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Wed, 28 Sep 2016
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Telescope

Earth could be blindsided by asteroids, panel warns

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© NEAR Project/NLR/JHUAPL/Goddard SVS/NASA
Asteroid Eros, seen here by NASA's NEAR spacecraft, is 33 kilometres wide, making it the second largest near-Earth asteroid
Existing sky surveys miss many asteroids smaller than 1 kilometre across, leaving the door open to damaging impacts on Earth with little or no warning, a panel of scientists reports. Doing better will require devoting more powerful telescopes to asteroid hunting, but no one has committed the funds needed to do so, it says.

Near-Earth asteroids larger than 1 kilometre across could blast huge amounts of sunlight-blocking dust into Earth's atmosphere in an impact, causing devastating climate change. The US Congress asked NASA in 1998 to find 90 per cent of those in this size range within 10 years, a goal that has now nearly been reached.

Comment: See also: Confession: NASA can't keep up with killer asteroids


Meteor

Aorounga Impact Crater, Chad

© NASA
Astronaut photograph ISS020-E-26195 was acquired on July 25, 2009, with a Nikon D3 digital camera fitted with an 800 mm lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Expedition 20 crew.
Aorounga Impact Crater is located in the Sahara Desert, in north-central Chad, and is one of the best-preserved impact structures in the world. The crater is thought to be middle or upper Devonian to lower Mississippian (approximately 345 - 370 million years old) based on the age of the sedimentary rocks deformed by the impact. Spaceborne Imaging Radar (SIR) data collected in 1994 suggests that Aorounga is one of a set of three craters formed by the same impact event. The other two suggested impact structures are buried by sand deposits.

The concentric ring structure of the Aorounga crater - renamed Aorounga South in the multiple-crater interpretation of SIR data - is clearly visible in this detailed astronaut photograph. The central highland, or peak, of the crater is surrounded by a small sand-filled trough; this in turn is surrounded by a larger circular trough.

Telescope

New planet displays exotic orbit

© Artist's impression of an exoplanet (Nasa/JPL-Caltech)
Planets with retrograde orbits should be rare
Astronomers have discovered the first planet that orbits in the opposite direction to the spin of its star.

Planets form out of the same swirling gas cloud that creates a star, so they are expected to orbit in the same direction that the star rotates.

The new planet is thought to have been flung into its "retrograde" orbit by a close encounter with either another planet or with a passing star.

Magnify

London's earliest timber structure found during Belmarsh prison dig

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London's oldest timber structure has been unearthed by archaeologists from Archaeology South-East (part of the Institute of Archaeology at UCL). It was found during the excavation of a prehistoric peat bog adjacent to Belmarsh Prison in Plumstead, Greenwich, in advance of the construction of a new prison building. Radiocarbon dating has shown the structure to be nearly 6,000 years old and it predates Stonehenge by more than 500 years. Jacobs Engineering UK Ltd acted as the managing consultants, on behalf of the Ministry of Justice, and the work was facilitated by Interserve Project Services Ltd.

Magnify

Grave discovered at royal centre

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The grave contained artefacts including a bronze dagger with a gold band
The 4000-year-old burial chamber was uncovered near Forteviot, Perthshire.

Few remains of the body were found, but the archaeologists said it would have lain on a bed of quartz pebbles in sand, in a large stone coffin.

A bronze dagger with a gold band was discovered inside the grave, along with a leather bag, wooden objects and plant matter, which could be floral tributes.

The discovery was made by archaeologists from Glasgow and Aberdeen universities.

Info

Princeton pair sets world record in packing puzzle

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© Princeton University/Torquato Lab
Princeton researchers have beaten the present world record for packing the most tetrahedra into a volume. Research into these so-called packing problems have produced deep mathematical ideas and led to practical applications as well.
Finding the best way to pack the greatest quantity of a specifically shaped object into a confined space may sound simple, yet it consistently has led to deep mathematical concepts and practical applications, such as improved computer security codes.

When mathematicians solved a famed sphere-packing problem in 2005, one that first had been posed by renowned mathematician and astronomer Johannes Kepler in 1611, it made worldwide headlines.

Now, two Princeton University researchers have made a major advance in addressing a twist in the packing problem, jamming more tetrahedra -- solid figures with four triangular faces -- and other polyhedral solid objects than ever before into a space. The work could result in better ways to store data on compact discs as well as a better understanding of matter itself.

Info

Fungus Found in Humans Shown To Be Nimble in Mating Game

Providence, Rhode Island - Brown University researchers have discovered that Candida albicans, a human fungal pathogen that causes thrush and other diseases, pursues same-sex mating in addition to conventional opposite-sex mating.

Scientists have observed this same-sex mode of reproduction in other fungi, but this is the first time they have identified it in Candida albicans, the most common human fungal pathogen.

Details are highlighted in the August 2009 edition of the journal Nature.

"This discovery really surprised us," said Richard Bennett, assistant professor of biology in the Department Molecular Microbiology and Immunology at Brown. "Candida albicans has two mating types - a and alpha - and it was assumed that mating could only occur between these two cell types. We now know that a mechanism exists for same-sex mating, and thus sex could be more prevalent in this species than previously recognized."

Meteor

Confession: NASA can't keep up with killer asteroids

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© Unknown
NASA is charged with seeking out nearly all the asteroids that threaten Earth but doesn't have the money to do the job, a federal report says.

That's because even though Congress assigned the space agency this mission four years ago, it never gave NASA money to build the necessary telescopes, the new National Academy of Sciences report says. Specifically, NASA has been ordered to spot 90 percent of the potentially deadly rocks hurtling through space by 2020.

Even so, NASA says it's completed about one-third of its assignment with its current telescope system.

NASA estimates that there are about 20,000 asteroids and comets in our solar system that are potential threats to Earth. They are larger than 460 feet in diameter - slightly smaller than the Superdome in New Orleans. So far, scientists know where about 6,000 of these objects are.

Rocks between 460 feet and 3,280 feet in diameter can devastate an entire region but not the entire globe, said Lindley Johnson, NASA's manager of the near-Earth objects program. Objects bigger than that are even more threatening, of course.

Just last month astronomers were surprised when an object of unknown size and origin bashed into Jupiter and created an Earth-sized bruise that is still spreading. Jupiter does get slammed more often than Earth because of its immense gravity, enormous size and location.


Comment: And recently Venus too: Smashing days! New bright spot observed on Venus


Comment: Maybe NASA isn't keeping track of them, but someone is and they're not gonna tell us when something is about to hit.


Bad Guys

Diebold Quietly Patches Security Flaw in Vote Counting Software

© Premier Election Solutions (Diebold)

Premier Election Solutions, formerly Diebold, has patched a serious security weakness in its election tabulation software used in the majority of states, according to a lab that tested the new version and a federal commission that certified it.

The flaw in the tabulation software was discovered by Wired.com earlier this year, and involved the program's auditing logs. The logs failed to record significant events occurring on a computer running the software, including the act of someone deleting votes during or after an election. The logs also failed to record who performed an action on the system, and listed some events with the wrong date and timestamps.

Meteor

Traces of planet collision found

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© Unknown
In astronomical terms, the collision happened relatively recently
A Nasa space telescope has found evidence of a high-speed collision between two burgeoning planets orbiting a young star.

Astronomers say the cosmic smash-up is similar to the one that formed our Moon some four billion years ago, when a Mars-sized object crashed into Earth.

In this case, two rocky bodies are thought to have slammed into one another in the last few thousand years.

Details are to be published in the Astrophysical Journal.