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Galaxy

Significant fraction of water on Earth predate the sun and the solar system - study

© Bill Saxton, NSF/AUI/NRAO
An illustration of the history of origins of water in our solar system. A new study finds it started in the molecular cloud (prior to the Sun's formation), traveled through the stages of star formation, until it wound up in the solar system.
Some of the water molecules in your drinking glass were created more than 4.5 billion years ago, according to new research.

That makes them older than the Earth, older than the solar system - even older than the sun itself.

In a study published Thursday in Science, researchers say the distinct chemical signature of the water on Earth and throughout the solar system could occur only if some of that water formed before the swirling disk of dust and gas gave birth to the planets, moons, comets and asteroids.

This primordial water makes up 30% to 50% of the water on Earth, the researchers estimate.

This finding suggests that water, a key ingredient of life, may be common in young planetary systems across the universe, Cleeves and her colleagues say.

Scientists are still not entirely sure how water arrived on Earth. The part of the protoplanetary disk in which our planet formed was too hot for liquid or ice water to exist, and so the planet was born dry. Most experts believe the Earth's water came from ice in comets and asteroids that formed in a cooler environment, and later collided with our planet.

But this theory leads to more questions. Among them: Where did the water preserved in the comets and asteroids come from?

To find out, scientists turned to chemistry. Here on Earth, about one in every 3,000 molecules of water is made with a deuterium atom instead of a hydrogen atom.
Telescope

Simulations reveal an unusual death for ancient stars

© Ken Chen, UCSC
This image is a slice through the interior of a supermassive star of 55,500 solar masses along the axis of symmetry. It shows the inner helium core in which nuclear burning is converting helium to oxygen, powering various fluid instabilities (swirling lines). This "snapshot" from a CASTRO simulation shows one moment a day after the onset of the explosion, when the radius of the outer circle would be slightly larger than that of the orbit of the Earth around the sun. Visualizations were done in VisIT.
Certain primordial stars -- those between 55,000 and 56,000 times the mass of our Sun, or solar masses -- may have died unusually. In death, these objects -- among the Universe's first-generation of stars -- would have exploded as supernovae and burned completely, leaving no remnant black hole behind.

Astrophysicists at the University of California, Santa Cruz (UCSC) and the University of Minnesota came to this conclusion after running a number of supercomputer simulations at the Department of Energy's (DOE's) National Energy Research Scientific Computing Center (NERSC) and Minnesota Supercomputing Institute at the University of Minnesota. They relied extensively on CASTRO, a compressible astrophysics code developed at DOE's Lawrence Berkeley National Laboratory's (Berkeley Lab's) Computational Research Division (CRD). Their findings were recently published in Astrophysical Journal (ApJ).

First-generation stars are especially interesting because they produced the first heavy elements, or chemical elements other than hydrogen and helium. In death, they sent their chemical creations into outer space, paving the way for subsequent generations of stars, solar systems and galaxies. With a greater understanding of how these first stars died, scientists hope to glean some insights about how the Universe, as we know it today, came to be.

"We found that there is a narrow window where supermassive stars could explode completely instead of becoming a supermassive black hole -- no one has ever found this mechanism before," says Ke-Jung Chen, a postdoctoral researcher at UCSC and lead author of the ApJ paper. "Without NERSC resources, it would have taken us a lot longer to reach this result. From a user perspective, the facility is run very efficiently and it is an extremely convenient place to do science."
Comet

PanSTARRS K1, the comet that keeps going and going and going

Comet C/2012 K1 PanSTARRS
© Rolando Ligustri
Comet C/2012 K1 PanSTARRS photographed on September 26, 2014. Two tails are seen – a dust tail points off to the left and the gas or ion tail to the right.
Thank you K1 PanSTARRS for hanging in there! Some comets crumble and fade away. Others linger a few months and move on. But after looping across the night sky for more than a year, this one is nowhere near quitting. Matter of fact, the best is yet to come.

This new visitor from the Oort Cloud making its first passage through the inner solar system, C/2012 K1 was discovered in May 2012 by the Pan-STARRS 1 survey telescope atop Mt. Haleakala in Hawaii at magnitude 19.7. Faint! On its the inbound journey from the Oort Cloud, C/2012 K1 approached with an orbit estimated in the millions of years. Perturbed by its interactions with the planets, its new orbit has been reduced to a mere ~400,000 years. That makes the many observing opportunities PanSTARRS K1 has provided that much more appreciated. No one alive now will ever see the comet again once this performance is over.
Chalkboard

Open review yields, with the help of bloggers, better discovery of scientific flaws - The Guardian trashes peer review process

© Wattsupwiththat.com
Eric Worrall writes: The Guardian, a green UK newspaper, has published a fascinating article about the shortcomings of peer review - and praised the growing new model of open review, in which papers are pre-published on the internet, giving anyone an opportunity to comment. Naturally the Guardian author was not talking about global warming, which in Guardian circles remains settled science which cannot be questioned, but the point is well made, and well worth reading.

