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Updated: 7 hours 17 min ago

Inorganic semiconductor has DNA’s double-helix structure

14 September 2016
IEEE Spectrum: A new semiconductor material has been discovered that has the flexible yet robust double-helix structure of DNA. The researchers, at the Technical University of Munich, say the material also has extraordinary optical and electronic properties. Made of tin, iodine, and phosphorus, SnIP has a number of advantages over other prominent semiconductor materials, such as indium phosphide and gallium arsenide. Not only are its components more abundant and less toxic, it is much more flexible and its fibers can be split into smaller strands just nanometers thick. Such a material could have many applications, including for solar cells and thermoelectric devices.

Bolden "not a big fan" of private development of large launch vehicles

14 September 2016
Ars Technica: On 13 September NASA director Charles Bolden revealed that he thinks large launch vehicles such as the agency's Space Launch System (SLS) are best left to government development. He had originally been asked at the American Institute of Aeronautics and Astronautics' Space 2016 Conference for his opinion on the emerging market for small launch vehicles. But Bolden focused on the private large-rocket industry led by SpaceX and Blue Origin, which are developing rockets that will be direct competition for the SLS. He did not clarify why he views private development unfavorably. Costs for development and operations of the SLS are estimated to reach $60 billion through the 2030s. Both companies are developing rockets with reusable booster stages; the SLS will be fully expendable.

<em>Gaia</em> maps more than 1 billion stars

14 September 2016

BBC: The European Space Agency has released the first full-sky maps from its Gaia space telescope. Launched in 2013, Gaia is a follow-up to the Hipparcos satellite, which in the 1980s and 1990s cataloged the position, brightness, distance, and proper motion of 100 000 stars. In just three years Gaia has created a catalog 20 times as large, with position and brightness measurements for more than 1 billion stars in the Milky Way. The database also includes distance and proper motion for 2 million stars. By the end of its five-year mission, Gaia is expected to have collected a full set of measurements for nearly all the stars in the database. Beyond the four characteristics measured by HipparcosGaia will also be measuring stars' radial velocity—the motion of the stars toward or away from Earth as they sweep through the galaxy. The additional measurements will provide information about the structure and internal dynamics of the Milky Way, which should allow researchers to more accurately model the evolution of the galaxy.

A busy year of gravitational-wave delirium

14 September 2016
Extra Dimensions: A lot has happened since the historic LIGO detection. Will the excitement culminate in a 2016 Nobel for Thorne, Weiss, and Drever?

Physicist deported from Brazil to France awaits explanation

14 September 2016
Nature: For the past two months, particle physicist Adlène Hicheur has been under house arrest in his parents’ home in Vienne, France. He was placed there after being abruptly removed from his home in Rio de Janeiro, Brazil, by police on 15 July and escorted back to France. Four years earlier Hicheur, who has dual citizenship in France and Algeria, had been convicted in a French court of colluding with Al Qaeda in terrorist attacks. After serving his prison term, he accepted a position at the Federal University of Rio de Janeiro (UFRJ) in Brazil, where he had been working for the past three years until his sudden and unexplained removal by Brazilian authorities. Researchers at the UFRJ’s Laboratory of Elementary Particles have issued a petition, which has been signed by more than 300 people, calling for Hicheur's release.

Moon’s pull may help trigger earthquakes

13 September 2016

Atlantic: Although it is well known that the Moon is responsible for Earth’s tides, researchers say it might also affect earthquakes. Based on two decades' worth of data, Satoshi Ide of the University of Tokyo and colleagues have determined that some of the largest earthquakes have occurred when Earth’s crust was under the highest tidal stress. Those include the earthquakes that struck Sumatra on 26 December 2004; Maule, Chile, on 27 February 2010; and Tohoku-Oki, Japan, on 11 March 2011. The reason may be that the tugging of the Moon on Earth’s crust, although relatively weak, causes tiny faults to grow into a giant rupture. If so, future earthquake prediction methods may need to take into account the Moon’s pull, especially in earthquake-prone areas.

Medical isotope availability in doubt due to reactor closure

13 September 2016
Nature: Technetium-99m is commonly used as a radioactive tracer for a number of medical diagnostic scans. Next month the Chalk River nuclear-research reactor in Canada, which produces 20% of the world's technetium-99m, will shut down. Only six other reactors around the world, all of them quite old, produce the isotope. Medical facilities could face a severe technetium shortage if any of those reactors experience service disruptions before new reactors are brought on line in 2017 and 2018. A temporary shortage last occurred in 2009, when two reactors were turned off for repairs and maintenance. It is impossible to stockpile technetium-99m because it has a half-life of six hours. The isotope is a decay product of molybdenum-99, which has a half-life of 66 hours and is produced at the reactors via the bombardment of highly enriched uranium.

<em>Hubble</em> may have captured birth of a black hole

13 September 2016
New Scientist: The first observational evidence of a black hole forming may have been detected by the Hubble Space Telescope. In 2009 a red supergiant star, N6946-BH1, about 20 million light-years from Earth, was observed to flare brightly for several months before fading away. Although the star’s disappearance could be explained by its having merged with another star or being hidden by dust, the flaring didn’t last long enough, and dust should have dissipated by now. The most likely explanation, say Christopher Kochanek of the Ohio State University and colleagues, is that the massive star went supernova and then began collapsing in on itself and forming a black hole. If so, the material being sucked into the black hole should emit x rays, which the researchers hope to detect with the Chandra X-Ray Observatory.

