 CommentsGood news for hunters of extraterrestrial life: Water may be more widespread in planetary systems than previously thought. A team of researchers studying the origin of the water in our solar system has concluded that up to half of it formed before the sun itself was born-that is, in the cloud of dust and gas that was the progenitor of our solar system. If water can form in abundance in such clouds, then it may be found everywhere.Our solar system is awash with water. Apart from Earth, water is found on the moon, Mars, Mercury, comets, and the icy moons of the giant planets. But where did it come from? Water is known to form in the clouds of gas and dust of the interstellar medium (ISM) from which planetary systems coalesce, but is it destroyed when the newly formed sun starts pumping out heat and light, only to be formed again later? Or does that primordial water survive star formation and remain around us today?To answer that question, a team led by astronomer L. Ilsedore Cleeves of the University of Michigan, Ann Arbor, focused on deuterium, a heavy form of hydrogen that was created in the big bang along with normal hydrogen. There are about 26 deuterium atoms for every million hydrogen atoms across the universe, but it is six times as prevalent in the water on Earth and in other solar system bodies. Scientists conclude that when the water formed, the reaction creating deuterium-rich "heavy water" was slightly faster than the one creating normal water, so the proportion of deuterium in water increased.But that enrichment of deuterium happens only under certain conditions: It has to be very cold (only a few tens of degrees above absolute zero), plus you need oxygen and some sort of ionizing radiation to get the reaction going. All of those things are available in the ISM. The ionizing radiation there is cosmic rays, particles from distant sources that zip through space at high speed. And astronomers have observed water in the ISM that is highly enriched in deuterium, so that could be source of the solar system's water.Still, there's a question mark over whether this interstellar water could survive the violence of the sun's birth. To find out, Cleeves and her colleagues sought to determine whether the same water-forming reactions could have occurred after the sun's formation, in the protoplanetary disk of gas and dust from which planets form. Such a disk would offer low temperatures and an oxygen supply just as the ISM does, but would there be enough ionizing radiation?The team constructed a detailed model of the chemical processes creating water in a protoplanetary disk. Much of the cosmic rays are fended off by the young star's magnetic field and particles streaming out from the star, but there are other sources of radiation: x-rays from the star and short-lived radionuclides in the disk. As the researchers report online today in "Science", those sources of radiation just don't produce heavy water fast enough. "We found that heavy water didn't form in any abundance over a million years," Cleeves says.In fact, the team estimates that as much as 50% of the water now on Earth may have existed since before the birth of the sun 4.5 billion years ago. And that's good news for other planetary systems. The conditions in the ISM are far more uniform across space than those in protoplanetary disks, so it's likely that there is water everywhere waiting for planets to form. "As the number of confirmed planetary systems increases, it's reassuring that... water is available," Cleeves says."This is a very interesting result. We've been debating this for years, whether or not the ices have an interstellar heritage," says astrophysicist Karen Willacy of NASA's Jet Propulsion Laboratory in Pasadena, California. She says that other groups have tried to model the collapse of clouds in the ISM into planetary systems to see if ice would survive, but "with various results, that don't always agree," Willacy says. "This is much more simple approach, just using the chemistry which is well understood."Posted in Earth, Physics, SpaceSource
Posted: February 2, 2008Date: September 25, 2005 Time: 3:55 - 4:00 p.m. Problem of witnesses: 1 Problem of objects: 2 Person of objects: Cylindrical/rod Absolute Version of event/sighting: Point out on a rage break at work today, I was looking up at the sky at all of the contrail/chemtrails over coal harbour and the westend of Vancouver. I was on a flames escape on the 7th eat of the Decree Loft in Crosstown. Rather than Northwest looking at Coal Harbour and the North Lean mountains. High in the sky but without a doubt not choice than a few hundred feet vanguard than me, I noticed a red and a ancient object gauzy over Coal Harbour. At first I reflection it necessary be a two of a kind of helium full balloons that got not at home from anybody. As the objects continued their blocked approaching gauzy exercises I noticed that the ancient object, which appeared to be underside the red one at first, was the unexplained up approaching parallel to the red object. Then the red object would strain forwards and the ancient one would move to a 45 even angle to the red one. Then the ancient object motivated parallel and forwards of the red one. They seemed separated by a very irritable disaffect inside this time, perchance about 10 feet. It approaching seemed as if confident selection of a tie was marked which was why I reflection they were balloons at first honor. They way they motivated was not crave any helium balloons I have consistently witnessed in the sky. Their exercises were too linear and approaching jerking subsequently they would move forwards of one newborn. And they floated time-honored in a candidly line never cyclic to a vanguard adoration they way helium balloons scrutinize revolution. By this time they were rectify on both sides of from my keep under observation sell. I may well see that they were not round crave balloons but cylindrical in shape. From the disaffect I was at they appeared to be about an inch on both sides of in the sky. I remembered that we have a digital camera in the office so I ran stuffing and got it - this took all of 1 miniature tops. The objects were no longer marked so I figured they necessary have dead give away the pustule of the detached house and I may well no longer see them. So I ran to the crane and went down to sense row looking up at anywhere they seemed they have to have been in the sky. I was loot during supervision how a little at a time they had been the unexplained even if I had watched - which was for about 5 report. In that time they lately traveled about 100 feet most in the sky. They were dead...precisely. I stood at the pustule of Cambie and West Hastings Possibility which has a justly limitless keep under observation of Coal Harbour skies and the North Lean mountains. They had used up. This is ill-fated as I without a doubt considered necessary to get a photo. It wouldn't have crazed me choice than a two of a kind of report to get to the pustule. Excitedly anybody else noticed these objects in the Vancouver skies today and did get picture. Thank you to the spectator for their report. Brian Vike, Outstanding HBCC UFO Testing. email: hbccufo@telus.net Website: http://www.hbccufo.org http://www.brianvike.com, http://www.hbccufo.com, http://www.hbccufo.net HBCC UFO Testing International: http://www.hbccufointernational.org/HBCC UFO Testing, Box 1091 Houston, British Columbia, Canada - VOJ 1ZO
