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August 16, 2014

US researchers find a large asteroid held together by forces other than gravity

US researchers find a large asteroid held together by forces other than gravity

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Saturday, August 16, 2014

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Asteroid 1950 DA, Arecibo Observatory radar image

A team of researchers from the University of Tennessee, Knoxville, has confirmed that near-Earth asteroid (29075) 1950 DA is primarily held together by van der Waals forces rather than gravity. They have shown that the rotation rate of the 1.1 km asteroid is higher than could be possible if only gravity and friction were responsible for holding it together. Cohesive forces prevent large scale shedding of material and breakup of the asteroid. Their study was published Wednesday in Nature.

The researchers found that the bulk density 1.7±0.7 g/cm³ of the asteroid is approximately two times lower than the value required for self-gravity to balance out the centrifugal forces caused by rotation. As Ben Rozitis, a planetary scientist and a co-author of the study, told Space.com: “I was expecting to find a high-density metallic asteroid, as such an asteroid wouldn’t require cohesive forces to hold itself together under its fast rotation. Instead we found the opposite! […] We knew from previous work that this asteroid was rotating faster than it should be, and we wanted to know why”.

Spectral observations of 1950DA indicated that it is either an E- or M-type asteroid in the Tholen classification. However, its low optical albedo and low radar circular polarization ratio (a very smooth surface at centimetre to decimetre scales) showed that it cannot be an E-type asteroid.

Unusually for an M-type asteroid (which are mostly metallic), 1950DA has low radar albedo. It would have been puzzling, if it was not for the Rosetta observations of 21 Lutetia, which is also an M-type asteroid with very similar low radar albedo. Researchers have used for 1950DA the same meteorite analogue which was earlier found to fit best 21 Lutetia: enstatite chondrite with grain density of 3.55 g/cm³. It allowed to calculate macro-porosity of 51±19%, indicating that 1950DA is a rubble-pile asteroid.

Taking into account thermal-infrared measurements of thermal inertia, presence of a fine-grained regolith is implied, primarily around 1950DA’s equator. Negative ambient gravity near the equator of the asteroid (48±24% of its surface) requires existence of cohesive forces to prevent loss of material. This is similar to an effect noticed between the fine grains of regolith on the Moon. Lunar regolith was found to be highly cohesive because of van der Waals forces between grains by the Apollo 17 expedition in 1974.

As Ben Rozitis explained: “We found a low-density rubble pile that traditionally would be unable to hold itself together unless cohesive forces were present. It’s exciting because we’ve provided the first evidence that cohesive forces are important for small asteroids, which had only been predicted up until now.”

The balance between cohesion and negative gravity requires small grain sizes consistent with the grain size distribution on 1950DA, and similar to that of another rubble-pile asteroid, (25143) Itokawa. Unlike Itokawa, 1950DA does not have large boulders on the surface; they may have been lost as 1950DA’s rotation accelerated due to YORP effect. This effect results in a change of the rotation rate of an asteroid (either faster or slower), and is caused when the Sun heats up an object unevenly, due to asymmetric surface topography. As the heat escapes, the rotation rate is slowly changed due to an uneven rate of cooling. The researchers find that a rubble-pile asteroid may have a high rotation rate, if it is held together by cohesive forces between the grains. But as the spin rate increases due to YORP effect, the centrifugal force may cause the rubble pile to eventually separate as it happened with P/2013 R3.

The findings may have implications for asteroid impact avoidance. A very small impulse may break one potentially hazardous object into several pieces. As Ben Rozitis said: “You’d want to avoid interacting with the asteroid directly. An alternative is to use a ‘gravity tractor,’ or a heavy spacecraft placed near the asteroid, which uses the force of gravity to pull the asteroid off course”. Bong Wie, an aerospace engineer at Iowa State University in Ames, noted: “I just hope that an asteroid on a collision course with Earth will not be spinning rapidly and it will not be a rubble-pile asteroid”.

According to Daniel Scheeres, an aerospace engineer at the University of Colorado, Boulder, understanding such cohesive forces may also be important for future asteroid mining. Ben Rozitis clarified: “Mining missions intend to visit small asteroids about 10 meters (33 feet) or less in size, as it is thought that they are predominantly solid bodies. However, cohesive forces enable such small asteroids to be rubble piles instead. A small rubble-pile asteroid would be harder to interact with and collect, as it can easily deform or break up when subject to external forces.”

The study was supported by Jet Propulsion Laboratory, California Institute of Technology and the NASA.



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March 5, 2012

Deadly tornadoes blast U.S. Midwest leaving 39 dead

Deadly tornadoes blast U.S. Midwest leaving 39 dead

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Monday, March 5, 2012

Disasters and accidents

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At least 39 people are confirmed dead, dozens injured and numerous buildings are left damaged in several states after series of tornadoes hit the U.S. Midwest March 2. The storm system stretched from the Gulf Coast to the Great Lakes. Southern Indiana, northern Alabama and parts of Kentucky and Tennessee were affected the most.

Images from the GOES 13 satellite shows the formation and movement of the storm system.
Image: National Oceanic and Atmospheric Administration.

