Showing posts with label Science. Show all posts
Saturday 15 November 2014
Comet lander shuts down after sending data
Science
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US
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Batteries aboard the European Space Agency’s Philae comet lander drained, shutting down the washing machine-sized probe after an adventurous and largely unscripted 57-hour mission.
Carried aboard the orbiting Rosetta mothership, Philae floated to the surface of comet 67P/Churyumov-Gerasimenko on Thursday, but failed to deploy anchoring harpoons.
Upon contacting the comet’s unexpectedly hard surface, it bounced back up into space twice then came to rest at a still-unknown location about 1 km (0.6 mile) from its original target.
Photos and other data relayed by Philae show it finally landed against a cliff or crater wall where there was little sunlight to recharge its batteries. Racing against the clock, scientists activated a series of automated experiments, the first to be conducted from the surface of a comet.
Before dying, Philae defied the odds and radioed its science results back to Earth for analysis.
Its last task was to reposition itself so that as the comet soars toward the sun, Philae’s batteries may recharge enough for a follow-on mission. “Perhaps when we are nearer to the sun we might have enough solar illumination to wake up the lander and re-establish communication,” spacecraft operations manager Stephan Ulamec said in a statement.
Scientists are particularly interested in learning about the chemical composition of any organic molecules in samples drilled out from the comet’s body.
Comets are believed to be pristine remnants from the formation of our solar system some 4.6 billion years ago. They contain rock and ice that have preserved ancient organic molecules like a time capsule and may provide insight into how the planets and life evolved.
Philae's drill descended more than 25 cm (10 inches) on Friday, penetrating the comet’s surface.
Rosetta in August became the first spacecraft to put itself into orbit around a comet. It will accompany the comet as it travels toward the sun for at least another 13 months.
REUTERS
Tuesday 7 October 2014
LED there be light: 3 share Nobel for blue diode
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Science
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Tech
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(AP) — An invention that promises to revolutionize the way the world lights its homes and offices — and already helps create the glowing screens of mobile phones, computers and TVs— earned a Nobel Prize on Tuesday for two Japanese scientists and a Japanese-born American.
By inventing a new kind of light-emitting diode, or LED, they overcame a crucial roadblock for creating white light far more efficiently than incandescent or fluorescent bulbs. Now LEDs are pervasive and experts say their use will only grow.
"Incandescent light bulbs lit the 20th century; the 21st century will be lit by LED lamps," the Nobel committee said in announcing its award to Japanese researchers Isamu Akasaki and Hiroshi Amano and naturalized U.S. citizen Shuji Nakamura.
Their work, done in the early 1990s, led to a fundamental transformation of technology for illumination, the committee said. And when the three arrive in Stockholm to collect their awards in early December, "they will hardly fail to notice the light from their invention glowing in virtually all the windows of the city."
Nakamura, 60, is a professor at the University of California, Santa Barbara. Akasaki, 85, is a professor at Meijo University and Nagoya University in Japan, while Amano, 54, is also at Nagoya. Akasaki and Amano made their inventions while working at Nagoya, while Nakamura was working separately at the Japanese company Nichia Chemicals.
At a press conference, Nakamura said he is "happy to see that my dream of LED lighting has become a reality. Nowadays we can buy energy-efficient light bulbs in the supermarket and help reduce energy use. I hope this helps to reduce global warming too," he said, reading from a prepared statement.
Asked earlier if he realized the importance of his research early on, he told reporters, "Nobody can make a cellphone without ... my invention."
Akasaki told a nationally-televised news conference in Japan that he had faced skepticism about his research bearing fruit. "But I never felt that way," he said. "I was just doing what I wanted to do."
Before their work, scientists had long been able to produce red and green light with LEDs. But they needed a blue LED as well to make white light, a goal sought for about 30 years. The three new Nobel laureates created blue LEDs.
It's "a fundamental invention that is rapidly changing the way we bring light to every corner of the home, the street and the workplace," H. Frederick Dylla, the executive director and CEO of the American Institute of Physics, said in a statement.
For illuminating schools, homes and offices, "it's quite possible this will change everything. All the light sources could easily become blue-LED-based light sources," said Mark Rea, director of the Lighting Research Center at the Rensselaer Polytechnic Institute in Troy, New York.
Nadarajah Narendran, director of research at the center, estimated the share of illumination by LED lights in homes, offices, streets and industries is approaching 10 percent in the United States. Within five years, he said, that fraction will probably exceed 30 percent as prices come down.
People can already buy LED lights for their homes at a fairly affordable price, he said.
In poor countries, such lights are replacing alternatives like kerosene lanterns, he said.
"It's touched (people) from the poor to the rich in a very short time frame," he said.
The Nobel committee noted that for people not supplied by power grids, LED lamps may be feasible to use with cheap solar power because they consume so little energy.
