Science & Technology
Space scientists and government officials are tracking two massive objects that are hurtling toward Earth, but only one, a dead satellite the size of a bus, is expected to hit somewhere on the globe.
Explosions of small stars, long thought to create stellar dust, actually sweep dust away, scientists discovered.
For years, researchers have observed swirling dust clouds around systems called recurring novas, which periodically explode. New images of a distant nova have now overturned astronomers' long-standing assumption that the dust originates in the blasts.
For years, researchers have observed swirling dust clouds around systems called recurring novas, which periodically explode. New images of a distant nova have now overturned astronomers' long-standing assumption that the dust originates in the blasts.
I can show people evidence of real strikes inflicting local and regional damage less than a century ago. Even more compelling are the frequent kiloton-level detonations our early warning satellites see in the earth's atmosphere.
Within the United States space community there is a growing concern over "space situational awareness." We are beginning to understand that it is essential to identify and track virtually everything in earth orbit. Some of these objects, down to a few centimeters in size, present a potential threat to commercial and civil space operations such as the International Space Station.
What then should we do? What role should the US Government, and specifically the US DoD play in what everyone agrees is an international concern?
Within the United States space community there is a growing concern over "space situational awareness." We are beginning to understand that it is essential to identify and track virtually everything in earth orbit. Some of these objects, down to a few centimeters in size, present a potential threat to commercial and civil space operations such as the International Space Station.
What then should we do? What role should the US Government, and specifically the US DoD play in what everyone agrees is an international concern?
Washington - A large U.S. spy satellite has lost power and could hit the Earth in late February or early March, government officials said Saturday.
The satellite, which no longer can be controlled, could contain hazardous materials, and it is unknown where on the planet it might come down, they said. The officials spoke on condition of anonymity because the information is classified as secret. It was not clear how long ago the satellite lost power, or under what circumstances.
The satellite, which no longer can be controlled, could contain hazardous materials, and it is unknown where on the planet it might come down, they said. The officials spoke on condition of anonymity because the information is classified as secret. It was not clear how long ago the satellite lost power, or under what circumstances.
Mars has an ethereal, tenuous atmosphere at less than 1 percent the surface pressure of Earth, so scientists working on The University of Arizona's High Resolution Imaging Experiment, or HiRISE, are challenged to explain the complex, wind-sculpted landforms they're now seeing in unprecedented detail.
The HiRISE camera on NASA's Mars Reconnaissance Orbiter, the most powerful camera to orbit another planet, can see 20-inch-diameter features while flying at about 7,500 mph between 155 and 196 miles above the Martian surface. HiRISE is giving researchers eye-opening new views of wind-driven Mars geology.
The HiRISE camera on NASA's Mars Reconnaissance Orbiter, the most powerful camera to orbit another planet, can see 20-inch-diameter features while flying at about 7,500 mph between 155 and 196 miles above the Martian surface. HiRISE is giving researchers eye-opening new views of wind-driven Mars geology.
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| "HiRISE keeps showing interesting things about terrains that I expected to be uninteresting," said HiRISE principal investigator Alfred McEwen of the UA's Lunar and Planetary Laboratory. |
Researchers in the laboratory of Miami University chemist Hong-Cai Zhou, associate professor of chemistry and biochemistry, report development of a microporous material with the highest methane storage capacity ever measured. It can hold almost one-third more methane than the U.S. Department of Energy's (DOE) target level for methane-powered cars, they report in a new study.
Methane stands out among various alternative fuels when its profusion and availability are considered. However, the lack of an effective, economic and safe on-board storage system is one of the major technical barriers preventing methane-driven automobiles from competing with the traditional ones, say the study authors.
Methane stands out among various alternative fuels when its profusion and availability are considered. However, the lack of an effective, economic and safe on-board storage system is one of the major technical barriers preventing methane-driven automobiles from competing with the traditional ones, say the study authors.
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Scientists studying microbial communities and the growth of sedimentary rock at Mammoth Hot Springs in Yellowstone National Park have made a surprising discovery about the geological record of life and the environment. Their discovery could affect how certain sequences of sedimentary rock are dated, and how scientists might search for evidence of life on other planets.
"We found microbes change the rate at which calcium carbonate precipitates, and that rate controls the chemistry and shape of calcium carbonate crystals," said Bruce Fouke, a professor of geology and of molecular and cellular biology at the University of Illinois.
"We found microbes change the rate at which calcium carbonate precipitates, and that rate controls the chemistry and shape of calcium carbonate crystals," said Bruce Fouke, a professor of geology and of molecular and cellular biology at the University of Illinois.
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| The extent to which microorganisms influence calcium carbonate precipitation has been one of the most controversial issues in the field of carbonate sedimentology and geochemistry. Separating biologically precipitated calcium carbonate from non-biologically precipitated calcium carbonate is difficult. |
Learning and memory - abilities associated with a brain or, at the very least, neuronal activity - have been observed in protoplasmic slime, a unicellular organism with multiple nuclei.
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| Slime moulds demonstrate primitive learning and memory. |
Contrary to expectations for a small icy body, much of the comet dust returned by the Stardust mission formed very close to the young sun and was altered from the solar system's early materials.
When the Stardust mission returned to Earth with samples from the comet Wild 2 in 2006, scientists knew the material would provide new clues about the formation of our solar system, but they didn't know exactly how.
When the Stardust mission returned to Earth with samples from the comet Wild 2 in 2006, scientists knew the material would provide new clues about the formation of our solar system, but they didn't know exactly how.
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| ©NASA/JPL |
| Combined long- and short-exposure images captured during the Stardust flyby of the comet Wild 2. |
The Arecibo Observatory in Arecibo, Puerto Rico will observe a newly discovered asteroid on Jan. 27-28, as the object called 2007 TU24 passes within 1.4 lunar distances, or 334,000 miles, from Earth.
The asteroid, estimated at between 150 and 600 meters in diameter - about 500 feet to 1,900 feet, or the size of a football field, at 360 feet, to the size of Chicago's 110-story Sears Tower, at 1,454 feet - was discovered by the University of Arizona's Catalina Sky Survey in October 2007. It poses no threat to Earth, but its near approach gives Arecibo astronomers a golden opportunity to learn more about potentially hazardous near-Earth objects.
"We don't yet know anything about this asteroid," said Mike Nolan, head of radar astronomy at the Puerto Rico observatory. Such objects pass near Earth with relative frequency, he said - approximately one every five years or so - but it's rare that astronomers have enough advance notice to plan for rigorous observing.
The asteroid, estimated at between 150 and 600 meters in diameter - about 500 feet to 1,900 feet, or the size of a football field, at 360 feet, to the size of Chicago's 110-story Sears Tower, at 1,454 feet - was discovered by the University of Arizona's Catalina Sky Survey in October 2007. It poses no threat to Earth, but its near approach gives Arecibo astronomers a golden opportunity to learn more about potentially hazardous near-Earth objects.
"We don't yet know anything about this asteroid," said Mike Nolan, head of radar astronomy at the Puerto Rico observatory. Such objects pass near Earth with relative frequency, he said - approximately one every five years or so - but it's rare that astronomers have enough advance notice to plan for rigorous observing.
Comment: Look at that! An asteroid is having a close encounter with the Earth and a spy satellite might hit the Earth, which no one is sure what kind of materials it contains, yet harmful as reported. Interesting that SOTT has carried a few editorials, very recently, on the subject of threats to Earth from space debris:
Wars, Pestilence and Witches
Cosmic Turkey Shoot
The Hazard to Civilization from Fireballs and Comets
New Light on the Black Death: The Cosmic Connection