Pulsar Transformed Into Small Planet Made of Diamond Discovered in Milky Way
ScienceDaily (Aug. 25, 2011) — A once-massive star that's been transformed into a small planet made of diamond: that's what astronomers think they've found in our Milky Way.
The discovery, reported in Science, was made by an international research team led by Professor Matthew Bailes, Pro Vice-Chancellor (Research) at Swinburne University of Technology in Melbourne and the 'Dynamic Universe' theme leader in a new wide-field astronomy initiative, the ARC Centre of Excellence for All-sky Astrophysics (CAASTRO).
The researchers, from Australia, Germany, Italy, the UK and the USA, first detected an unusual star called a pulsar using the CSIRO Parkes radio telescope and followed up their discovery with the Lovell radio telescope in the UK and one of the Keck telescopes in Hawaii.
Pulsars are small spinning stars about 20 km in diameter -- the size of a small city -- that emit a beam of radio waves. As the star spins and the radio beam sweeps repeatedly over Earth, radio telescopes detect a regular pattern of radio pulses.
For the newly discovered pulsar, known as PSR J1719-1438, the astronomers noticed that the arrival times of the pulses were systematically modulated. They concluded that this was due to the gravitational pull of a small companion planet, orbiting the pulsar in a binary system.
The pulsar and its planet are part of the Milky Way's plane of stars and lie 4,000 light-years away in the constellation of Serpens (the Snake). The system is about an eighth of the way towards the Galactic Centre from Earth.
The modulations in the radio pulses tell astronomers several things about the planet.
First, it orbits the pulsar in just two hours and ten minutes, and the distance between the two objects is 600,000 km -- a little less than the radius of our Sun.
Second, the companion must be small, less than 60,000 km (that's about five times Earth's diameter). The planet is so close to the pulsar that, if it were any bigger, it would be ripped apart by the pulsar's gravity.
But despite its small size, the planet has slightly more mass than Jupiter.
"This high density of the planet provides a clue to its origin," said Professor Bailes.
Re: Stuff & Nonsense
« Reply #4876 on: Aug 26th, 2011, 08:38am »
Hurricane Irene targets East Coast, many evacuate, cities brace
By Jim Brumm WILMINGTON, North Carolina | Fri Aug 26, 2011 9:33am EDT
WILMINGTON, North Carolina (Reuters) - Hurricane Irene bore down on North Carolina on Friday, tens of thousands of people evacuated and East Coast cities including New York braced for a weekend hit from the powerful storm.
Fifty-five million people are potentially in Irene's path from the Carolinas to Cape Cod. Tens of thousands of coastal residents were leaving their homes for safety, starting in east North Carolina that juts into the Atlantic ocean and where Irene is due to make its first U.S. landfall on Saturday.
"This is a big, bad storm," North Carolina Governor Bev Perdue said. "We are prepared for the worst, praying for the best ... we are ready," she told CNN.
Coastal communities from the Carolinas to New England, stocked up on food and water and tried to secure homes, vehicles and boats. States, cities, ports, hospitals, oil refineries and nuclear plants activated emergency plans.
Forecasters expect that after hitting North Carolina's eastern coast as a powerful, broad hurricane on Saturday, Irene will then rake up the densely-populated U.S. eastern seaboard to New York, America's most populous city of more than eight million inhabitants, and beyond.
"Flooding, flash flooding and power outages will impact a lot of folks," Federal Emergency Management Agency Administrator Craig Fugate told CNN. The capital was also expected to feel wind and rain impact.
Extensive flight and rail service cancellations were expected.
Hurricane warnings and watches were in effect from North Carolina northwards as far as Massachusetts. Cities covered by these alerts included New York City and Boston.
EQECAT, a company that helps the insurance industry predict disaster damage, said Irene's forecast track represented "one of the worst-case scenarios" for the United States. It was one of the biggest storms to threaten the northeast in decades.
"I filled my tank up with gas in case I need to leave in a hurry or something, and get a lot of food supplies, taking everything out of my yard ... anything that can fly into a window," said Patricia Stapleton of Newport, North Carolina.
Irene weakened slightly early on Friday -- to a Category 2 hurricane from a Category 3 on the five-step Saffir-Simpson scale -- but still was packing winds of up to 110 miles per hour.
