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Asteroids reveal solar system’s tumultuous past

The widely accepted history of the asteroid belt between the orbits of Mars and Jupiter is that the myriad objects are the remnants of a planet that began but failed to coalesce during the formation of the solar system. The millions of the objects in the belt failed to come together due to the massive disruption caused by Jupiter’s gravity. The compositions of the asteroids in the belt vary depending on the distance from the Sun.

However, according to a press release, a new study by Francesca DeMeo of the Harvard-Smithsonian Center for Astrophysics and Benoit Carry of Paris Observatory challenges that view. DeMeo and Carry poured over data from the Sloan Digital Sky Survey, a cosmological mapping project undertaken by around 150 scientists at institutions around the world. DeMeo and Carry focused on the compositions of thousands of objects in the asteroid belt. Their study revealed that the compositions of the asteroids, especially the smaller objects, are far more diverse than previously thought.

DeMeo and Carry’s findings suggest that, as the solar system was forming, the gas giants, such as Jupiter, careened inward towards the Sun and back out to where they now reside. The movement of Jupiter could have deprived the original asteroid belt of all but a tenth of one percent of its population, as the massive planet moved as close to the Sun as Mars is today. However, as the giant planets continued to migrate through the early solar system, they redirected objects from as near the Sun as Mercury and as distant as Neptune, forming the asteroid belt as we know it.

“The asteroid belt is a melting pot of objects arriving from diverse locations and backgrounds,” said DeMeo.

The new findings align with the idea that asteroid impacts brought most of Earth’s water early the planet’s evolution. The disruptions caused by the movements of the giant planets could have propelled those important asteroids towards Earth. However, this raises the troubling possibility that Earth-like exoplanets might also need an asteroid bombardment to deliver water; if similar disturbances caused by gas giants did not occur in many other solar systems, then habitable Earth-like exoplanets could be scarcer than surveys, such as Kepler, would suggest.

The new research has been published in the January 30 issue of the journal Nature.

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Atlanta lawmakers caught without a plan for snow storm

What a nightmare. People were stuck for up to 6 hours in traffic. There reportedly were as many as a thousand accidents. Folks had to leave their cars on icy roadways and walk long distances in freezing weather. Others had to find shelter at Home Depot stores.

Georgia Gov. Nathan Deal tried to shift blame for the awful fiasco to weather forecasters.

“The National Service continually had their modeling showing that the city of Atlanta would not be the primary area where the storm would hit, that it would be south of Atlanta, ” Deal said Wednesday (Jan. 29).

But according to CNN meteorologist Chad Meyers, Atlanta had plenty of warning. Meyers himself predicted that up to 2 inches of snow would fall during the early afternoon. As it happened, the city received 2.3 inches.

Atlanta’s mayor, Kasim Reed, said schools and local businesses were partly to blame because they let students and workers leave at the same time, instead of staggering their exits, according to CNN.

“I said immediately yesterday that releasing all of these folks was not the right way to go,” Reed told CNN’s Carol Costello Wednesday. “If I had my druthers, we would have staggered the closures.”

Despite the hours of misery endured by thousands of people trying to navigate a unprepared city that was essentially paralyzed by the storm, Reed praised the city’s response.

“We got a million people out of the city,” Reed said. “We have not had any fatalities. We cleared the way of all of our hospitals, all of our police stations.”

At the start of a rather testy exchange, Costello pointed out that Atlanta escaped having any fatalities only “by the grace of God,” saying there were a thousand traffic accidents and that people had to abandon their cars to walk home “in frigid conditions.”

And according to Atlanta-based CNN, a great many of those million people Reed said got out of the city spent the night “sleeping in their cars, on the side of the road, or in gas station parking lots.”

Former Lt. Gen. Russell Honore, who played an important role in coordinating relief efforts after Hurricane Katrina, placed the blame squarely on officials’ lack of preparedness.

“They need to have in Atlanta the same type of government you have in New York City, where the mayor controls the city and everything around that city, and the mayor can make decisions on road closures; he has emergency powers as when schools close,” Honore said in a CNN report, adding that the snowstorm mess happened because of “a failure to lead.”

