Aliens

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California gives green light to space solar power
03:12 08 December 2009 by David Shiga
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Energy beamed down from space is one step closer to reality, now that California has given the green light to a deal involving its sale. But some major challenges will have to be overcome if the technology is to be used widely. On Thursday, the California Public Utilities Commission gave its blessing to an agreement that would see the Pacific Gas and Electric Company buy 200 megawatts of power beamed down from solar-power satellites beginning in 2016.


A start-up company called Solaren is designing the satellites, which it says will use radio waves to beam energy down to a receiving station on Earth.
The attraction of collecting solar power in space is the virtually uninterrupted sunshine available in geosynchronous orbit. Earth-based solar cells, by contrast, can only collect sunlight during daytime and when skies are clear.

Launch costs
But space-based solar power must grapple with the high cost per kilogram of launching things into space, says Richard Schwartz of Purdue University in West Lafayette, Indiana. Schwartz chaired a US National Academies committee that in 2001 wrote up an assessment of NASA's space-based solar power research. "If you're talking about it being economically viable for terrestrial power, it's a tough go," he says. Cal Boerman, Solaren's director of energy services, says the company designed its satellites with a view to keeping launch costs down. "We knew we had to come up with a different, revolutionary design," he says. A patent the company has won describes ways to reduce the system's weight, including using inflatable mirrors to focus sunlight on solar cells, so a smaller number can collect the same amount of energy.


Stay cool
But using mirrors introduces other challenges, including keeping the solar cells from overheating, says Schwartz. "You have to take care of heat dissipation because you're now concentrating a lot of energy in one place," he says. According to the company's patent, Solaren's solar cells will be connected to radiators to help keep them cool.


Though Boerman says the company believes it can make space-based solar power work, it is not expecting to crowd out other forms of renewable energy. Laws in California and other states require increasing use of renewable energy in coming years, he points out. "To meet those needs, we're going to need all types of renewable energy sources," he says.

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Nice Find Tech.. I'll keep an eye on thins one. I wonder if we have picked up on any radio or other frencuency transmission from this part of the the Galixy.

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2010 preview: Waiting for ET to phone

23 December 2009 by Richard Fisher
Magazine issue 2739.




West Virginia. It is 6 am on an April morning in 1960 and Frank Drake is freezing cold. He peers up towards the focal point of the radio telescope. He mounts a flimsy ladder to the top and climbs into a space about the size of a garbage can. For the next 45 minutes, he tunes the receiver inside, which feels like starting an old car. He climbs back down and begins to listen.

Drake and colleagues were conducting a seminal experiment: the first modern search for extraterrestrial life. For four months, the researchers used the Tatel Telescope in Green Bank to listen for any intelligent signals from the stars Tau Ceti and Epsilon Eridani that might be hidden on the same wavelength as radiation emitted naturally by hydrogen. Drake named the effort Project Ozma after the princess in the 0z books by Frank Baum, who wrote that he used a radio to learn of events there.

April 2010 will mark the 50th anniversary of the start of Project Ozma, and those involved in the search for extraterrestrial life, or SETI, will be raising a glass. Not only did the experiment inspire countless people to continue the search, it brought alien-hunting into the mainstream and arguably seeded the science of astrobiology.

Half a century on, SETI is a multi-pronged project, from the spectacular Arecibo Observatory in Puerto Rico to the Allen Telescope Array in California, which features around 40 small dishes working together as one mega-telescope. The ATA is only partly built and the SETI Institute will next year seek fresh cash to take it up to full strength, with 350 dishes sifting through huge tranches of the sky.

Researchers are also now looking for other forms of alien communication, such as brief pulses of light. This "optical SETI" approach was pioneered at Harvard University. Drake, now in his late seventies, plans next year to start up the most sensitive search yet for an alien laser beacon. It will use an unprecedented seven light detectors simultaneously. This will distinguish much weaker signals from starlight, and is largely immune to the false alarms that have plagued other experiments.

Frank Drake is still listening. Now he's watching too.

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They keep going and going and going…..

Mars Rover Makes Discovery While Spinning Its Wheels


Even though NASA's Mars rover Spirit has been trapped in the sand for months, the robot has still managed to report new facts about the red planet — all by just spinning its wheels.

These findings shed light on the history of water on Mars, which might once have supported life. For nearly six years, Spirit roamed Mars, experiencing a number of close calls. In fact, the solar-powered robot has driven backwards since its right front wheel jammed in 2006.

Spirit's most challenging ordeal yet began in April, when it got bogged down in a patch of loose soil on the edge of a small crater. As scientists plotted Spirit's escape for months, they dubbed the area Troy, after the city the ancient Greeks struggled against in myth for a decade. As frustrating as Spirit's dilemma has proven, it has yielded an unexpected insight.

"Spirit had to get stuck to make its next discovery," said geologist Ray Arvidson of the Washington University in St. Louis. "The rover's spinning wheels have broken through a crust, and we've found something supremely interesting in the disturbed soil."

Spirit broke through a dark reddish-brown crusty surface that was an inch or so thick, exposing loose, sandy material. As the rover tried to break free, its wheels began to churn the soil, uncovering even more sandy material, bearing "a higher concentration of sulfate that seen anywhere else on Mars," Arvidson said.

"Sulfates are minerals just beneath the surface that shout to us that they were formed in steam vents or hydrothermal pools, since hot water associated with these systems has sulfur in it," he explained. "These deposits are evidence of water-charged explosive volcanism. Such areas could have once supported life."

"Also, the robot found that the top of the sulfate material is crusty," Arvidson added. "Ancient sulfates probably formed this crust as they were processed by variations in climate associated with changes in Mars' orbit over millions of years."

The angle at which Mars' axis tilts can vary extremely, and during periods when its axis is highly tilted, the pole facing the sun gets warmer during the summer, shifting water to the equator as snow. The scientists think the warm soil causes the bottom layer of the snow to melt, and the water trickles into the sulfates, dissolving the water-soluble iron sulfates and forming a crust with the white calcium sulfates remaining.

"By being stuck at Troy, Spirit has been able to teach us about the modern water cycle on Mars," Arvidson said. The robot's saga at Troy has given scientists material evidence of past water on Mars on two time scales — ancient volcanic times, and cycles ongoing to the present day.

"We were never in one place long enough to really look at the layered nature of these deposits, which all fits with water migrating downward, giving us real insights into the history of water on Mars," Arvidson said.

As useful as all this time spent at Troy has proven, "we've sat here for more than six months," Arvidson said. "That's a long time to take measurements. We've learned a lot. Troy is a good place to be under siege, but we're ready to leave."Spirit may be able to break free to continue its journey after all.

"The right front wheel almost magically turned on a few days ago after we ran some voltage through it," Arvidson told SPACE.com. "Hopefully it can give us significant traction — the probability of extricating Spirit has gone up."