Science News

Method Could Help Police, Firefighters, Elderly

---

University of Utah engineers showed that a wireless network of radio transmitters can track people moving behind solid walls. The system could help police, firefighters and others nab intruders, and rescue hostages, fire victims and elderly people who fall in their homes. It also might help retail marketing and border control.

---

Using updated information, NASA scientists have recalculated the path of a large asteroid. The refined path indicates a significantly reduced likelihood of a hazardous encounter with Earth in 2036.

---

Scientists have been warning for decades that the explosion of human activity since the industrial revolution is pushing the Earth's resources and natural systems to their limits.
The data confirm that 6 billion people are capable of generating a global geophysical force the equivalent to some of the great forces of nature – just by going about their daily lives.

---

NASA's Spitzer Space Telescope has discovered an enormous ring around Saturn -- by far the largest of the giant planet's many rings. The new belt lies at the far reaches of the Saturnian system, with an orbit tilted 27 degrees from the main ring plane.

---

Quantum mechanics could help build ultra-high-resolution electron microscopes that won't destroy living cells, according to MIT electrical engineers.

---

A new research project at Idaho National Laboratory (INL) and Argonne National Laboratory will use an innovative approach to learn how to get more use from nuclear fuel. The project demonstrates the U.S. Department of Energy's commitment to conduct more basic research on nuclear fuel recycling. Thanks to $2 million in funding from DOE's Office of Science, INL researcher Gilles Youinou aims to give nuclear scientists a better understanding of how elements within fuel rods respond to neutron irradiation.

---

In 1980, Luis Alvarez and his collaborators stunned the world with their discovery that an asteroid impact 65 million years ago probably killed off the dinosaurs and much of the the world's living organisms. But ever since, there has been an ongoing debate about how long it took for life to return to the devastated planet and for ecosystems to bounce back. Now, researchers from MIT and their collaborators have found that at least some forms of microscopic marine life — the so called "primary producers," or photosynthetic organisms such as algae and cyanobacteria in the ocean — recovered within about a century after the mass extinction. Previous research had indicated the process might have taken millions of years. It has taken so long to uncover the quick recovery because previous studies looked mostly at fossils in the layers of sediment from that period, and apparently the initial recovery was dominated by tiny, soft-bodied organisms such as cyanobacteria, which do not have shells or other hard body parts that leave fossil traces. The new research looked instead for "chemical fossils" — traces of organic molecules (compounds composed of mostly carbon and hydrogen) that can reveal the presence of specific types of organisms, even though all other parts of the organisms themselves are long gone. The new research, published in the Oct. 2 issue of Science, was led by Julio Sepúlveda, an MIT postdoc who carried out part of the work while still a graduate student at the University of Bremen, Germany, and MIT Professor of Geobiology Roger Summons, among others. The team had two major advantages that helped to make the new findings possible. One was a section of the well-known cliff face at Stevns Klint, Denmark, that happens to have an unusually thick layer of sediment from the period of the mass extinction — about 40 centimeters thick, compared to the few cm thickness of the layers that Alvarez originally studied from that period at Gubbio (Italy) and Stevns Klint (Denmark). And team members tapped one of the most powerful Gas Chromatograph-Mass Spectrometers (GC-MS) in the world, a device that can measure minute quantities of different molecules in the rock. MIT's advanced GC-MS is one of only a few such powerful instruments currently available at U.S. universities. When people look at microfossils in the sediments from the period but are unable to detect the chemical biomarkers with the level of sensitivity the MIT team was able to achieve, they "miss a big part of the picture," Sepúlveda says. "Many of these microorganisms" that were detected through molecular signatures "are at the base of the food chain, but if you don't look with biochemical techniques you miss them." The analysis clarified the sequence of events after the big impact. Immediately after the impact, certain areas of the ocean were devoid of oxygen and hostile to most algae, but close to the continent, microbial life was inhibited for only a relatively short period: in probably less than 100 years, algal productivity showed the first signs of recovery. In the open ocean, however, this recovery took much longer: previous studies have estimated that the global ocean ecosystem did not return to its former state until 1 to 3 million years following the impact. Because of the rebound of primary producers, Sepúlveda says "very soon after the impact, the food supply was not likely a limitation" for other organisms, and yet "the whole ecology of the system remained disrupted" and took much longer to recover. The findings provide observational evidence supporting models suggesting that global darkness after the impact was rather short. "Primary productivity came back quickly, at least in the environment we were studying," says Summons, referring to the near-shore environment represented by the Danish sediments. "The atmosphere must have cleared up rapidly," he says. "People will have to rethink the recovery of the ecosystems. It can't be just the lack of food supply" that made it take so long to recover. The team hopes to be able to study other locations with relatively thick deposits from the extinction aftermath, to determine whether the quick recovery really was a widespread phenomenon after the mass extinction. These findings seem to rule out one theory about how the global ecosystem responded to the impact, which held that for more than a million years there was a "Strangelove ocean" — a reference to the post-apocalyptic scenario in the movie Dr. Strangelove — in which all the primary producers remained absent for a prolonged period, Summons says. In addition to Sepúlveda and Summons, the work was carried out by Jens Wendler of the Friedrich-Schiller University in Jena, Germany, and Kai-Uwe Hinrichs of the University of Bremen. The work was funded by the DFG, European Graduate College Europrox and the NASA Astrobiology and Exobiology Programs. Source: MIT

---

Nearly 17 years after plucking the fossilized tooth of a new human ancestor from a pebbly desert in Ethiopia, an international team of scientists announced their reconstruction of a partial skeleton of the hominid, Ardipithecus ramidus, which they say revolutionizes our understanding of the earliest phase of human evolution.