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Astronomers discover supernova visible to the naked eye

Sometimes, the greatest scientific discoveries are not intentional. At 7:20 p.m. GMT on January 21, a group of students at the University of London Observatory trained their telescope on a bright galaxy known as Messier 82 or the Cigar Galaxy. According to a University College London press release, the supervisor, Dr. Steve Fossey, had planned to demonstrate to the students, Ben Cooke, Tony Brown, Matthew Wilde, and Guy Pollack, how to use a special camera on the telescope. Instead, while fine-tuning the telescope’s orientation, Fossey spied an unrecognized star-like body superimposed over M82.

Fossey and the students quickly compared what they were seeing to archive images of M82, which revealed that the radiant object was new. With clouds rolling in over London, Fossey and the students activated a second telescope to rule out the possibility that the object was an instrumental artifact. They also initiated a series of 1 and 2-minute exposures using different color filters to see if the object persisted and to ascertain its color and brightness. By 7:40, clouds made continued observation impossible, but the object was present in both of Fossey’s data sets, indicating that it is a real astronomical body.

The new star did not appear in previous observations of M82, suggesting an ephemeral object, such as a supernova. In short order, Fossey notified the International Astronomical Union’s Central Bureau for Astronomical Telegrams, which catalogues supernovae. He also sent the data to a supernova research team in the United States; this team has access to spectroscopic equipment.

The spectra obtained by astronomers around the globe indicate that the object in M82 is a Type 1a supernova. Such an object forms when a white dwarf star siphons matter off of a bigger nearby star until it becomes unstable and explodes. The Union’s official findings have yet to be released, so the supernova remains nameless for now.

The new supernova in M82 is about 12 million light-years from Earth, approximately the same distance as a supernova found in 1993 in galaxy M81. These are still much farther away than the closest supernova observed since the invention of the telescope; this is Supernova 1987A, which was discovered in February 1987 and is 168,000 light-years away.

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ESA probe discovers water on Ceres asteroid

Ceres is a remarkable object. According to NASA, it is the largest object in the asteroid belt between Mars and Jupiter, with a diameter of about 590 miles (950 kilometers). Unlike most of the objects in the asteroid belt, Ceres is spherical, and is categorized as a dwarf planet. Only gravitational disturbances caused by Jupiter during the formation of the planets prevented Ceres becoming a fully-fledged planet. Ceres is composed of a rocky core, a mantle of water ice, and a thin outer crust. Now, a European Space Agency mission has found the first signs of water vapor around Ceres, a first for any asteroid belt object.

According to an ESA press release, a team led by Michael Küppers of ESA’s European Space Astronomy Centre in Spain has used the HIFI instrument on the Herschel space observatory to detect water vapor around Ceres. Herschel orbits the Sun 1.5 million kilometers from Earth, at the gravitationally stable second Lagrange point.

All the water vapor is coming from only two sites on the surface; the researchers studied variations in the water signal during Ceres’ 9-hour rotation to determine the number and location of the water sources. Approximately 6 kilograms of water vapor is being released every second, indicating that only a small fraction of Ceres’ surface harbors water ice.

The most likely explanation is that the water vapor is being generated via sublimation, in which ice is heated and changes directly into gas, rather than liquid water. On Ceres, the outgassing of water vapor takes surface dust with it, exposing fresh ice beneath to become heated and maintain the sublimation rate. A similar process occurs on comets. Both of the areas emitting water vapor are 5 percent darker than the average surface conditions on Ceres. This means they absorb more sunlight and are therefore the warmest areas on the surface, promoting a more efficient sublimation environment.

It is also possible that geysers or cryovolcanism is responsible for the haze of water vapor around Ceres. This and other questions will be examined by NASA’s Dawn spacecraft, which is due to arrive at Ceres in early 2015 and will provide detailed surface maps and observations of how the water vapor activity fluctuates.

Understanding the nature of water on Ceres is crucial to understanding how water traveled throughout the early solar system. When the solar system formed 4.6 billion years ago, its innermost regions were too hot for water to condense on Mercury, Venus, Earth, and Mars. Water was likely delivered to these primordial worlds by asteroids and comets during a sustained bombardment about 3.9 billion years ago.

The new discovery was published in the January 22 issue of the journal Nature.