At 8 a.m. EDT, its center was about 375 miles south-southwest of Cape Hatteras, North Carolina, moving north.
NORTHEAST CITIES IN PATH
"Some re-intensification is possible today and Irene is expected to be near the threshold between Category Two and Three as it reaches the North Carolina coast," the U.S. National Hurricane Center said.
Coastal evacuations were under way in North Carolina and were ordered for beach resorts in Virginia, Delaware and Maryland. Airlines began to cut flights at eastern airports, made plans to move aircraft from the region and encouraged travelers to consider postponing trips.
"All the major metropolitan areas along the northeast are going to be impacted," National Hurricane Center Director Bill Read told Reuters Insider. "Being a large hurricane, tropical storm-force winds will extend far inland."
Virginia Governor Bob McDonnell urged residents to seek shelter by Friday night, before the winds kick up.
"Saturday is going to be a horrendous day for travel. There will be roads and bridges closed," he said.
Anticipating severe storm damage in North Carolina, U.S. President Barack Obama declared an emergency on Thursday, authorizing federal aid to support that state's response. The governors of North Carolina, Virginia, Maryland, Delaware, New Jersey, New York and Connecticut also declared emergencies.
Even if the center of Irene stays offshore as it tracks up the coast, its heavy winds and rain could lash cities like Washington, Baltimore, Philadelphia and New York and knock out power, forecasters said.
Irene will be the first hurricane to hit the U.S. mainland since Ike pounded Texas in 2008.
NEW YORK PREPARES
New York Mayor Michael Bloomberg said the city was bracing for storm conditions and flooding starting on Sunday.
He urged residents of vulnerable areas to move to safety on Friday because the mass transit system, the nation's biggest with 8 million passengers a day, may have to shut if flooding or high winds endanger its buses, subways and commuter trains.
Many New Yorkers do not have cars, so mass transit could be vital in evacuations.
Long Island, the populous area that extends about 100 miles east into the Atlantic Ocean from New York City, could be hit hard if Irene stays on its current track.
In Washington, Irene forced the postponement of Sunday's dedication ceremony for the new memorial honoring civil rights leader Martin Luther King Jr. Tens of thousands of people, including Obama, had been expected to attend.
Flooding from Irene killed at least one person in Puerto Rico and two in the Dominican Republic. The storm knocked out power in the Bahamian capital Nassau and blocked roadways with fallen trees.
(Reporting by Jane Sutton, Tom Brown, Manuel Rueda in Miami, Daniel Trotta, Joan Gralla and Ben Berkowitz in New York; Vicki Allen in Washington, Don Pessin in North Carolina; Writing by Philip Barbara and Pascal Fletcher; Editing by Sandra Maler)
Re: Stuff & Nonsense
« Reply #4878 on: Aug 26th, 2011, 11:58am »
Clever Dolphins Use Shells to Catch Fish By Brandon Keim August 25, 2011 | 2:50 pm Categories: Animals, Brains and Behavior
photo: Simon Allen, Lars Bejder/Murdoch University
Already famed as Earth’s first tool-using marine mammals, the bottlenose dolphins of Australia’s Shark Bay have proved handy yet again, by using conch shells to trap tasty fish, then shaking them into their mouths like sardines from a tin.
Unlike sponging, however, in which dolphins use sponges to find fishes hiding in mud, conching isn’t yet widespread in Shark Bay. It appears to be a relatively new innovation, pioneered by a few individuals and finally catching on.
“The extent to which the conch shell is manipulated and the rarity of the behavior suggest that ‘conching’ takes some skill and practice and might thus be another rare individual foraging tactic in Shark Bay,” wrote biologists led by the University of Zurich’s Michael Krutzen in Marine Mammal Science.
While that study came out in April, an Aug. 24 press release from Australia’s Murdoch University, home of co-authors Simon Allen and Lars Bejder, reported that conching has been observed at least six times in the last four months. That’s as often as conching was seen between the first sighting in December 1996 and the afternoon of July 31, 2007, when during a survey of western Shark Bay the researchers spotted an unfamiliar dolphin.