According to The Guardian;
"some scientists would prefer ... that results are announced only after they have passed peer review, ie been checked by experts and published in a reputable journal.

There are many reasons why this will no longer wash. Those days of deference to patrician authority are over, and probably for the better. We no longer take on trust what we are told by politicians, experts and authorities. There are hazards to such scepticism, but good motivations too. Few regret that the old spoonfeeding of facts to the ignorant masses has been replaced with attempts to engage and include the public.

But science itself has changed too. Information and communications technologies mean that not only is it all but impossible to keep hot findings under wraps, but few even try. In physics in particular, researchers put their papers on publicly accessible pre-print servers before formal publication so that they can be seen and discussed, while specialist bloggers give new claims an informal but often penetrating analysis. This enriches the scientific process and means that problems that peer reviewers for journals might not notice can be spotted and debated. Peer review is imperfect anyway - a valuable check but far from infallible, and notoriously conservative."

Scientists got it wrong on gravitational waves. So what?

Comment: See also: Peer review: the myth of the noble scientist

Blue Planet

Did an underwater landslide double the 2011 Japanese tsunami?

tsunami japan 2014
© Hitoshi Katanoda/Polaris/Newscom
Tsunami waves swept over the 10-meter harbor wall at Taro, Iwate, Japan. Were they produced by a massive undersea landslide?
An underwater landslide the size of the Paris may have triggered the worst of the tsunami that struck Japan on 11 March 2011, a new study claims.

Most of the destruction that day was caused by a 10-meter surge that overwhelmed coastal defenses from south of Fukushima to the northern tip of Honshu island. But along a 100-km mountainous stretch called Sanriku, indented with bays and small harbors, the incoming waves rose to a monstrous 40 meters. About a quarter of the tsunami's 18,000 victims died in those ports, yet experts have struggled to find a satisfactory explanation for the exceptional inundation that killed them.

Seismologist Kenji Satake of the University of Tokyo's Earthquake Research Institute, one of the world's leading authorities on tsunamis, thinks a second earthquake was responsible. This temblor, he says, occurred north of the main submarine thrust, involved a thin sliver of crust, and left no trace in the seismic record of the day.

But Stephan Grilli, an oceanographer at the University of Rhode Island, Narragansett Bay, wasn't convinced. Movements along Earth's faults, he says, don't jolt the sea surface in the right way to focus a band of waves on just a hundred kilometers of coastline, as happened in 2011.
Telescope

A Higgs-Gravity connection may leave traces in white dwarfs

White Dwarf
© NASA, ESA
Image of Sirius A and Sirius B taken by the Hubble Space Telescope. Sirius B, which is a white dwarf, can be seen as a faint pinprick of light to the lower left of the much brighter Sirius A.
The discovery of the Higgs boson at the Large Hadron Collider (LHC) in 2012 marked an important step toward understanding the origin of the mass of fundamental particles. Since mass plays a major role in gravity, the Higgs could also reveal insights into the nature of gravity. One possibility is that the Higgs field could couple to a specific spacetime curvature, a scenario that is invoked in various extensions of the standard model.

Now, scientists have shown that dying stars called white dwarfs can be used to investigate and place limits on the coupling between the Higgs field and spacetime curvature. The study, by Roberto Onofrio at the University of Padova in Italy and the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, and Gary A. Wegner at Dartmouth College in Hanover, New Hampshire, is published in a recent issue of The Astrophysical Journal.

"Conceptually, I think that our work is trying to create a 'common' language between microphysics and macrophysics in the following sense," Onofrio told Phys.org. "So far, people have looked for the consequences of the Higgs field in the microworld, at the so-called Fermi scale, i.e., the attometer scale (1 am = 10-18 m), and for the consequences of gravity at the macroscopic scale, from an apple upward in terms of size and masses. Yet, both have in common the central role that mass plays in the standard model of elementary particle physics and in gravitation. So by starting to talk of masses involving both the Higgs field (which is supposed to give inertial mass to all fundamental particles) and gravitation (where the gravitational mass of a body is a key concept), one can check for their consistency or for the presence of possible contradictions."
Magnify

Human genome: Shaped by an evolutionary arms race with itself?

Human Genome
© LiveScience
New findings by scientists at the University of California, Santa Cruz, suggest that an evolutionary arms race between rival elements within the genomes of primates drove the evolution of complex regulatory networks that orchestrate the activity of genes in every cell of our bodies.

