Comet Likely Culprit In Tunguska Blast

Tunguska Blast

From Science News:

Night-shining clouds created after space shuttle launches may offer clues into the cause of the Tunguska event, a mysterious blast which rocked southern Siberia more than a century ago.

Thin clouds have appeared at abnormally high altitudes over polar regions following space shuttle launches on several occasions in the past decade. These noctilucent, or night-shining, clouds typically occur in summer and lie at altitudes of about 85 kilometers, in a layer of the atmosphere called the thermosphere, says Michael C. Kelley, an atmospheric physicist at Cornell University. Kelley and his colleagues suggest in the July 28 Geophysical Research Letters that data gleaned from analyses of these high-flying clouds, as well as knowledge about the speed at which shuttle exhaust wafted to polar regions, now hint that the Tunguska blast of June 1908 (SN: 6/21/08, p. 5) resulted from a comet slamming into Earth’s atmosphere.

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Laser Propulsion: Wild Idea May Finally Shine

From Space.com:

New laser propulsion experiments are throwing light on how to build future hypersonic aircraft and beam spacecraft into Earth orbit.

Indeed, a "Lightcraft revolution" could replace today's commercial jet travel. Passengers would be whisked from one side of the planet to the other in less than an hour - just enough time to get those impenetrable bags of peanuts open. Furthermore, beamed energy propulsion can make flight to orbit easy, instead of tenuous and dangerous.

That's the belief of Leik Myrabo an aerospace engineering professor at Rensselaer Polytechnic Institute in Troy, NY. He's an expert in directed energy applications, aerospace systems, space prime power, and advanced propulsion.

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Collision Course: The Need for Better Space Junk Regulations

From Popular Mechanics:

With 3000 satellites and a growing arsenal of space junk, Earth’s orbit is a crowded area. If debris continues to accumulate, low Earth orbit could eventually become too congested for safe satellite use and space travel. Unfortunately, space junk is hard to regulate and even harder to clean up. Here’s an overview of existing space junk laws and some proposals for addressing the problems with debris in space.

Close calls in orbit happen all the time—scientists estimate that launch vehicles and other objects come within striking distance of one other over 1000 times a day. So when tracking reports on Feb. 10, 2009, predicted that Iridium 33, a 12-foot-long, 1200-pound communications satellite, and a 1-ton Russian military sat, Kosmos 2251, would pass within less than half a mile of each other, no one was alarmed. It wasn’t the closest call predicted for that day, or even the closest pass for any of the 66 Iridium satellites that coming week. But at the time of the predicted approach, Iridium 33 fell silent.

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Fermi Paradox Points to Fewer Than 10 Extraterrestrial Civilizations

From Technology Review:

The absence of alien probes visiting the solar system places severe limits on the number of advanced civilizations that could be exploring the galaxy.

The Fermi paradox focuses on the existence of advanced civilizations elsewhere in the galaxy. If these civilizations are out there--and many analyses suggest the galaxy should be teeming with life--why haven't we seen evidence of them?

Today Carlos Cotta and Álvaro Morales from the University of Malaga in Spain add another angle to the discussion. One consideration is the speed at which a sufficiently advanced civilization could colonize the galaxy. Various analyses suggest that using spacecraft that travel at a tenth of the speed of light, a colonization wave could take some 50 million years to sweep the galaxy. Others have calculated that it may be closer to 13 billion years, which may explain why we have yet to spot extraterrestrials.

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Mercury Released By Dental Amalgam Fillings Are Not High Enough To Cause Harm, FDA Finds

The FDA has found that while elemental mercury has been associated with adverse health effects at high exposures, the levels released by dental amalgam fillings are not high enough to cause harm in patients. (Credit: iStockphoto)

From Science Daily:

ScienceDaily (July 31, 2009) — The U.S. Food and Drug Administration today issued a final regulation classifying dental amalgam and its component parts – elemental mercury and a powder alloy—used in dental fillings. While elemental mercury has been associated with adverse health effects at high exposures, the levels released by dental amalgam fillings are not high enough to cause harm in patients.