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U.S., Japan at odds over dolphin hunts

The United States and Japan have been staunch allies for 60 years, but disagree over Japan’s annual slaughter of dolphins in a small cove in a Japanese town. While Japanese defenders of the practice say it’s a cultural ritual,  many Americans say it’s brutal murder.

American conservation activists have long been critics of the hunt for dolphins in the small Japanese town of  Taiji. Every year, fishermen attack dolphins with knives after driving them to a small cove.  After the dolphins are captured, they are either sold to international aquariums or killed for eating.

Japanese supporters of the practice, including government spokesperson Yoshihide Suga, say that dolphin hunts are a centuries-old tradition. Defenders also say that dolphin is a rare delicacy in the country, and hunting them keeps them from eating too many fish and disrupting Japan’s marine ecosystem. Tajii’s mayor defiantly said that “We are not going to change our plans for the town based on the criticism of foreigners”.

Dolphin hunts are big business in Japan, with sales of the animals to aquariums drawing large sums of money. Tajii has plans to build a marine park of its own. Plans are underway to have the park filled with dolphins on display as the main attractions and offered as the main course for tourists, too.

Critics of the dolphin hunts include many high-profile celebrities and dignitaries. The U.S. ambassador to Japan, Caroline Kennedy, tweeted that she is “deeply concerned by inhumaneness of drive hunt dolphin killing. ”   Guns ‘n’ Roses drummer Matt Sorum also took to social media to express his disapproval of the dolphin hunt, saying Japanese fishermen care more about ” greed not tradition.

In addition to Kennedy and Sorum, animal rights and conservationist groups have been campaigning to stop the hunts for years. Many activists believe that thousands of dolphins are killed each year during the slaughter. The Sea Shepherd Conservation Society is observing the fishermen and condemning the hunts.   “Babies and mothers will be torn from each other’s sides as some are taken for captivity, some are killed, and others are driven back out to sea to fend for themselves,” the organization said in a statement.

An Oscar-winning documentary about the practice, The Cove,  brought worldwide attention to the dolphin hunts. The movie brought worldwide attention to the dolphin hunts, and Kennedy’s comments and actions from conservation groups have only brought more attention to this controversial practice. Japan and the United States are in a stand-off that pits an ancient tradition against modern-day animal rights activism.

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NASA: Long-term warming trend continued in 2013

NASA’s Goddard Institute for Space Studies (GISS) has released an updated report on global temperature in 2013. According to a NASA press release, the GISS findings indicate that the trend of global warming continued in 2013. The 10 hottest years since 1880 have occurred since 2000, with the exception of 1998; 2005 and 2010 are the hottest yet recorded. The year 2013 tied with 2006 and 2009 as the seventh warmest year since 1880.

The GISS report states that Earth’s average global temperature was 58.3 degrees Fahrenheit (14.6 Celsius), 1.1 F (0.6 C) higher than in the middle of the 20th Century. Average global temperature has increased by 1.4 F (0.8 C) since 1880. 2013 was the 42nd warmest year on record for the continental United States, while it was the warmest year on record for Australia.

The report reiterates that annual weather patterns will yield fluctuations in average global temperature from one year to the next, but the long-term trend is clearly one of rising global temperature forced by rising levels of greenhouse gases. Scientists predict that each successive decade will be warmer than the last.

This trend is evident in different studies with different statistical methods; in addition to GISS, the Met Office Hadley Centre in the United Kingdom and NOAA’s National Climatic Data Center compile global temperature analyses, and all show the same increasing trend. GISS’s analysis used weather data from 1,000 meteorological stations around the world, sea-surface temperatures from satellite data, and measurements from Antarctic research stations; station status and urban heat islands are taken into account. Using the period from 1951 to 1980 as a baseline, the difference in surface temperature in a given month is calculated for each place. It has been 38 years since a year with colder than average temperature has been documented.

Commensurate with the rising temperatures is an increase in atmospheric carbon dioxide. This greenhouse gas retains heat that would otherwise bleed off into space. It occurs naturally, but is also released by the combustion of fossils fuels. The level of carbon dioxide in the atmosphere is higher now than at any time in the last 800,000 years, in large part due to man-made emissions. In 1880, the first year of GISS’s temperature record, carbon dioxide was at 285 parts per million. In 1960, it was at 315 parts per million. In 2013, it was at 400 parts per million.