---

"In 2009, cosmic ray intensities have increased 19% beyond anything we've seen in the past 50 years," says Richard Mewaldt of Caltech. "The increase is significant, and it could mean we need to re-think how much radiation shielding astronauts take with them on deep-space missions."

Trichodesmium has important role in nitrogen cycle and carbon sequestration

---

A new study of microscopic marine microbes, called phytoplankton, by researchers at Woods Hole Oceanographic Institution (WHOI) and the University of South Carolina has solved a ten-year-old mystery about the source of an essential nutrient in the ocean.

---

NASA scientists have discovered water molecules in the polar regions of the moon. Instruments aboard three separate spacecraft revealed water molecules in amounts that are greater than predicted, but still relatively small. Hydroxyl, a molecule consisting of one oxygen atom and one hydrogen atom, also was found in the lunar soil. The findings were published in Thursday's edition of the journal Science.

---

Through the ESA Advanced Research in Telecommunications Systems (ARTES) 5 project 'Textile Antennas', the Finnish Patria Aviation Oy company has demonstrated that an antenna can be built using textiles that can be worn and used for personal satellite communication.

---

Australian researchers have discovered a huge number of new species of invertebrate animals living in underground water, caves and "micro-caverns" amid the harsh conditions of the Australian outback.

UCLA professor leads first-ever effort to map moon's surface temperatures

---

NASA's Lunar Reconnaissance Orbiter (LRO), an unmanned mission to comprehensively map the entire moon, has returned its first data. One of the seven instruments aboard, the Diviner Lunar Radiometer Experiment, is making the first global survey of the temperature of the lunar surface while the spacecraft orbits some 31 miles above the moon.

---

Scientists from the University of Wisconsin-Madison Cooperative Institute for Meteorological Satellite Studies (CIMSS) are participating in a project designed to bridge the gap between current satellite capabilities and the advanced technology that will be part of the next generation of geostationary satellites.

---

University of Pennsylvania physicists working with glasses, a material that still perplexes researchers despite thousands of years of household and industrial use, have found new clues about how glasses age.

---

Stanford photo scientists are out to reinvent digital photography with the introduction of an "open-source" digital camera, which will give programmers around the world the chance to create software that will teach cameras new tricks.

---

Peering at single molecules within an organism that makes its home near thermal vents, Yale University scientists have discovered the structure of a key player in the creation of protein-making factories in humans.

---

A new technique for growing carbon nanotubes should be easier to integrate with existing semiconductor manufacturing processes.

---

NASA's Cassini spacecraft has obtained new, detailed images of the south polar region of Saturn's moon Enceladus. http://hypography.com/gallery/files/5/123416main_pia06248-516_thumb.jpgThe data reveal distinctive geological features and the most youthful terrain seen on the moon. These findings point to a very complex evolutionary history for Saturn's brightest, whitest satellite. Cassini's July 14 flyby brought it within 175 kilometers (109 miles) of the surface of the icy moon. The close encounter revealed a landscape near the south pole almost entirely free of impact craters. The area is also littered with house-sized ice boulders carved by unique tectonic patterns found only in this region of the moon. As white as fresh snow, Enceladus has the most reflective surface in the solar system. Previous Cassini flybys revealed Enceladus, in contrast to Saturn's other icy moons, has lightly cratered regions, fractured plains and wrinkled terrain. The new findings add to the story of a body that has undergone multiple episodes of geologic activity spanning a considerable portion of its lifetime. The moon's southernmost latitudes have likely seen the most recent activity. These same latitudes may also bear the scars of a shift in the moon's spin rate. If true, this speculation may help scientists understand why Enceladus has a tortured-looking surface, with pervasive crisscrossing faults, folds and ridges. The most remarkable images show ice blocks about 10 to 100 meters (33 to 328 feet) across in a region that is unusual in its lack of the very fine-grained frost that seems to cover the rest of Enceladus. "A landscape littered with building-sized blocks was not expected," said Dr. Peter Thomas, an imaging-team member from Cornell University, Ithaca, N.Y. "The minimal cover of finer material and the preservation of small, crossing fracture patterns in the surrounding areas indicate that this region is young compared to the rest of Enceladus." False color composites of this region, created from the most recent images, show the largest exposures of coarse-grained ice fractures seen anywhere on the moon, which also supports the notion of a young surface at southern latitudes. Some of the latest images may hint at the answer. The images revealed additional examples of a distinctive "Y-shaped" tectonic feature on Enceladus. In this unusual element, parallel ridges and valleys appear to systematically fold and deform around the south polar terrains. "These tectonic features define a boundary that isolates the young, south polar terrains from older terrains on Enceladus," noted Dr. Paul Helfenstein, an associate of the imaging team also at Cornell University. "Their placement and orientation may tell us a very interesting story about the way the rotation of Enceladus has evolved over time and what might have provided the energy to power the geologic activity that has wracked this moon." The apparent absence of sizable impact craters also suggests the south pole is younger than other terrain on Enceladus. All these indications of youth are of great interest to scientists, who have long suspected Enceladus as one possible source of material for Saturn's extensive and diffuse E ring, which coincides with the moon's orbit. Young terrain requires a means to generate the heat needed to modify the surface. Other Cassini instrument teams are working to understand data about the temperature, composition, particles and magnetic field. Together with image interpretation, these data can create a more complete picture. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. Source: NASA/JPL