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Skype Could Be Cut Off For Good Over Dispute

(Paul Rogers/The Times)

From Times Online:

Skype might have to shut down because of a dispute over the core technology used to make the internet telephone system work.

EBay, which paid $2.6 billion (£1.6 billion) for the voice-over-the-internet system in 2005, is facing a court battle with the original founders of the company who retained the rights to the technology at the heart of the system.

EBay admitted in a regulatory filing that it might have to close down the company. It said it was trying to develop alternative software but if that did not work, or if eBay lost the right to the original software: "Skype would be severely and adversely affected and the continued operation of Skype's business as currently conducted would likely not be possible."

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Nap Time! One-Third Of Americans Do It

From Live Science:

A mid-day nap is more common than you might think in America.

One-third of U.S. adults nap on a typical day, according to a new survey from the Pew Research Center.

Naps are more common among men than women, and more common among the poor than the rich.

Naps can be good for you. A study last year in the journal Nature Neuroscience found a 90-minute daytime nap helped test subjects remember things better.

And naps are natural. Humans are bi-phasic sleepers, experts say, which means we're meant to sleep in bouts, not long stretches.

The new survey of 1,488 adults was released this week.

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My Comment: I am one of the guilty nappers.

Why Does Coke From a Glass Bottle Taste Different?

The Usual Suspects: Various container materials might impart slight changes to Coke's flavor. Courtesy The Coca-Cola Company

From Popular Science:

It doesn’t. That’s what Coca-Cola’s spokespeople say, anyway. “The great taste of Coca-Cola is the same regardless of the package it comes in,” they insist. Rather, they say, “the particular way that people choose to enjoy their Coke can affect their perception of taste.” Sure, most people would agree that the cola is indeed delicious and refreshing, and pouring it into a glass or serving it over ice could influence the sensation of its flavor. But is it possible that the subtle variation in taste that some notice among aluminum cans, plastic bottles and glass bottles is more than just a psychological effect of their soda-consumption rituals?

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Space Shuttle Endeavour Successfully Lands Back At Florida -- News Roundups

This NASA image taken by the crew aboard the International Space Station shows the space shuttle Endeavour shortly after the shuttle and station began their post-undocking separation on July 28, 2009. Endeavor is scheduled to land Friday at the Kennedy Space Center in Florida. The STS-127 crew was on a 13-day service mission to the International Space Station. (UPI Photo/Kevin Dietsch)

Shuttle Back After 16-Day Mission -- New York Times

KENNEDY SPACE CENTER, Fla. — The shuttle Endeavour closed out a grueling 16-day space station assembly mission with a smooth Florida landing on Friday, bringing Japan’s first long-duration astronaut back to Earth after four and one-half months in orbit.

Approaching from the south after a high-speed computer-orchestrated descent, the mission commander, Mark Polansky, took over manual control 50,000 feet above the Florida spaceport, banked to line up on runway 15 and guided the 110-ton shuttle to a picture-perfect touchdown at 10:48 a.m. Eastern time.

“Welcome home. Congratulations on a superb mission from beginning to end,” astronaut Alan Poindexter radioed from mission control in Houston. “Very well done.”

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Space Shuttle Endeavour lands at the shuttle landing facility at Kennedy Space Center.
Photo AFP

More News On Today's Landing Of The Space Shuttle Endeavour

Space shuttle Endeavour lands safely after 16-day mission -- AFP
Shuttle Endeavour, 7 astronauts return to Earth -- AP
Space shuttle Endeavour returns home to Florida -- Reuters
Shuttle Endeavour Lands Safely -- FOX News
Space shuttle Endeavour returns home -- UPI
Space shuttle touches down safely -- BBC
Endeavour lands safely -- CBC
Cdn astronaut Julie Payette lands aboard shuttle Endeavour after 16-day mission -- Canadian Press
Astronaut Koichi Wakata didn't change underwear for a month -- Times Online

Italian Archaeologists Find Lost Roman City Of Altinum Near Venice

From Times Online:

The bustling harbour of Altinum near Venice was one of the richest cities of the Roman empire. But terrified by the impending invasion of the fearsome Germanic Emperor Attila the Hun, its inhabitants cut their losses and fled in AD452, leaving behind a ghost town of theatres, temples and basilicas.