As they lingered nearby, hoping to dart a biopsy sample from her skin, the dolphin dived and then surfaced with her beak lodged in a conch shell, which she waved back and forth above the water. She dove again. Before she surfaced, four more dolphins arrived. When she returned with the conch, they were waiting and watching. So were the researchers.
“Photographs were taken, with two of these clearly revealing the posterior portion of a fish protruding from the conch aperture and held in the dolphin’s jaws,” they wrote in Marine Mammal Science. “The dolphin lifted the conch out of the water and manipulated it in such a manner as to drain the water and the fish from the shell.” It appeared to be an emperor fish.
Until the researchers photographed Con — sort for “Concher,” as they code-named the dolphin — the purpose of conch-wielding was unknown. From their handful of fleeting glimpses over the years, the researchers thought it likely that dolphins were simply eating conch snails inside their shells, or perhaps showing off, as do stick-wielding, clay-throwing dolphins in the Amazon.
Almost two years later, in April 2009, the researchers saw another conching dolphin, this time in a shallow, seagrass-covered spot where a wildlife observer had seen dolphins digging through seabed with shells of baler, another large marine mollusk.
Exactly how the shells are used underwater isn’t yet known. Fish might swim into them while being chased, unwittingly turning themselves into packaged snacks. The dolphins could also use the shells like nets or containers, a possibility suggested by the wildlife observer’s report of seabed-digging.
Also unknown is how conching emerged: as a variation on sponging, perhaps, or in flashes of insight from creatures whose intelligence may rival our own but happen to lack fingers and hands. Because Shark Bay’s dolphins are very territorial, however, and conching has been witnessed in disparate locations on its east and west sides, the researchers believe conching was discovered several times independently.
If, as with sponging, conching is taught primarily by females to other females, then conching was likely an invention of single mothers trying to feed their families. That it’s being witnessed with more frequency suggests Shark Bay’s dolphins are learning about it. Perhaps those four who watched Con were taking a lesson.
So far, only one male dolphin, the individual spotted in 2009, has been seen conching. While his name among dolphins is unknown, the researchers dubbed him Wim, short for William the Concherer.
Re: Stuff & Nonsense
« Reply #4881 on: Aug 26th, 2011, 12:24pm »
Earth-Bound Asteroids Come from Stony Asteroids, New Studies Confirm ScienceDaily (Aug. 26, 2011)
Researchers got their first up-close look at dust from the surface of a small, stony asteroid after the Hayabusa spacecraft scooped some up and brought it back to Earth. Analysis of these dust particles, detailed in a special issue of the journal Science this week, confirms a long-standing suspicion: that the most common meteorites found here on Earth, known as ordinary chondrites, are born from these stony, or S-type, asteroids. And since chondrites are among the most primitive objects in the solar system, the discovery also means that these asteroids have been recording a long and rich history of early solar system events.
This is a Hayabusa capsule landed at Woomera in South Australia. (Credit: Image copyright JAXA/ISIS)
The 26 August issue of Science includes six reports and a Perspective article that highlight the initial studies of this asteroid dust.
The Hayabusa spacecraft was launched by the Japan Aerospace Exploration Agency (JAXA) in 2003 to sample the surface of the near-Earth asteroid known as 25143 Itokawa. The unmanned vessel reached its destination a little more than two years later -- and in November 2005, it made two separate touchdowns on the surface of Itokawa. Although its primary sampler malfunctioned, the spacecraft was able to strike the asteroid's surface with an elastic sampling horn and catch the small amount of dust particles that were kicked up. After reentering Earth's atmosphere and landing in South Australia in June 2010, Hayabusa's delicate samples were analyzed extensively by various teams of researchers.
"Science is very excited and pleased to be presenting these important scientific analyses," said Brooks Hanson, Deputy Editor of the Physical Sciences. "The first samples that researchers collected beyond Earth were from the moon, and the first analyses of those samples were also published in Science. Those samples, along with the more recent sampling of a comet and the solar wind, have changed our understanding of the solar system and Earth. They are still yielding important results. These Hayabusa samples are the first samples of an asteroid. Not only do they provide important information about the history of the asteroid Itokawa, but by providing the needed ground truth that is only possible through direct sampling, they also help make other important samples -- like meteorite collections and the lunar samples -- even more useful."