The arms race is between mobile DNA sequences known as "retrotransposons" (a.k.a. "jumping genes") and the genes that have evolved to control them. The UC Santa Cruz researchers have, for the first time, identified genes in humans that make repressor proteins to shut down specific jumping genes. The researchers also traced the rapid evolution of the repressor genes in the primate lineage.

Their findings, published September 28 in Nature, show that over evolutionary time, primate genomes have undergone repeated episodes in which mutations in jumping genes allowed them to escape repression, which drove the evolution of new repressor genes, and so on. Furthermore, their findings suggest that repressor genes that originally evolved to shut down jumping genes have since come to play other regulatory roles in the genome.

"We have basically the same 20,000 protein-coding genes as a frog, yet our genome is much more complicated, with more layers of gene regulation. This study helps explain how that came about," said Sofie Salama, a research associate at the UC Santa Cruz Genomics Institute who led the study.
Galaxy

Gravitational wave detection by frequency matching oscillating stars?

gravitational waves
© Credit: NASA
Energetic events, such as this artist’s rendition of a binary-star merger, are thought to create gravitational waves that cause ripples in space and time.
Scientists have shown how gravitational waves - invisible ripples in the fabric of space and time that propagate through the universe - might be "seen" by looking at the stars. The new model proposes that a star that oscillates at the same frequency as a gravitational wave will absorb energy from that wave and brighten, an overlooked prediction of Einstein's 1916 theory of general relativity. The study, which was published today in the Monthly Notices of the Royal Astronomical Society: Letters, contradicts previous assumptions about the behavior of gravitational waves.

"It's pretty cool that a hundred years after Einstein proposed this theory, we're still finding hidden gems," said Barry McKernan, a research associate in the Museum's Department of Astrophysics, who is also a professor at CUNY's Borough of Manhattan Community College; a faculty member at CUNY's Graduate Center; and a Kavli Scholar at the Kavli Institute for Theoretical Physics.

Gravitational waves can be thought of like the sound waves emitted after an earthquake, but the source of the "tremors" in space are energetic events like supernovae (exploding stars), binary neutron stars (pairs of burned-out cores left behind when stars explode), or the mergers of black holes and neutron stars. Although scientists have long known about the existence of gravitational waves, they've never made direct observations but are attempting to do so through experiments on the ground and in space. Part of the reason why detection is difficult is because the waves interact so weakly with matter. But McKernan and his colleagues from CUNY, the Harvard-Smithsonian Center for Astrophysics, the Institute for Advanced Study, and Columbia University, suggest that gravitational waves could have more of an effect on matter than previously thought.
Fireball 5

Meteor strikes may not be random

Meteor
© NASA
Scientists have found that meteor impacts are not random events but may occur as Earth passes through streams of meteoroids.
Meteor impacts are far less random than most scientists assumed, according to a new analysis of Earth-strike meteors.

The research, reported on the pre-press astrophysics website ArXiv.org, concluded that meteor impacts are more likely to occur at certain times of the year when Earth's orbit takes us through streams of meteoroids.

The majority of meteors analysed hit the Earth in the second half of the year, say the researchers, brothers Carlos and Raúl de la Fuente Marcos of the Complutense University of Madrid.

"This lack of randomness is induced by planetary perturbations, in particular Jupiter's, and suggests that some of the recent, most powerful Earth impacts may be associated with resonant groups of Near Earth Objects and/or very young meteoroid streams," they report.

Meteoroid streams can be generated by the break-up of an asteroid or comet.

A planet or moon can also affect nearby asteroids and meteors, herding them into loose orbits called 'resonant streams', which can be broken up by big planets such as Jupiter and Saturn.

The study is based on 33 meteor impact events detected between 2000 and 2013 by infrasound acoustic pressure sensors, operated by the Comprehensive Nuclear-Test-Ban Treaty Organization.

The sensors are designed to detect clandestine nuclear tests, but also pick up meteor impacts with an explosive energy in excess of a thousand tonnes of TNT.
Blue Planet

China's "Supercave" is the world's biggest cave chamber

© Carsten Peter, National Geographic
The photographer’s lights illuminate the green-hued Getu He river in the Miao Room—considered the world’s second largest cave chamber by area.
China's immense Miao Room cavern, hidden beneath rolling hills and reachable only by an underground stream, is the world's biggest cave chamber, an international mapping team reported on Sunday. (Related: "China's Supercave.")

A laser-mapping expedition funded by the National Geographic Society reported the new measurement at the United Kingdom's national caving conference in Leek this weekend.

Richard "Roo" Walters, a British co-leader of the 2013 international caving expedition conducted under the auspices of China's Institute of Karst Geology in Guilin, reported that the Miao Room Chamber measures some 380.7 million cubic feet (10.78 million cubic meters) in volume. (See: "Empire of Rock" in National Geographic Magazine.)
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