Altinum was never reoccupied and gradually sunk into the ground. The city lived on in Venetian folk tales and historical artefacts but its exact position, size and wealth gradually faded into obscurity.

Now, using aerial photography of the region, Italian archaeologists have not only located the city, but have produced a detailed map revealing its remarkably intact infrastructure and showing it to be slightly larger than Pompeii.

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Panel Wants Deep Space, Not Landings as U.S. Goal

From The New York Times:

A panel examining the future of the United States’ human spaceflight program will suggest that the Obama administration may want to skip the part about landing on other worlds.

That could, panel members said Thursday, enable the National Aeronautics and Space Administration to send astronauts to more corners of the solar system more quickly while keeping within a limited budget. But it would also eliminate the possibility of astronauts leaving new iconic footprints on the Moon or Mars for a couple of decades.

At a public meeting in Cocoa Beach, Fla., the 10-member panel discussed at length the possibilities of where NASA might go next and how it might get there.

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Crew Inspects Shuttle And Preps For Landing Friday

From Space Daily:

Twin satellite deployments and a check of the systems that will control Endeavour's return home to the Kennedy Space Center, Florida, are on tap today as the shuttle leads the International Space Station in orbit.

The crew was awakened at 1:03 a.m. CDT to the sounds of "I Got You Babe," performed by Sonny and Cher. The song was a special request for Koichi Wakata, the first Japan Aerospace Exploration Agency astronaut to serve as a long-duration resident of the station. Wakata spent 133 days as an Expedition 18, 19 and 20 crewmember, and will be returning home after 138 days in space.

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Human Activity Is Driving Earth's 'Sixth Great Extinction Event'

The leatherback turtle is endangered - but scientific reports expose worrying signs of mass extinctions among other wildlife species. Photograph: Frans Lemmens/Getty Images

From The Guardian:

Population growth, pollution and invasive species are having a disastrous effect on species in the southern hemisphere, a major review by conservationists warns.

Earth is experiencing its "sixth great extinction event" with disease and human activity taking a devastating toll on vulnerable species, according to a major review by conservationists.

Much of the southern hemisphere is suffering particularly badly, and Australia, New Zealand and neighbouring Pacific islands may become the extinction hot spots of the world, the report warns.

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Mysterious Bright Spot Found On Venus

A new, bright spot in the clouds of Venus was found by amateur astronomer Frank Melillo on 19 July (Illustration: Melillo/Maxson/ESA/University of Wisconsin-Madison/ALPO)

From New Scientist:

A strange spot emerged on Venus last week, and astronomers are not sure what caused it. They hope future observations will reveal whether volcanic activity, turbulence in the planet's atmosphere, or charged particles from the sun are to blame.

Amateur astronomer Frank Melillo of Holtsville, New York, first spotted the new feature, which is brighter than its surroundings at ultraviolet wavelengths, on the planet's southern hemisphere on 19 July. That same day, an amateur observer in Australia found a dark spot on Jupiter that had been caused by a meteoroid impact.

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Red Hot: Ferrari Previews F430 Successor

Ferrari 458 Italia Set for Frankfurt Debut this Fall: Ferrari today revealed its latest V8-powered sports car, the Pininfarina-designed 458 Italia. A successor to the current F430, the 458 gets a new, high-compression 4.5-liter V8 producing 570 horsepower and 398 pounds-feet of torque. Top Speed: 202 mph. Ferrari

From Popsci.com:

There's nothing like the curves of a new Ferrari to bring optimism back to the table. Ferrari today revealed its latest V8-powered sports car, the 458 Italia. The new model will succeed the current V8 hottie, the F430. Sporting a sexy new design by long-time Ferrari styling partner Pininfarina, the 458 Italia gets a new, high-compression 4.5-liter V8 producing 570 horsepower and 398 pounds-feet of torque. Top Speed: 202 mph. That makes it the first stock V8 Ferrari to break the 200-mph mark.