The asteroid sampled by Hayabusa is a rocky, S-type asteroid with the appearance of a rubble pile. Based on observations from the ground, researchers have believed that similar S-type asteroids, generally located in our solar system's inner and middle asteroid belt, are responsible for most of the small meteorites that regularly strike Earth. But, the visible spectra of these asteroids have never precisely matched those of ordinary chondrites -- a fact that has left researchers suspicious of their actual affiliation. The only way to confirm a direct relationship between meteorites and these S-type asteroids was to physically sample the regolith from an asteroid's surface.
Tomoki Nakamura from Tohoku University in Sendai, Japan and colleagues from across the country and in the United States were among the first to analyze this regolith brought back by Hayabusa. The team of researchers used a combination of powerful electron microscopes and X-ray diffraction techniques to study the mineral chemistry of Itokawa's dust particles.
"Our study demonstrates that the rocky particles recovered from the S-type asteroid are identical to ordinary chondrites, which proves that asteroids are indeed very primitive solar system bodies," said Nakamura.
The researchers also noticed that Itokawa's regolith has gone through significant heating and impact shocks. Based on its size, they conclude that the asteroid is actually made up of small fragments of a much bigger asteroid.
"The particles recovered from the asteroid have experienced long-term heating at about 800 degrees Celsius," said Nakamura. "But, to reach 800 degrees, an asteroid would need to be about 12.4 miles (20 kilometers) in diameter. The current size of Itokawa is much smaller than that so it must have first formed as a larger body, then been broken by an impact event and reassembled in its current form."
Separate teams of researchers, including Mitsuru Ebihara from Tokyo Metropolitan University and colleagues from the United States and Australia, cut open the tiny regolith grains returned by Hayabusa to get a look at the minerals inside them. Their composition shows that the dust grains have preserved a record of primitive elements from the early solar system. Now, those mineral compositions can be compared to tens of thousands of meteorites that have fallen to Earth, and then correlated to the visible spectra of other asteroids in space.
Akira Tsuchiyama from Osaka University in Toyonaka, Japan and colleagues from around the world also analyzed the three-dimensional structures of the dust particles. Since dust from the surface of the moon is the only other type of extraterrestrial regolith that researchers have been able to sample directly (from the Apollo and Luna missions), these researchers closely compared the two types.
"The cool thing about this Itokawa analysis is the tremendous amount of data we can get from such a small sample," said Michael Zolensky from the NASA Johnson Space Center in Houston, Texas, a co-author of the research. "When researchers analyzed regolith from the moon, they needed kilogram-sized samples. But, for the past 40 years, experts have been developing technologies to analyze extremely small samples. Now, we've gained all this information about Itokawa with only a few nano-grams of dust from the asteroid."
According to the researchers, Itokawa's regolith has been shaped by erosion and surface impacts on the asteroid, whereas lunar regolith, which has spent more time exposed to solar winds and space weathering, has been more chemically altered.
Takaaki Noguchi from Ibaraki University in Mito, Japan, and colleagues cite this chemical difference between the lunar dust and the Itokawa samples as one of the reasons astronomers have never been able to definitively tie ordinary chondrites to S-type asteroids in the past.
"Space weathering is the interaction between the surface of airless bodies, like asteroids and the moon, and the energetic particles in space," said Noguchi. "When these energetic particles -- like solar wind, plasma ejected from the Sun and fast-traveling micrometeoroids -- strike an object, pieces of them condense on the surface of that object. In the vacuum of space, such deposits can create small iron particles that greatly affect the visible spectra of these celestial bodies when they are viewed from Earth."
But now, instead of using lunar samples to estimate the space weathering on an asteroid in the future, researchers can turn to the asteroid regolith for direct insight into such processes.
Two more international studies led by Keisuke Nagao from the University of Tokyo and Hisayoshi Yurimoto from Hokkaido University in Sapporo, Japan, respectively, have determined how long the regolith material has been on the surface of Itokawa and established a direct link between the oxygen isotopes in ordinary chondrites and their parent, S-type asteroids.