Blue Origin announces planned heavy-lift rocket

13 September 2016
Washington Post: On 12 September Jeff Bezos announced that his company Blue Origin would be building a heavy-lift rocket named New Glenn. The rocket, which the company hopes to have ready for test flights by 2020, will feature a booster powered by seven BE-4 engines with a total of 3.85 million pounds of thrust at sea level. New Glenn will come in two-stage and three-stage variants. Like SpaceX's Falcon 9, the New Glenn booster will be designed to return to Earth with a controlled vertical landing. The announcement is a major step for Blue Origin, which is still in the testing phase of its reusable suborbital New Shepard rocket. Both of Blue Origin's rockets are named for American astronauts—John Glenn and Alan Shepard—and Bezos says that the company's next project will be named for Neil Armstrong.

How we found a planet orbiting Proxima Centauri

13 September 2016
A previously unnoticed error in archival data led astronomers to the signal that turned out to be a small planet circling the nearest star to the Sun.

Exoplanet stirs enthusiasm in scientists, press, and public

13 September 2016
Does the excitement generate too much overreach in the reporting?

A large galaxy made almost entirely of dark matter

12 September 2016
An as-yet unknown mechanism may have turned off the process of star formation.

Experimental black hole evaporation

9 September 2016
The physicist who 35 years ago proposed the construction of “dumb holes” to search for the analog of Hawking radiation is impressed by the recent experiment that looked for entangled thermal radiation from a tabletop horizon.

NASA probe begins its journey to asteroid Bennu

9 September 2016
Spaceflight Now: On 8 September, NASA successfully launched its OSIRIS-REx probe, destined for asteroid 101955 Bennu. The mission will last seven years, during which time the spacecraft will travel to Bennu, collect samples, and return them to Earth for analysis. The total distance traveled will be 4.4 billion miles. The launch marked the 111th for United Launch Alliance. Shortly after takeoff, OSIRIS-REx deployed its two solar arrays and communicated with ground control. If successful, the probe will return the largest amount of extraterrestrial material since the Apollo missions.

New theory argues heavy elements didn't immediately sink to Earth's core

9 September 2016
Science News: Gold, platinum, and other similar heavy elements are siderophile—when molten they tend to form alloys with iron. About 98% of Earth's siderophile elements are in the iron-dominated core, and the traditional view is that they sank to the core early in Earth's history. David Rubie of the University of Bayreuth in Germany and his colleagues are challenging that view. They argue that the bombardment of asteroids and comets that occurred during the first 100 million years of Earth's formation kept the planet's internal pressure and temperature high enough that siderophile elements were less likely to bond with iron. If that's true, then the heavy elements would have remained in Earth's mantle until they reacted with sulfur, crystallized, and fell toward the core. Rubie's group attributes the presence of precious metals in Earth's crust to the subsequent bombardment of asteroids, which deposited the elements on the surface.

US transport to space station is delayed again

9 September 2016
Problems with SpaceX and Boeing designs warrant a one-year extension to NASA’s Commercial Crew Program schedule, says a new report.

North Korea conducts fifth nuclear test

9 September 2016
Washington Post: On 9 September the US Geological Survey detected a magnitude 5.3 earthquake near North Korea's nuclear test site. Shortly thereafter, North Korean news media announced that the country had detonated another nuclear weapon. The magnitude of the seismic activity suggests that the test was much larger than the country's four previous tests. The test was timed to coincide with the 68th anniversary of the formation of North Korea's communist regime by Kim Il Sung, and it comes just days after the country tested several ballistic missiles that landed in the ocean near Japan.

United Airlines CEO cites <em>Farmers' Almanac</em> for winter plans

8 September 2016

USA Today: The CEO of United Airlines, Oscar Munoz, said in a radio interview that because "Farmers' Almanac is calling for a very nasty winter, particularly in Chicago ... our operating team is hard at work as to how are we going to accommodate passengers." Company spokesperson Charles Hobart said that United did not actually consult Farmers' Almanac and that Munoz was quoted out of context, but that has not stopped the company from receiving significant criticism. Several meteorologists have pointed out that the almanac does not have a good track record for its seasonal weather predictions; others compared consulting the almanac with consulting an astrologer. Hobart says the company actually has several aviation meteorologists on staff.

Analysis of cosmic microwave background radiation shows universe is isotropic

8 September 2016

Science: Cosmologists have long held that the universe is isotropic—fundamentally the same in all directions. A new study of the cosmic microwave background (CMB) radiation as mapped by the Planck spacecraft supports that assumption in the most stringent test yet. Daniela Saadeh and Andrew Pontzen of University College London and their colleagues used a supercomputer to look for CMB temperature and polarization patterns that would indicate a special direction in space. Based on their findings, the researchers estimate there is only a 1 in 121 000 chance that the universe is anisotropic. Their work increases the confidence in isotropism by an order of magnitude over previous analyses.