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Will Comets Wipe Out Life On Planet Earth? -- News Roundup

According to scientists Jupiter and Saturn have protected life on Earth for hundreds of millions of years by catching and batting away dangerous comets Photo: PA

Comet 'Unlikely To Wipe Out Earth' -- The Telegraph

The Earth is being protected from comets, thanks to the gravitational pulls of Saturn and Jupiter, according to new research

It is the plot of many a Hollywood science fiction thriller - a comet on a direct collision course with Earth destined to wipe out all known life.

But the producers of Deep Impact and other blockbusters might be wide of the mark, scientists have found, as new evidence suggests comets pose less of a threat to life on earth than previously imagined.

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More News On Comets And Striking The Earth

Comets probably won't destroy life on Earth, researchers say -- National Post
Comets probably won't cause the end of life as we know it: study -- AFP
Comets Not So Likely to Smash Into Earth and Kill Us All -- Discover Magazine
Comets From Edge of Solar System Unlikely to Hit Earth -- Space.com
Comet Collisions Won’t Spark The End Of The World -- Red Orbit
Doomsday Comet Less Likely, Calculations Show -- Discovery
Crashing Comets Not Likely The Cause Of Earth's Mass Extinctions -- Science Daily

White Roofs Catch On as Energy Cost Cutters

A Wal-Mart store in Chino, Calif., has both a cool roof and solar panels to cut its energy use. J. Emilio Flores for The New York Times

From The New York Times:

SAN FRANCISCO — Returning to their ranch-style house in Sacramento after a long summer workday, Jon and Kim Waldrep were routinely met by a wall of heat.

“We’d come home in the summer, and the house would be 115 degrees, stifling,” said Mr. Waldrep, a regional manager for a national company.

He or his wife would race to the thermostat and turn on the air-conditioning as their four small children, just picked up from day care, awaited relief.

All that changed last month. “Now we come home on days when it’s over 100 degrees outside, and the house is at 80 degrees,” Mr. Waldrep said.

Their solution was a new roof: a shiny plasticized white covering that experts say is not only an energy saver but also a way to help cool the planet.

Relying on the centuries-old principle that white objects absorb less heat than dark ones, homeowners like the Waldreps are in the vanguard of a movement embracing “cool roofs” as one of the most affordable weapons against climate change.

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Fiery Images As Killer Volcano That Claimed 36,000 Lives Stirs Once More

Ticking timebomb: Islanders thought they had avoided
another disaster after things went quiet last year

From The Telegraph:

An amateur photographer has captured new images of the re-awakening of the world's most famous volcano.

In a breathtaking series Marco Fulle, who specialises in shots of comets, has photographed the Anak Krakatoa against a backdrop of constellations such as the Big Dipper.

These stunning pictures show the latest activity during the rebirth of the infamous volcano which holds a long-standing record for causing the highest number of human deaths ever - a staggering 36,000 in 1883.

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Who Should Get the H1N1 Vaccine First?

A doctor at the Centers for Disease Control examines specimens in an effort to develop new influenza vaccines. James Gathany / CDC / Reuters

From Time Magazine:

World health officials are carefully watching the H1N1/09 swine flu virus as it makes it way through the Southern Hemisphere, which is currently in the thick of its flu season. They are particularly interested in seeing how severely the virus affects infected people in parts of Africa, South America and Australia, since their illnesses could be a good predictor of how aggressive the virus will be when flu season returns to the rest of the world in the fall.

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Adult Brain Can Change Within Seconds

The human brain can adapt to changing demands even in adulthood, but MIT neuroscientists have now found evidence of it changing with unsuspected speed. Their findings suggest that the brain has a network of silent connections that underlie its plasticity. (Credit: iStockphoto/Sebastian Kaulitzki)

From Science Daily:

ScienceDaily (July 30, 2009) — The human brain can adapt to changing demands even in adulthood, but MIT neuroscientists have now found evidence of it changing with unsuspected speed. Their findings suggest that the brain has a network of silent connections that underlie its plasticity.

The brain’s tendency to call upon these connections could help explain the curious phenomenon of “referred sensations,” in which a person with an amputated arm “feels” sensations in the missing limb when he or she is touched on the face. Scientists believe this happens because the part of the brain that normally receives input from the arm begins “referring” to signals coming from a nearby brain region that receives information from the face.

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