Science & TechnologyS


Clock

Arctic reindeer abandon use of internal clock to survive in extreme cold


ANI
Fri, 12 Mar 2010 19:34 UTC
A new study has shown that Arctic reindeer have abandoned use of the internal clock that drives the daily biological rhythms in other organisms, in order to live under extreme conditions in the Arctic.

"Our findings imply that evolution has come up with a means of switching off the cellular clockwork," said Andrew Loudon of the University of Manchester.

"Such daily clocks may be positively a hindrance in environments where there is no reliable light-dark cycle for much of the year," he added.

Light-dark cycles drive hormone rhythms via a circuit that involves the eye and nervous system projections to structures involved in regulating hormone rhythms, in particular melatonin, Loudon explained.
Read More...
Telescope

New Pluto images show changing atmosphere

Dan Cadel
John Hopkins News-Letter
Thu, 11 Mar 2010 17:05 UTC
Image
© NASA
Photos newly released by NASA this February show the most detailed pictures of Pluto that have ever been taken. The Hubble telescope captured these images using its Advanced Camera for Surveys as recently as 2003. To put this in perspective, each picture is only a few pixels in size, and through computer analysis, the pictures were overlaid and enhanced to create a composite image of higher quality.

The significance of these pictures comes in comparisons. These new pictures were studied as part of a collection that included Hubble images from 1994, 2002 and 2003, as well as ground-based telescope images taken in 1988 and 2002. Among the changes observed over this time span are a doubling of the mass of Pluto's atmosphere, as well as a brightening of the North pole of the planet, and a darkening of the Southern hemisphere.

Pluto's surface has regions of different materials, resulting in the orange, white and black blotches of color. The atmosphere of Pluto is dynamic, resulting in this change in appearance. The increase in atmospheric mass is likely due to melting of nitrogen ice, which releases gas into the atmosphere.

Pluto's seasonal changes differ greatly from those on Earth. The eccentricity of Pluto's orbit makes it such that its seasons are not equal in length, since the planet accelerates as it gets closer to the sun. By comparison, Earth's orbit is relatively circular, resulting in seasons of equal length and intensity based on the tilt of Earth's axis.

One year on Pluto is equal to 248 Earth years, making each season on Pluto very long. Since its discovery, less than half a Pluto-year has elapsed.
Read More...
Info

Star Predicted to Blast Through the Solar System

Ian O'Neill
Discovery News
Sat, 13 Mar 2010 02:40 UTC
Gliese
© ESOThe orange dwarf approaches. Could this be the scene as Gliese 710 crashes through our solar system?
In 1.5 million years time, the solar system could be in for a rough ride.

An orange dwarf star named Gliese 710 is powering in our direction and an astronomer has calculated an 86 percent chance of the interstellar interloper smashing through the Oort Cloud, located in the outermost reaches of our solar system.

This could have the devastating effect of scattering the icy Oort Cloud objects (or OCOs), causing them to plunge toward the sun and the inner planets, potentially bombarding Earth with comets.

Vadim Bobylev of the Pulkovo Astronomical Observatory in St Petersburg has published revised calculations of local star positions and velocities to arrive at this prediction.
Read More...
Meteor

Comet-Kaze Strikes The Sun

Ray Villard
Discovery News
Sat, 13 Mar 2010 13:53 UTC
At first glance it looks like aliens are using the sun for target practice. A string of bullet-shaped streaks of light appear to be shooting straight toward the sun.

These are proverbial snowballs in Hell, plunging 300 miles per second toward a fiery end in the sun's atmosphere.

Read More...
Sun

Mysterious Speed Record May Explain Mystery of Sun


SPACE.com
Fri, 12 Mar 2010 16:05 UTC
A new study reports that the top of the gigantic conveyor belt of plasma moving inside the sun has been running at record-high speeds for the past five years.

The phenomenon might be the reason why the sun has continued to have so few sunspots recently when it should be ramping up the production of these surface-blotching storms.

"I believe this could explain the unusually deep solar minimum we've been experiencing," said David Hathaway, a solar physicist at NASA and co-author of a new study describing the findings, in a NASA statement. "The high speed of the conveyor belt challenges existing models of the solar cycle and it has forced us back to the drawing board for new ideas."
Read More...
Info

Australian archaeologists uncover 40,000-year-old site

Amy Coopes
Agence France-Presse
Wed, 10 Mar 2010 15:54 UTC
Sydney - Australian archaeologists have uncovered what they believe to be the world's southernmost site of early human life, a 40,000-year-old tribal meeting ground, an Aboriginal leader said Wednesday.