The first warning went out around 9:30 a.m. Eastern Standard Time and by about 1:30 p.m. Eastern Standard Time, at least twelve tornadoes had touched down in three different states. At least fourteen people were confirmed dead in Indiana. Officials are still trying to determine how many people might have died and assessing the damage.

New Pekin, Indiana, Marysville and Henryville are reported to have been hit the worst. Marysville about a hour north of Louisville, Kentucky has been reported to be nearly flatted. In Kentucky, at least 17 people had died and at least 200 injuries have been reported. Only one has been confirmed dead in Alabama but at least eleven people were injured during the storm. There are three confirmed dead in Clermont County, Ohio.

Damage reports in the Midwest and South keep piling up. Golf ball, tennis ball and softball size hail was reported in several states. Severe damage was reported in Nashville, Tennessee and Knoxville after high winds and 3 inch in diameter hail tore through the cities.

At the Limestone Correctional Facility in northern Alabama roofs were ripped off two dormitories housing over 500 inmates and multiple security fences were knocked down. Even though the prison lost power, nobody was injured or escaped. Also, flights were delayed for over an hour after storm debris littered the runways at the Cincinnati/Northern Kentucky International Airport.

The National Weather Service issued 255 tornado warnings on Friday, received 94 reports of tornadoes, 208 reports of strong winds and 410 reports of hail. The storms, caused by a warm, moist and unseasonable air mass that then mixed with colder air, followed a series of tornadoes earlier in the week that killed 13 people in Kansas, Missouri, Illinois and Tennessee.

The storms have raised fear that 2012 will be another bad year for tornadoes. Last year was the deadliest year in a century due to tornadoes, killing 550 people.



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December 30, 2010

US pool player Wade Crane dies in car accident age 66

US pool player Wade Crane dies in car accident age 66

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Thursday, December 30, 2010

Wade Crane in 2003
Image: RailbirdJAM2.

US professional pool player Wade Crane has died after a one-car accident in Tennessee, USA. He was 66 years old. Crane’s Volkswagen crossed three lanes of traffic into the concrete retaining wall, then bounced back across five more lanes of traffic into another retaining wall.

It is believed that Crane suffered from an undiagnosed medical condition. News of the crash was broken by The Knoxville News Sentinel.

Crane was a former world champion of both 9-ball and 8-ball pool. A self-taught player, for 21 years he was the only person in pool history to shoot a perfect score in the finals of a major tournament.

Fellow pool players including Nick Varner, Johnny Archer, and Shannon Daulton paid tribute to Crane.



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August 10, 2010

Actress Patricia Neal dies aged 84

Actress Patricia Neal dies aged 84 – Wikinews, the free news source

Actress Patricia Neal dies aged 84

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Tuesday, August 10, 2010

Obituaries
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Actress Patricia Neal.
Image: David Shankbone.

Patricia Neal, an Academy Award-winning actress, died at 84 of lung cancer at her home in Edgartown, Massachusetts, United States in the presence of her family. “She faced her final illness as she had all of the many trials she endured: with indomitable grace, good humor and a great deal of her self-described stubbornness,” said her family.

Neal won an Academy Award, or Oscar, for her portrayal of a middle aged housekeeper in the 1963 film Hud. In 1965, she suffered a series of strokes but later returned to acting, earning an Oscar nomination for her performance in The Subject Was Roses and three Emmy nominations.

Her filmography includes The Fountainhead (1949), The Day the Earth Stood Still (1951) and A Face in the Crowd (1957). She also played the role of Olivia Walton in The Homecoming: A Christmas Story (1971).

She married Roald Dahl in 1953 and they had five children, of whom one died of measles at the age of 7. They divorced in 1983 when she came to know of his affair with her best friend.

“Frequently my life has been likened to a Greek tragedy, and the actress in me cannot deny that comparison,” she said in her 1988 biography, As I Am.

The Patricia Neal Rehabilitation Centre in Knoxville, Tennessee, U.S.A is named after the actress and looks after people suffering from strokes and spinal cord and brain injuries. Knoxville is also the place where she grew up.



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July 29, 2010

Tennessee Lieutenant Governor suggests that Islam is a \’cult\’

Tennessee Lieutenant Governor suggests that Islam is a ‘cult’

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Thursday, July 29, 2010

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While answering a question regarding a proposed mosque in a Tennessee town, that state’s Lieutenant Governor, Ron Ramsey, questioned if Islam is a cult.
Image: Paul Cruickshank.
(Image missing from commons: image; log)

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A Tennessee politician has been criticised by Islamic groups and Islamic leaders by suggesting that Islam is a cult and is therefore ineligible for protection under the first amendment of the United States constitution, which guarantees freedom of religion.

Though Tennessee Lieutenant Governor Ron Ramsey, at a campaign stop in Chattanooga earlier in the month, said he’s “all about freedom of religion”, he also said that “[y]ou could even argue whether that being a Muslim is actually a religion, or is it a nationality, way of life, cult or whatever you want to call it”.

Lt. Gov. Ramsey had been asked about a proposed Islamic mosque and community centre that has been slated for construction in the town of Murfreesboro, Tennessee, and also about the “threat that is invading our country from Muslims”.