“Long-term trends in surface temperatures are unusual and 2013 adds to the evidence for ongoing climate change,” said GISS climatologist Gavin Schmidt. “While one year or one season can be affected by random weather events, this analysis shows the necessity for continued, long-term monitoring.”

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Quasar sheds light on the underlying cosmic web

The standard cosmological model of structure formation hypothesizes that galaxies are situated in a vast cosmic web of matter, of which approximately 84 percent is dark matter. Computer simulations designed to depict the evolution of structures in the universe have indicated the distribution of dark matter across the universe, including the halos in which galaxies are born and the web of dark matter filaments that connect them and pervade the cosmos.

Now, those filaments have been observed for the first time. A team led by Sebastiano Cantalupo of the University of California at Santa Cruz used the Keck 1 Telescope at the W. M. Keck Observatory in Hawaii to detect an immense nebula stretching across 2 million light-years, twice as large as the largest nebula ever documented before. According a UC Santa Cruz press release, this diffuse gas cloud envelopes a bright quasar, UM287, which in turn illuminates the nebula. The quasar is a staggering 10 billion light-years from Earth.

A quasar is galactic nucleus that emits potent radiation driven by a supermassive black hole at its heart. Cantalupo and colleagues have previously discovered “dark galaxies”, which are either too small or too young to have generated stars. Dark galaxies are much denser and smaller components of the cosmic web than the vast nebula around UM287.

According to prior computer models, gravity makes normal matter follow the distribution of dark matter. Therefore, filaments of diffuse, ionized gas, such as those in the nebula around UM287, should describe a pattern similar to those derived from the dark matter simulations. In the case of UM287, the radiation from the quasar has lit up hydrogen gas in the nebula, revealing the structure of a filament of the cosmic web.

The hydrogen in the nebula emits ultraviolet light called Lyman alpha radiation. The expansion of the universe stretches this light from ultraviolet wavelengths to a visible wavelength of violet before it reaches Earth. Because the distance to the quasar is known, Cantalupo and team were able to determine the exact wavelength of the Lyman alpha radiation and fabricate a special filter for the Keck’s LRIS spectrometer. This allowed them to obtain an image of UM287 and the surrounding nebula at that wavelength.

Cantalupo and team observed that the amount of gas in the nebula around UM287 is at least ten times more than what would be expected based upon the simulations. Said Cantalupo, “ We think there may be more gas contained in small dense clumps within the cosmic web than is seen in our models. These observations are challenging our understanding of intergalactic gas and giving us a new laboratory to test and refine our models.”

The new findings were published in the January 19 issue of the journal Nature.

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Rare Martin Luther King Jr. recording released

A rare recording of a Martin Luther King  Jr. interview was recently released. On the tapes, he discusses President John F. Kennedy and the recent independence of African countries throughout the interview. The tapes will be played at the Civil Rights Museum near the Lorraine Motel where King was assassinated.

The reel-to-reel recordings were discovered years ago in an attic in Tennessee by a writer’s son. The recordings were made by a man who wanted to write a book about the civil rights movement, but the book was never completed.  The recordings have only recently been made public after magician David Copperfield  bought and donated the tapes to the Civil Rights Museum in Memphis, Tennessee.

In the interview, King spoke about his relationship to President Kennedy.  At the time, Kennedy was a Massachusetts senator, and he and Robert Kennedy intervened to have King released from a Georgia jail.

When asked if he thought the Kennedys had any influence on his release, King replied,   “Now, it is true that Sen. Kennedy did take a specific step,” King said. “He was in contact with officials in Georgia during my arrest and he called my wife, made a personal call and expressed his concern and said to her that he was working and trying to do something to make my release possible.”

While he believed that the Kennedys’ influence helped, King also believed that his supporters helped him as well.   “Well, I would say first that many forces worked together to bring about my release,” he said.  He added,   “I don’t think any one force brought it about, but you had a plurality of forces working together. I’m sure that the interest of the public, in general, all over America had something, a great deal to do with it.”

King also spoke in the interview about his method of nonviolent protest against Jim Crow laws and inequality in the South.  He said that nonviolent protest   “grows out of the whole concept of love, because if one is truly nonviolent that person has a loving spirit, he refuses to inflict injury upon the opponent because he loves the opponent.”

