lunes, 1 de agosto de 2011

Space & Earth Updates - Nemesis is a myth & more:

Nemesis is a myth
Barringer Crater, also known as Meteor Crater, in Arizona. This crater was formed around 50,000 years ago by the impact of a nickel-iron meteorite. Near the top of the image, the visitors center, complete with tour buses on the parking lot, provides a sense of scale. Credit: National Map Seamless Viewer/US Geological Service

Danger looms from out of space: asteroids and comets are a threat to our planet. The history of Earth has always been punctuated by cosmic catastrophes. Several studies have claimed to have found periodic variations, with the probability of giant impacts increasing and decreasing in a regular pattern. Now a new analysis by Coryn Bailer-Jones from the Max Planck Institute for Astronomy (MPIA) shows those simple periodic patterns to be statistical artifacts. His results indicate either that the Earth is as likely to suffer a major impact now as it was in the past, or that there has been a slight increase impact rate events over the past 250 million years.

Nemesis is a myth
Danger looms from out of space: asteroids and comets are a threat to our planet. The history of Earth has always been punctuated by cosmic catastrophes. Several studies have claimed to have found periodic variations, with the probability of giant impacts increasing and decreasing in a regular pattern. Now a new analysis by Coryn Bailer-Jones from the Max Planck Institute for Astronomy (MPIA) shows those simple periodic patterns to be statistical artifacts. His results indicate either that the Earth is as likely to suffer a major impact now as it was in the past, or that there has been a slight increase impact rate events over the past 250 million years.




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US sets drought monitor's 'exceptional drought' record in July 
The percent of contiguous U.S. land area experiencing exceptional drought in July reached the highest levels in the history of the U.S. Drought Monitor, an official at the National Drought Mitigation Center at the University of Nebraska-Lincoln said.


Research yields world food potential 
The Australian National University and Bayer CropScience have signed a research agreement to develop new technology with the potential to produce higher yielding food crops.


New ponds take the waste out of wastewater 
Research by Flinders University’s School of the Environment has shown that a shallow, high-rate pond system to treat wastewater will slash the loss to evaporation as well as boosting the rates of removal of bacterial and viral pathogens.


Nature's expert witnesses: Plants tell of environmental pollution 
The poet William Blake once wrote that we could "see a world in a grain of sand." Today, environmental engineers are seeing the world beneath the surface through a greener part of nature: the trunks and branches of trees.


Melting glaciers signal climate change in Bolivia 
Scientists and peasants combine traditional farming techniques and cutting-edge research to grow food sustainably in the high Andes, where the ecology is rapidly changing.


European ALMA antenna brings total on Chajnantor to 16 
The first European antenna for the Atacama Large Millimeter/submillimeter Array (ALMA) has reached new heights, having been transported to the observatory’s Array Operations Site (AOS) on 27 July 2011. The 12-metre diameter antenna has arrived at the Chajnantor plateau, 5000 metres above sea level. Here, it joins antennas from the other international ALMA partners, bringing the total number at the AOS to 16.


Bringing carbon capture to a rock near you 
For coal-rich countries like the United States, the concept of "clean coal" is too intriguing to ignore. With the implementation of carbon capture and sequestration, America's most abundant energy resource could continue supplying half of the nation's electricity while emitting less carbon dioxide.


Record high radiation at crippled Japan nuke plant 
Tokyo Electric Power Co. (TEPCO) said Monday it had monitored record high radiation at the Fukushima Daiichi nuclear power plant crippled by the March 11 quake and tsunami.


AgriLife Research 'genetically fingerprinting' E. coli from watersheds 
The Lampasas and Leon Rivers watersheds have been listed as impaired by the state due to high counts of E. coli and other bacteria taken in the late 1990s, but from whom, what and where the contamination originates is unclear, say Texas AgriLife Research experts.