According to the researchers, the dust from Itokawa has been on the surface of the asteroid for less than eight million years. They suggest that regolith material from such small asteroids might escape easily into space to become meteorites, traveling toward Earth.
"This dust from the surface of the Itokawa asteroid will become a sort of Rosetta Stone for astronomers to use," according to Zolensky. "Now that we understand the bulk mineral and chemical composition of the Hayabusa sample, we can compare them to meteorites that have struck the Earth and try to determine which asteroids the chondrites came from."
The report by Nakamura et al. received additional support from NASA grants.
The report by Yurimoto et al. received additional support from a Monka-sho grant and the NASA Muses-CN/Hayabusa Program.
The report by Ebihara et al. received additional support from a grant-in-aid defrayed by the Ministry of Education, Culture, Science and Technology of Japan and a grant from NASA.
The report by Noguchi et al. received additional support from the NASA Muses-CN/Hayabusa Program.
The report by Tsuchiyama et al. received additional support from a grant-in-aid of the Japan Ministry of Education, Culture, Sports, Science and Technology and the NASA Muses-CN/Hayabusa Program.
Re: Stuff & Nonsense
« Reply #4886 on: Aug 27th, 2011, 08:19am »
Irene brings its fury to North Carolina
The hurricane's top sustained winds are 85 mph as it begins its churn up the East Coast, and thousands have already lost power. Authorities beg people to get out of harm's way.
From the Associated Press 5:10 AM PDT, August 27, 2011 MOREHEAD CITY, North Carolina
Hurricane-force winds and drenching rains from Irene battered the North Carolina coast early Saturday as the storm began its potentially catastrophic run up the Eastern Seaboard. More than 2 million people were told to move to safer places, and New York City ordered the nation's biggest subway system shut down for the first time because of a natural disaster.
The National Hurricane Center in Miami said Irene's maximum sustained winds were around 85 mph on Saturday morning, down from about 100 mph a day earlier. But they warned the hurricane would remain a large and powerful one throughout the day as it trekked toward the mid-Atlantic.
"The hazards are still the same," NHC hurricane specialist Mike Brennan said. "The emphasis for this storm is on its size and duration, not necessarily how strong the strongest winds are."
Hurricane-force winds first arrived near Jacksonville, N.C., around 6:15 a.m. A little more than an hour later, the storm's center passed near the southern tip of North Carolina's Outer Banks. The eye of the storm is typically calm, but the storm's wind and rain are far from over. Forecasters said the landfall has little significance, as Irene remains a dangerous storm.
Just after daybreak in Nags Head on the Outer Banks, about 200 miles northeast of Jacksonville, winds whipped heavy rain across the resort town. Tall waves covered what had been the beach, and the surf pushed as high as the backs of some of the houses and hotels fronting the strand. Lights flickered in one hotel, but the power was still on.
As the storm's outer bands of wind and rain lashed the North Carolina coast, knocking out power in places, authorities farther north begged people to get out of harm's way. Officials in the northeast, not used to tropical weather, feared it could wreak devastation.
"Don't wait. Don't delay," said President Barack Obama, who decided to cut short his summer vacation by a day and return to Washington. "I cannot stress this highly enough: If you are in the projected path of this hurricane, you have to take precautions now."
The storm's center was about 5 miles north of Cape Lookout on North Carolina's Outer Banks early Saturday and lumbering north-northeastward at 14 mph.
Wind and rain knocked out power to more than 91,000 customers along the North Carolina coast, including a hospital in Morehead City. A woman who answered the phone there said the hospital was running on generators.
Power was still on in Buxton on Hatteras Island, part of the Outer Banks and home to real estate agent Danny Couch. He had lost a piece of gutter and leaves were blowing around, but he saw no trees down.
"We'll wait and see what happens in the next couple of hours, but right now, it's what we're used to," he said about two hours before sunrise Saturday.
A coastal town official in North Carolina said witnesses believed a tornado spawned by Irene lifted the roof off the warehouse of a car dealership in Belhaven on Friday night and damaged a mobile home, an outbuilding and trees.
Forecasters said the core of Irene would roll up the mid-Atlantic coast Saturday night and over southern New England on Sunday.