Ramsey’s comments have been scrutinized by groups all over the country, while Ramsey’s rivals for the lieutenant governor position tried to avoid the controversy.

Ibrahim Hooper, national communications director of the Council on American-Islamic Relations, called Ramsey’s remarks “part of an unfortunate trend in our society” and part of “a disturbing trend in our nation in which it is suggested that American Muslims should have fewer or more restricted constitutional rights than citizens of other faiths.” Hooper also encouraged Ramsey to find people “who can offer him balanced and accurate information about Islam.”

Ramsey’s Republican rivals, U.S. Representative Zach Wamp and Knoxville Mayor Bill Haslam, both tried to avoid the controversy about the cult comments. According to campaign spokesman Sam Edelen, Wamp declined to comment as he was “busy with voting”. Meanwhile Bill Haslam’s campaign spokesman Dave Smith stated in an e-mail that “The mayor’s faith is very important to him, and he respects the right of others to practice their faith, so long as they are respectful of the communities in which they live and the laws of the land.”

Later, Ramsey clarified his position by stating that he has “no problem — and I don’t think anyone in this country has a problem — with peace-loving, freedom-loving Muslims that move to this country and assimilate into our society.” However, Ramsey said he’s concerned that “far too much of Islam has come to resemble a violent political philosophy more than peace-loving religion. It’s time for American Muslims who love this country to publicly renounce violent jihadism and to drum those who seek to do America harm out of their faith community.”

According to the Council on American-Islamic Relations, there are 1.2 billion Muslims in the world and 7 million in the United States. The U.S. Religious Landscape Survey by the Pew Forum on Religion & Public Life has stated that there are 63,000 Muslims in Tennessee, or 1% of that state’s population.



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August 21, 2008

Shooting at school leaves one dead in Tennessee, United States

Shooting at school leaves one dead in Tennessee, United States

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Thursday, August 21, 2008

Crime and law
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On Thursday, 15-year-old student, Ryan McDonald, was shot and killed. The shooting occurred at just after 8:00am (UTC-5), at Central High School, in Knoxville, Tennessee.

Map of Tennessee, showing where Knoxville is.

According to Deputy Chief of Police of the Knoxville police department, William C. Roehl stated that the shooting was not “random” and that “they had contact with one another”. The shooting which occurred 8:11am (UTC-5), followed a confrontation in the cafeteria. Police arrived on the scene at 8:13am, and the suspect was taken into custody at 8:17am. McDonald was taken to the University of Tennessee Medical Center where he died at 8:57am, according to the police.

Police have arrested Jamar B. Siler, also 15, and charged him with first-degree murder. Judge Tim Irwin set September 17, 2008 as the trial date. Siler is being held at a juvenile detention center.

Kevin Perry, a pastor at Word of Life Ministries, said he had spoken to a student who witnessed the shooting.

“He saw them when they were arguing and pushing and shoving,” Perry said, recounting what the student had told him. “He didn’t see the guy shoot him. What he did see was the guy fall.”

Another high school student, Chad Griffin, was ten feet away from where the confrontation occurred and said that “he [McDonald] got shot and started walking and he was holding his chest. There was blood everywhere. And then he fell and his arm hit me.”

The school was preparing to release students, and bring them to a local church were they could be picked up by their guardians. Central High School has around 1,400 students.



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September 4, 2005

Former US VP Al Gore spearheads transport of hurricane victims to relief in home state

Former US VP Al Gore spearheads transport of hurricane victims to relief in home state

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Sunday, September 4, 2005

Knoxville, Tennessee — About 140 mostly weak or ailing victims of the hurricane ravaged city of New Orleans were flown here Saturday by a volunteer crew on a flight chartered by former United States Vice President Albert Gore.

The victims were greeted by Knoxville’s mayor, many medical professionals, and other volunteers helping them board buses destined to area hospitals. There they were to be assessed and sent to a local Red Cross shelter.

Although Gore was present on the flight and assisted moving the passengers to the waiting buses, he “declined to take credit for the airlift, fearing it would be ‘politicized.'”[1] An associate of Gore who assisted in the project, Dr. Anderson Spickard, said that although Gore chartered the flight, “we’ll decide who pays for it later.”

Spickard also remarked that originally the plane was to take two flights that day, but flight delays forestalled that plan. The plane will leave Knoxville Saturday evening, he said, to make another aid flight on Sunday.

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March 30, 2005

Woman sells name on eBay

Woman sells name on eBay – Wikinews, the free news source

Woman sells name on eBay

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Wednesday, March 30, 2005

A Knoxville, USA woman has sold her name on eBay and received an offer. Terri Iligan, age 33, will legally be named “goldenpalace.com” after the required legal work is complete.

The casino owning the website paid $15,199 over the eBay auction service.

She said that she got the idea when trying to find how much it would cost to send one of her children to a golf school previously attended by Tiger Woods.

In an interview by Knoxville TV station WATE, she said, “To my kids and to my husband, I will always be Terri.” As to the opinion of her husband and children, she said, “He thinks it’s funny. As long as they get to call me mom, they don’t care.”


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