Organic carbon suggests Swedish lakes were less acidified 
During the 1970s and 1980s, researchers and policymakers became increasingly worried about multiple consequences of acidic emissions of sulfur dioxide and nitrogen oxides from the stacks of power stations, and eventually they were controlled. In Europe, there was much concern about the effects on Sweden's many lakes, which were found to be in some cases strikingly acidic. The Swedish government instituted a program of countering the acidification by adding thousands of tonnes of lime to the lakes.


Taking a fresh look at the weather 
Given the UK’s obsession with the weather, it would seem obvious that the basic understanding of how low pressure systems evolve has been known for a long time.


Beer-barrel bacteria breathe toxic brew 
University of New South Wales researchers have shown that they can safely destroy hazardous industrial toxins in groundwater arising from PVC plastic production by injecting naturally occurring bacteria into a contaminated Sydney aquifer – an Australian first that raises hope of cleaning up this and similarly polluted sites around the country.


Ancient tides quite different from today - some dramatically higher 
The ebb and flow of the ocean tides, generally thought to be one of the most predictable forces on Earth, are actually quite variable over long time periods, in ways that have not been adequately accounted for in most evaluations of prehistoric sea level changes.


Dawn spacecraft gets cozy with massive asteroid 
(AP) -- Scientists are busy poring over images of the massive asteroid Vesta, the first time it has been photographed up close.


Found: Heart of darkness 
Astronomers using the 10-meter Keck II telescope in Hawaii have confirmed in a new paper that a troupe of about 1,000 small, dim stars just outside the Milky Way comprise the darkest known galaxy, as well as something else: a treasure trove of ancient stars.


WHOI study reports microbes consumed oil in Gulf slick at unexpected rates 
More than a year after the largest oil spill in history, perhaps the dominant lingering question about the Deepwater Horizon spill is, "What happened to the oil?" Now, in the first published study to explain the role of microbes in breaking down the oil slick on the surface of the Gulf of Mexico, Woods Hole Oceanographic Institution (WHOI) researchers have come up with answers that represent both surprisingly good news and a head-scratching mystery.


Astronomy without a telescope: The unlikeliness of being 
History has proved time and again that mathematical modelling is no substitute for a telescope (or other data collection device). Nonetheless, some theoreticians have recently put forward a statistical analysis which suggests that life is probably very rare in the universe – despite the apparent prevalence of habitable-zone exoplanets, being found by the Kepler mission and other exoplanet search techniques.


Juno spacecraft prepares to launch 
In one week, NASA is scheduled to launch the Juno spacecraft on a mission to Jupiter, the largest planet in our solar system, to answer some fundamental questions about the gas giant and, in turn, about the processes that led to formation of our solar system.


Oxygen molecules found in deep space 
ESA's Herschel space observatory has found molecules of oxygen in a nearby star-forming cloud. This is the first undisputed detection of oxygen molecules in space. It concludes a long search but also leaves questions unanswered.


Greenhouse gas impact of hydroelectric reservoirs downgraded 
An international team of scientists has amassed the largest data set to date on greenhouse gas emissions from hydroelectric reservoirs. Their analysis, published today in the online version of Nature Geoscience, posits that these human-made systems emit about 1/6 of the carbon dioxide and methane previously attributed to them.


Aerosols affect climate more than satellite estimates predict 
Aerosol particles, including soot and sulfur dioxide from burning fossil fuels, essentially mask the effects of greenhouse gases and are at the heart of the biggest uncertainty in climate change prediction. New research from the University of Michigan shows that satellite-based projections of aerosols' effect on Earth's climate significantly underestimate their impacts.


Ancient glacial melting process similar to existing concerns about Antarctica, Greenland 
An analysis of prehistoric "Heinrich events" that happened many thousands of years ago, creating mass discharges of icebergs into the North Atlantic Ocean, make it clear that very small amounts of subsurface warming of water can trigger a rapid collapse of ice shelves.


Provided by PhysOrg.com