Hurricane warnings were issued from North Carolina to New York and farther north to the islands of Nantucket and Martha's Vineyard off Massachusetts. Evacuation orders covered at least 2.3 million people, including 1 million in New Jersey, 315,000 in Maryland, 300,000 in North Carolina, 200,000 in Virginia and 100,000 in Delaware.
"This is probably the largest number of people that have been threatened by a single hurricane in the United States," said Jay Baker, a geography professor at Florida State University.
U.S. airlines canceled at least 6,100 flights through Monday, grounding hundreds of thousands of passengers as the storm could strike major airports from Washington to Boston.
New York City ordered more than 300,000 people who live in flood-prone areas to leave, including Battery Park City at the southern tip of Manhattan, Coney Island and the beachfront Rockaways. But it was not clear how many would do it, how they would get out or where they would go. Most New Yorkers don't have a car.
The city said it would shut down the subways and buses at noon Saturday, only a few hours after the first rain is expected to fall. The transit system carries about 5 million people on an average weekday, fewer on weekends. It has been shut down several times before, including during a transit workers' strike in 2005 and after the Sept. 11 attacks a decade ago, but never for weather.
Aviation officials said they would close the five main New York City-area airports to arriving domestic and international flights beginning at noon on Saturday. Many departures also were canceled.
The airports are John F. Kennedy International, Newark Liberty International, LaGuardia, Stewart International and Teterboro.
Mayor Michael Bloomberg said there was little authorities could do to force people to leave and warned: "But if you don't follow this, people may die."
Shelters were opening Friday afternoon, and the city was placed under its first hurricane warning since 1985.
Transit systems in New Jersey and Philadelphia also announced plans to shut down, and Washington declared a state of emergency.
Some hardy holdouts in North Carolina put plywood on windows, gathered last-minute supplies and tied down boats. More than half the people who live on two remote islands, Hatteras and Ocracoke, had ignored orders to leave, and as time to change their minds ran short, officials ordered dozens of body bags. The last ferry from Ocracoke left at 4 p.m. Friday.
"I anticipate we're going to have people floating on the streets, and I don't want to leave them lying there," said Richard Marlin, fire chief for one of the seven villages on Hatteras. "The Coast Guard will either be pulling people off their roofs like in Katrina or we'll be scraping them out of their yards."
Some took to shelters for protection.
Susan Kinchen, her daughter and 5-month-old granddaughter came to West Carteret High School with about 50 others. She said they didn't feel safe in their trailer, and the Louisiana native was reminded of how her old trailer lost its roof to Hurricane Katrina, almost six years ago to the day, on Aug. 29, 2005.
"We live in a trailer with her," said Kinchen, referring to the infant. "I'm not taking any chances."
After the Outer Banks, the next target for Irene was the Hampton Roads region of southeast Virginia, a jagged network of inlets and rivers that floods easily. Emergency officials have said the region is more threatened by storm surge, the high waves that accompany a storm, than wind. Gas stations there were low on fuel Friday, and grocery stores scrambled to keep water and bread on the shelves.
In Delaware, Gov. Jack Markell ordered an evacuation of coastal areas on the peninsula the state shares with Maryland and Virginia.
Kenneth Roe was filling up three 5-gallon gas cans at an Exxon station in Salisbury, Md., on Friday night. A manager at a Home Depot in Lewes, Del., the 34-year-old had worked 18 hours straight on Thursday and another five hours on Friday, his day off. He said the store was staying open 24 hours in order to provide supplies and that generators in particular were in high demand. Approximately 50 generators put out at 6 a.m. were gone by 8 a.m., he said, even though each cost $600.
"We're going to get something no matter what," he said of the effects of the storm.
In Baltimore's Fells Point neighborhood, one of the city's oldest waterfront neighborhoods, people filled sandbags and placed them at the entrances to buildings. A few miles away at the Port of Baltimore, vehicles and cranes continued to unload huge cargo ships that were rushing to offload and get away from the storm.
And in Atlantic City, N.J., all 11 casinos announced plans to shut down Friday, only the third time that has happened in the 33-year history of legalized gambling in that state.
"I like gambling, but you don't play with this," Pearson Callender said as he waited for a Greyhound bus out of town. "People are saying this is an act of God. I just need to get home to be with my family."