Physics Today Daily Edition
Nature: Several bright spots have been observed on the asteroid Ceres by NASA's Dawn spacecraft. The asteroid is known to have a significant amount of ice, but the way sunlight is being reflected indicates that the ice does not simply lie exposed on the asteroid's surface. New images from Dawn have revealed that some of the bright spots located in craters are still visible even when the crater walls should block them from the Sun. That observation suggests that, if the reflections are due to ice, the ice must have been pushed up to significant heights. One explanation could be volcano-like eruptions of the ice caused by fluctuating internal pressures within the asteroid. Similar eruptions could also be caused by sunlight warming the asteroid's surface as Ceres rotates from night to day, which could allow icy plumes to form that refreeze and then melt back down to the surface.
New York Times: Despite its reputation as a cool, cloudy country, the UK led Europe in the number of new solar installations in 2014. The combination of government subsidies and low prices because of high production rates from factories in China has driven the spread of solar in many European nations. And direct costs have now reached levels where solar can compete with natural gas without the need for subsidies. Thanks to those trends, European solar companies are building solar plants in developing nations such as Chile and India. In northern Chile, high altitude and low latitude allow solar to produce electricity at 80% the cost of coal, and 60% the cost of natural gas. Subsidies have even had some negative influences in the UK and Germany, where they've pushed up the cost of electricity overall. For large solar installations, the UK has begun auctioning guaranteed rates, which it believes will reduce the overall cost of electricity while still spurring solar growth.
BBC: When the European Space Agency's Rosetta was approaching comet 67P/Churyumov-Gerasimenko, its pictures of the cometary surface revealed 17 objects that appeared to have trails extending northward away from them. Such trails are common on Earth, where they are formed by wind depositing dust behind boulders or other objects. However, because the comet lacks an atmosphere, there isn't any wind. On Monday at the 46th Lunar and Planetary Science Conference, Stefano Mottola, the project leader of the Rosetta Lander Imaging System, announced that the team believes the trails were caused by splash saltation. The trails would have formed when objects impacted the surface and dislodged particles, which then fell back in the patterns seen.
Nature: One of the common methods of 3D printing shines UV light into the bottom of a container of liquid resin, which causes the resin at the very bottom of the basin to solidify. The solid part must then be pulled up to allow new liquid resin to flow in underneath, and the process is repeated. Because of the need to pause after the creation of each layer, the process can take hours to days, depending on the size of the object being printed. Now, Joseph DeSimone of the University of North Carolina at Chapel Hill and his colleagues have developed a new printer that can produce objects in just minutes. They made a reservoir for the liquid resin that has a bottom permeable to oxygen. The oxygen keeps the resin at the bottom from solidifying, resulting in a micron-thick layer of resin that remains liquid beneath the printed object. That allows the object to be printed continuously, with no delays as it is pulled upward. The technique also allows for 3D printing using rubbery materials that did not work in previous machines.
Science: The Department of Energy has named Steven Ashby, a computational mathematician, as the next director of Pacific Northwest National Laboratory (PNNL). Before joining PNNL in 2008 as its deputy director for science and technology, Ashby worked for more than 20 years at Lawrence Livermore National Laboratory. PNNL, the second largest of DOE's 10 national laboratories, has a $1 billion budget, with funding from not only DOE's Office of Science but also the National Nuclear Security Administration and other sources. Ashby says the lab's primary mission is to "understand, predict, and control complex adaptive systems," including the climate, electrical infrastructure, and national security.
BBC: The International Energy Agency (IEA) has announced that 2014 was the first time in 40 years, barring major economic downturns, that global carbon dioxide emissions did not increase. The data suggest that the steady levels were attributable to China's efforts to reduce coal consumption and other shifts in energy production in Organisation for Economic Co-operation and Development countries. The IEA says there have been three previous emissions slowdowns since it began taking records, but they were tied to economic events: the US recession in the early 1980s, the collapse of the Soviet Union in 1991, and the 2009 global recession.
Science: For the past two years, Representative Lamar Smith (R-TX) has criticized NSF for its peer-review-based grant approval process for funding research that does not support the national interest. Under his guidance a subcommittee of the House science committee has been examining a selection of grants issued by NSF over the past decade. However, in an interview on Wednesday, Smith said the investigation has led him to believe that NSF's grant approval process is indeed the best option for making such complex decisions.
Nature: Marty Burke of the University of Illinois at Urbana-Champaign and his colleagues have developed a system that may significantly simplify a time-intensive process for chemists: creating complex synthetic molecules. The computerized network of pumps and syringes manipulates a library of commercially available molecular compounds to combine them in the order programmed by the user. Similar techniques have been developed in the past, but Burke's machine includes a process that automates the removal of excess material and isolates the newly combined molecule for use in subsequent steps. The result is the first automatic system that can produce ring-shaped and branching molecules.
BBC: Jupiter's Ganymede is the largest moon in the solar system and is also unusual in that it has a significant magnetic field. Joachim Saur of the University of Cologne in Germany and his colleagues have been using the Hubble Space Telescope to study Ganymede's magnetic field and aurora. The interactions between the magnetic fields of Jupiter and Ganymede cause wobbles in Ganymede's field that can be seen in the movements of the aurora. Saur's team compared their observations with various models of Ganymede's internal structure. They found that Jupiter's magnetic field creates a secondary fluctuation in Ganymede's aurora that would be easily explained by interacting with a body of saltwater. The Hubble data most closely match a model of the moon that includes a subsurface ocean, though that ocean could be anywhere from 100 km deep with a salt content of 5 kg/L to just 10 km deep with 50 kg/L salt concentration.
Science: A clinical test will begin this month in which ultrasound will be used to deliver chemotherapy drugs to treat brain cancer. Ultrasound will briefly open the blood–brain barrier, which normally prevents drugs from reaching the brain. The risk is that ultrasound has the potential to directly damage brain tissue, so testing the technique on humans may not be as successful as earlier tests performed on rodents. Separately, Sunnybrook Research Institute's Kullervo Hynynen, who first tested ultrasound's effect on the blood–brain barrier, and his colleagues have used the technique on the brains of mice and found it eliminated abnormal clumps similar to those present in patients with Alzheimer's disease. They reported that the cognitive ability of the treated mice was restored.