- Video: Solar Eclipse Seen From Space
- Dying Trees Make Way for Mice With Deadly Disease
- Drill Close to Reaching 14-Million-Year-Old Antarctic Lake
Posted: 07 Jan 2011 12:40 PM PST
The Earth-orbiting satellite Hinode caught this stunning video of the annular solar eclipse Jan. 4.
An annular eclipse occurs when the moon is slightly farther from Earth than usual and appears slightly smaller. When it moves between the Earth and sun, it covers the center of the sun, leaving a bright, fiery ring, or annulus, at the edge.
Hinode, a Japanese mission, studies the sun's magnetic fields and surface eruptions. The satellite carries three NASA-developed telescopes that capture different types of light:
This will be a good year for eclipse fans. With four partial-solar and two total-lunar eclipses upcoming, watch for more sun shots.
Posted: 07 Jan 2011 10:22 AM PST
SALT LAKE CITY — Recent diebacks of aspen trees in the U.S. West may end up increasing the risk posed by a lethal human pathogen, a new study suggests.
A tree-killing syndrome called sudden aspen decline that has wiped out swaths of trees across the West in the past decade has also changed the kinds, numbers and interactions of creatures living around the trees, researchers have found — including some carriers of human disease. Deer mice at hard-hit sites in 2009 were almost three times as likely to carry sin nombre virus — which can be fatal to humans — compared with mice in less-ravaged aspen stands, Erin Lehmer of Fort Lewis College in Durango, Colorado, and her colleagues reported Jan. 4 at the annual meeting of the Society for Integrative and Comparative Biology.
The deer mouse Peromyscus maniculatus looks ironically cute in pictures at meeting presentations, but the Centers for Disease Control and Prevention ranks it as the main rodent reservoir for sin nombre virus. Infected deer mice don't show many symptoms, but people inhaling virus wafting from mouse urine or saliva can get quite sick with hantavirus pulmonary syndrome.
Unknown to medicine until 1993, hantavirus pulmonary syndrome starts with muscle aches, chills, fever and stomach upset. Later, fluid fills the lungs; more than a third of victims have died. In 2010, the CDC logged 560 cases in 32 states stretching from California to Maine, but mostly in the West.
"Both plant diseases and animal diseases are rapidly emerging globally, and we should be looking for ways that the two might interact," said Richard Ostfeld of the Cary Institute of Ecosystem Studies in Millbrook, New York, who studies Lyme disease transmission.
What caused sudden aspen decline seems to be more complex than a single pathogen, Lehmer noted. Severe drought from the late 1990s into the 2000s stressed aspens, and then may have allowed cankers, fungi and other maladies to deliver death blows.
Lehmer and her colleagues compared aspen stands with minimal, moderate and high damage in the San Juan Mountains of Colorado. In places that still had most of their aspens, researchers found more species of small mammals than in the devastated plots. And in the healthier aspen stands, the most abundant small mammal was the montane vole, which doesn't make a good host for the virus.
In study sites that had lost at least two-thirds of their aspens, the researchers found fewer species of small mammals. The most abundant of those species was the deer mouse, which isn't as choosy about its habitat as the vole is. Lehmer speculated that infection might have risen among deer mice as their growing dominance in the landscape let them encounter each other more frequently and get into more mouse fights. Sin nombre spreads readily among rodents through bites.
Results from the aspen study so far seem to parallel the Lyme disease story, Ostfeld says. He and his colleagues have found that as people have fragmented habitat for wild animals, species that make poor hosts for the Lyme pathogen and its tick vector have dwindled in number. In these less diverse landscapes, however, the white-footed mice that carry Lyme disease thrive and readily pass around infections So what's bad for wild habitat ends up being bad for human health.
Image: David Cappaert/Michigan State University/Bugwood.org
Posted: 07 Jan 2011 08:19 AM PST
By Duncan Geere, Wired UK
Lake Vostok, which has been sealed off from the world for 14 million years, is about to be penetrated by a Russian drill bit.
The lake, which lies 2.5 miles below the icy surface of Antarctica, is unique in that it's been completely isolated from the other 150 subglacial lakes on the continent for such a long time. It's also oligotropic, meaning that it's supersaturated with oxygen: Levels of the element are 50 times higher than those found in most typical freshwater lakes.
Since 1990, the Arctic and Antarctic Research Institute in St. Petersburg in Russia has been drilling through the ice to reach the lake, but fears of contamination of the ecosystem in the lake have stopped the process multiple times, most notably in 1998 when the drills were turned off for almost eight years.
Now, the team has satisfied the Antarctic Treaty Secretariat, which safeguards the continent's environment, that it's come up with a technique to sample the lake without contaminating it. Valery Lukin told New Scientist: "Once the lake is reached, the water pressure will push the working body and the drilling fluid upwards in the borehole, and then freeze again." The next season, the team will bore into that frozen water to recover a sample whose contents can then be analysed.
The drill bit currently sits less than 328 feet above the lake. Once it reaches 65 to 98 feet, the mechanical drill bit will be replaced with a thermal lance that's equipped with a camera.
Time is short, however. It's possible that the drillers won't be able to reach the water before the end of the current Antarctic summer, and they'll need to wait another year before the process can continue.
When the sample can be recovered, however, it's hoped that it'll shed light on extremophiles — lifeforms that survive in extreme environments. Life in Lake Vostok would need adaptions to the oxygen-rich environment, which could include high concentrations of protective enzymes. The conditions in Lake Vostok are very similar to the conditions on Jupiter's moon Europa and Saturn's moon Enceladus, so the new data could also strengthen the case for extraterrestrial life.
Finally, anything living in the lake will have evolved in relative isolation for about 14 million years, so it could offer a snapshot of conditions on Earth long before humans evolved.
Updated 5:12 pm ET.
Image: Antarctica, with location of Lake Vostok circled in red.
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