The site appears to have been the last place of refuge for Aboriginal tribes from the cannon fire of Australia's first white settlers, said Michael Mansell of the Tasmanian Aboriginal Centre.

The find came during an archaeological survey ahead of roadworks near Tasmania's Derwent River and soil dating had established the age of the artefacts found there.

"When the archaeological report came out it showed that (life there) had gone back longer than any other recorded place anywhere else in Tasmania, dating back to 40,000 years," Mansell told AFP.

Up to three million artefacts, including stone tools, shellfish fragments and food scraps, were believed to be buried in the area, which appeared to have been a meeting ground for three local tribes.

They died out after white settlers arrived in the late 18th century.

"They (settlers) hunted people here to this place and shot them just so they could get the land," said Mansell. "Many others were imprisoned until they died."
Read More...
Sherlock

UK: 51 Decapitated Skeletons 'Scandinavian Vikings' Discovered


BBC News
Fri, 12 Mar 2010 00:00 UTC
Image
© UnknownArchaeologists are trying to link the find to historical events
Fifty-one decapitated skeletons found in a burial pit in Dorset were those of Scandinavian Vikings, scientists say.

Mystery has surrounded the identity of the group since they were discovered at Ridgeway Hill, near Weymouth, in June.

Analysis of teeth from 10 of the men revealed they had grown up in countries with a colder climate than Britain's.

Archaeologists from Oxford believe the men were probably executed by local Anglo Saxons in front of an audience sometime between AD 910 and AD 1030.

The Anglo Saxons were increasingly falling victim to Viking raids and eventually the country was ruled by a Danish king.
Read More...
Magnify

How Electricity Moves Through Cells: Finding Has Implications for Improving Energy Efficiency


ScienceDaily
Fri, 12 Mar 2010 00:00 UTC
Image
© University of MinnesotaThis illustration shows the molecular details of a multi-protein battery and wire that generates and conducts biological electricity.
Researchers at the University of Minnesota have created a molecular image of a system that moves electrons between proteins in cells. The achievement is a breakthrough for biology and could provide insights to minimize energy loss in other systems, from nanoscale devices to moving electricity around the country.

The research, led by Carrie Wilmot, an associate professor in the College of Biological Sciences, is published in the March 12 issue of Science.

"Evolution has been fine-tuning electricity in organisms for a lot longer than humans have been using it," Wilmot says. "We can learn a lot from nature about how to use it more efficiently. This new glimpse at how the body uses electricity could lead to nanotechnology to shrink electronic circuitry even further or a more efficient grid to provide power to homes and businesses."
Read More...
Telescope

Auroras From Space


Space Weather
Fri, 12 Mar 2010 10:58 UTC
Image
© US Navy Fleet Numerical Meteorology and Oceanography Center
A solar wind stream is buffeting Earth's magnetic field and stirring up geomagnetic activity around the Arctic Circle. "On March 11th," reports Paul McCrone, "the DMSP F-18 weather satellite recorded a dramatic auroral event over northern Canada."

McCrone processed the image at the US Navy's Fleet Numerical Meteorology and Oceanography Center in Monterey, California. It shows a broad swirl of Northern Lights stretching from Newfoundland across Quebec to the Hudson Bay. "I included an infrared image to show that this is really not a cloud," he says. Auroras are not strong sources of infrared radiation, but clouds are, so infrared images can be used to distinguish the two.

The solar wind continues to blow. High-latitude sky watchers should remain alert for auroras.
Read More...
Meteor

Bright Sun-Grazing Comet


Space Weather
Fri, 12 Mar 2010 10:51 UTC
Image
© SOHO
A newly-discovered comet is plunging toward the sun and probably will not survive. The encounter is too close to the sun for human eyes to see, but the Solar and Heliospheric Observatory (SOHO) is able to monitor the action using an opaque disk to block the sun's glare.

The doomed comet is probably a member of the Kreutz sungrazer family. Named after a 19th century German astronomer who studied them in detail, Kreutz sungrazers are fragments from the breakup of a giant comet at least 2000 years ago. Several of these fragments pass by the sun and disintegrate every day. Most are too small to see but occasionally a big fragment--like this one--attracts attention.

Click here to launch a 12-hour time-lapse animation
Read More...