The interview also touched on King’s interest in African countries gaining independence in the 1960’s. He said that in order to spread democracy and equality to countries in Africa, Black people in America must experience justice and equality at home.

In the interview, King said some prophetic words about how the civil rights movement will be judged by history. “I’m convinced that when the history books are written in future years, historians will have to record this movement as one of the greatest epics of our heritage,” he said. “It represents struggle on the highest level of dignity and discipline.” On the holiday honoring Martin Luther King Jr., his words have definitely been proven to be true.

 

 

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United Nations: Don’t delay taking action on global warming

The Intergovernmental Panel on Climate Change (IPCC) warns that postponing action to combat climate change will only increase the costs and reduce the options for dealing with it, according to the final draft of an IPCC report obtained by The Associated Press.

According to the IPCC, global temperatures will continue to increase unless countries move quickly to cut carbon emissions. Current efforts aimed at reducing greenhouse gases just aren’t enough, the report said.

Carbon dioxide and other greenhouse gas emissions increased an average of 2.2 percent each year between 2000 and 2010. Emissions grew only 1.3 percent per year between 1970 and 2000.

The report said the two main explanations for increased carbon emissions are economic growth, which has risen dramatically, and population growth. The principal source of emissions worldwide is the burning of coal and oil, an activity that’s expected to rise, the report noted.

The IPCC experts say that unless “explicit efforts” are made to reduce carbon emissions, even increased conservation and improved efficiency won’t be able to stem their rise. The panel said emissions from the growing use of coal to generate electricity are projected to as much as triple by 2050 from 2010 levels unless efforts to improve clean energy technologies are “significantly accelerated.”

At the 2009 UN climate change conference in Copenhagen, an international group of climate negotiators agreed that global temperatures must increase by less than 2 degrees Celsius to avert the worst effects of climate change. That target, scientists say, requires atmospheric concentration of carbon dioxide to remain below 530 parts per million.

The report also said that to stay below 530 parts per million throughout the entire 21st century would require a reduction in carbon emissions between 40 and 70 percent of 2010 levels by 2050, or in just 36 years.

The panel emphasized the importance of making the transition to a low-carbon economy. To do this would require new kinds of investment, away from fossil fuels to non-carbon producing sources of energy.

To stabilize the atmospheric concentration of carbon dioxide, the main greenhouse gas, investments in fossil fuels would have to decline by $30 billion a year until 2029 while investment in non-carbon emitting energy sources would have to increase to $147 billion per year, the report said.

The panel noted that many clean, renewable energy sources are becoming more and more efficient and cost effective, but that many new technologies may continue to need government support to become commercially viable.

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Oceans, climates may be more common on super-Earths than previously thought

Terrestrial planets several times more massive than Earth appear to be abundant in our galaxy. However, many were thought to be water worlds, spheres of liquid water surrounding rocky cores. Now, a new study by Nicolas Cowan of Northwestern University and Dorian Abbot of the University of Chicago has found that super-Earths might actually be much more like their namesake than previously thought.

According a Northwestern University press release, Cowan and Abbot designed a model in which a super-Earth is treated like Earth itself. The modeled super-Earth has plate tectonics like Earth; in particular, seafloor pressure mediates the amount of water in the oceans and the mantle under the planet’s crust. Seafloor pressure is proportional to gravity – the higher the gravity, the higher the seafloor pressure. Cowan and Abbot’s model is innovative in addressing the consequences of higher gravity and seafloor pressure on a planet more massive than Earth.

The result of the model is that the planet’s mantle holds so much water that land is exposed on the surface; instead of a water word, the tectonically active super-Earth boasts continents and oceans. Exposed continents would give the super-Earth a carbon cycle controlled by surface temperatures, much like Earth, increasing the habitable zone of the super-Earth; a water-world would need to orbit its star within a much smaller habitable zone to support life.

Cowan and Abbot’s model is not without uncertainties; it is not known whether super-Earths even have tectonic plates, and the exact amount of water stored in Earth’s mantle is hard to estimate. Cowan and Abbot plan to continue their research on super-Earths. Their current findings were reported on January 8 at the 223rd Meeting of the American Astronomical Society, and the scientific paper will be published on January 20 in The Astrophysical Journal.