The committee also said the efficiency of LEDs helps save the Earth's resources because about one-fourth of world electricity consumption is used for lighting.
Not all reactions to the prize were laudatory. Many colleagues of Nick Holonyak, a retired professor from the University of Illinois who invented the red LED in 1962, have long said his work was unjustly overlooked by the Nobel committee. In the past, Holonyak, now 85, has said the award was far less important to him than the work.
But on Tuesday, Holonyak said the work done by the new winners was built on achievements by himself and dozens of others who worked with him.
"I find this one insulting," he said in an interview in Urbana, Illinois.
Last year's physics award went to British scientist Peter Higgs and Belgian colleague Francois Englert for helping to explain how matter formed after the Big Bang.
On Monday, U.S.-British scientist John O'Keefe split the Nobel Prize in medicine with Norwegian couple May-Britt Moser and Edvard Moser for breakthroughs in brain research that could pave the way for a better understanding of diseases like Alzheimer's.
The Nobel award in chemistry will be announced Wednesday, followed by the literature award on Thursday, the Nobel Peace Prize on Friday and the economics prize on Monday.
Worth 8 million kronor ($1.1 million) each, the Nobel Prizes are always handed out on Dec. 10, the anniversary of prize founder Alfred Nobel's death in 1896. Besides the prize money, each laureate receives a diploma and a gold medal.
Nobel, a wealthy Swedish industrialist who invented dynamite, provided few directions for how to select winners, except that the prize committees should reward those who "have conferred the greatest benefit to mankind."
This year's physics prize, the Nobel committee said, was given with that idea in mind.
Monday 6 October 2014
Google Doodle celebrates explorer who headed the Kon-Tiki expedition
Google has used its latest animated home page doodle to celebrate the life of Norwegian ethnographer explorer Thor Heyerdahl, best known for leading the Kon-Tiki expedition of 1947, who was born on this day in 1914.
In the expedition, Heyerdahl and his crew of five sailed a balsa wood raft 5,000 miles westwards from Peru towards French Polynesia in an attempt to prove his hypothesis that the islands were colonised from the Americas, rather than from the Asian mainland, as had previously been thought.
The point of the journey was to travel on a raft built using materials and technology that would have been available to pre-Colombian Americans, i.e. those living on the continent before the arrival of Europeans, headed by Christopher Columbus, in 1492.
People found it hard to believe that such distances could be covered using such basic vessels. The journey was successful, with the Kon-Tiki making landfall in the Tuamoto Islands on 7 August 1947, 101 days after setting sail.
Tuesday 16 September 2014
Boeing, SpaceX poised to build 'space taxis' for NASA
Aerospace
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NASA
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Science
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USA
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(Reuters) - NASA will partner with Boeing and SpaceX to build commercially owned and operated "space taxis" to fly astronauts to the International Space Station, ending U.S. dependence on Russia for rides, U.S. Senator Bill Nelson said on Tuesday.
The U.S. space agency also considered a bid by privately owned Sierra Nevada Corp., but opted to award long-time aerospace contractor Boeing and California's SpaceX with contracts potentially worth billions of dollars, to develop, certify and fly their seven-passenger capsules.
SpaceX is run by technology entrepreneur Elon Musk, also the CEO of electric car manufacturer Tesla Motors.
Nelson spoke on CNN ahead of a planned NASA news conference scheduled for later on Tuesday at the Kennedy Space Center in Florida.
The contract has taken on new urgency in recent months, given escalating tensions with Russia over its annexation of the Crimea region of Ukraine.
Boeing's CST-100 spaceship would launch aboard Atlas 5 rockets, built by United Launch Alliance, a partnership of Lockheed Martin and Boeing. SpaceX, which already has a $1.3 billion NASA contract to fly cargo to the space station, intends to upgrade its Dragon freighter to carry astronauts.
Terms were not immediately disclosed. NASA has said that in addition to test flights, the awards would include options for between two and six operational missions.
Before the end of 2017, NASA wants to be flying astronauts commercially from the United States, ending Russia's monopoly on space station crew transport. The agency currently pays $70 million per person for rides on Russian Soyuz capsules, the only flights available for astronauts since the retirement of the U.S. space shuttles in 2011.
China, the only other country to fly people in orbit besides the United States and Russia, is not a member of the 15-nation space station partnership.
NASA has spent about $1.5 billion since 2010 investing in partner companies under its Commercial Crew program. Boeing and SpaceX have won most of NASA's development funds.
The Commercial Crew program is based on a successful predecessor public-private partnership that created two cargo lines to the station, a research laboratory that flies about 260 miles (418 km) above Earth. In addition to SpaceX, NASA has a $1.9 billion contract with Orbital Sciences Corp for resupply missions.
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