David_Aldrich's Blog

This article just came down yesterday.

In case you missed it...

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The official start of Hurricane Season starts June 1st, just more than two weeks away.

May 13, 2008: NASA's Phoenix Mars Lander is preparing to end its long journey and begin a three-month mission to taste and sniff fistfuls of Martian soil and buried ice. The lander is scheduled to touch down on the Red Planet on Sunday, May 25th.

Phoenix will enter the top of the Martian atmosphere at almost 13,000 mph. In seven minutes, the spacecraft must complete a challenging sequence of events to slow to about 5 mph before its three legs reach the ground. Confirmation of the landing could come as early as 7:53 p.m. EDT.

Right: An artist's concept of NASA's Phoenix Mars Lander a moment before its 2008 touchdown on the arctic plains of Mars. Pulsed rocket engines control the spacecraft's speed during the final seconds of descent. [Larger image]

"This is not a trip to grandma's house. Putting a spacecraft safely on Mars is hard and risky," said Ed Weiler, associate administrator for NASA's Science Mission Directorate at NASA Headquarters in Washington. "Internationally, fewer than half of all attempts to land on Mars have succeeded."

Rocks large enough to spoil the landing or prevent opening of the solar panels present the greatest known risk. However, images from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter, detailed enough to show individual rocks smaller than the lander, have helped lessen that risk.

"We have blanketed nearly the entire landing area with HiRISE images," said Ray Arvidson of Washington University in St. Louis, chairman of the Phoenix landing-site working group. "This is one of the least rocky areas on all of Mars and we are confident that rocks will not detrimentally impact the ability of Phoenix to land safely."

Above: The landing site chosen for NASA's Mars Phoenix Lander, at about 68 degrees north latitude, is much farther north than the sites where previous spacecraft have landed on Mars. [more]

Earlier in 2002, NASA's Mars Odyssey orbiter discovered that plentiful water ice lies just beneath the surface throughout much of high-latitude Mars. NASA chose the Phoenix proposal over 24 other proposals to become the first endeavor in the Mars Scout program of competitively selected missions.

"Phoenix will land farther north on Mars than any previous mission," said Phoenix Project Manager Barry Goldstein of NASA's Jet Propulsion Laboratory, Pasadena, Calif.

The solar-powered robotic lander will manipulate a 7.7-foot arm to scoop up samples of soil and underground ice. Onboard laboratory instruments will analyze the samples. Cameras and a Canadian-supplied weather station will supply other information about the site's environment.

Right: An artist's concept: Months after landing, Phoenix begins to shut down operations as winter sets in. Far-northern latitudes on Mars experience no sunlight during winter, depriving the solar-powered lander of electricity. Frost covering the region as the atmosphere cools will eventually bury Phoenix in ice.

"The Phoenix mission not only studies the northern permafrost region, but also takes the next step in Mars exploration by determining whether this frosty region, which may encompass as much as 25 percent of the Martian surface, is habitable," said Peter Smith, Phoenix principal investigator at the University of Arizona, Tucson.

One research goal is to assess whether conditions at the site ever have been favorable for microbial life. The composition and texture of soil above the ice could give clues to whether the ice ever melts in response to long-term climate cycles. Another important question is whether the scooped-up samples contain carbon-based chemicals that are potential building blocks and food for life itself.

Stay tuned to Science@NASA for updates. And good luck, Phoenix!

Editor: Dr. Tony Phillips | Credit: Science@NASA

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
150 PM EDT MON MAY 12 2008

...PUBLIC INFORMATION STATEMENT...

...A LATE SEASON SNOW FELL OVER SOUTH CENTRAL PENNSYLVANIA...

AN UNUSUALLY INTENSE AND COLD LATE SEASON STORM DUMPED HEAVY RAIN
OVER MUCH OF CENTRAL PENNSYLVANIA OVERNIGHT SUNDAY INTO MONDAY
MORNING. HOWEVER IT MAY HAVE SURPRISED SOME TO WAKE AND FIND SOME WET
SLUSHY SNOW COVERING THE LANDSCAPE EARLY TODAY.

A LOOK INTO THE RECORD BOOKS SUGGESTS THAT THIS WAS AMONG THE LATEST
DATES SNOW HAS BEEN OBSERVED FOR MUCH OF THE REGION. WHILE MOST OF
THE OFFICIAL REPORTS WE RECEIVED TODAY WERE FOR JUST A TRACE OF
SNOW...MEANING IT WAS ENOUGH TO BE SEEN BUT NOT QUITE ENOUGH TO
STICK A RULER IN TO MEASURE...SEVERAL CALLS WERE PASSED ALONG
INDICATING SOME OF OUR HIGHER ELEVATIONS RECEIVED ENOUGH TO COAT THE
GROUND OR EVEN BEND SOME OF THE TREES OVER WITH THE WEIGHT OF THE
HEAVY WET WHITE STUFF.

THE FOLLOWING ARE SOME OF THE LATEST DATES WHERE SNOW HAS BEEN
MEASURED IN THE PAST.

IN ALTOONA WHERE RECORDS HAVE BEEN KEPT SINCE 1948...THE LATEST SNOW
ON RECORD WAS .4 INCHES SET ON MAY 4TH 1976.

IN EBENSBURG WHERE RECORDS HAVE BEEN KEPT SINCE 1964...THE LATEST
SNOWFALL WAS .5 INCHES ON MAY 5TH OF 1973.

HERE IN STATE COLLEGE RECORDS EXIST FROM 1925. THE LATEST SNOWFALL
WAS .2 INCHES ON MAY 9TH OF 1947.

IN SOMERSET RECORDS HAVE BEEN KEPT SINCE 1948. THEY OBSERVED .1
INCHES OF SNOW ON MAY 1ST OF 1963.

AN INCH OF NEW SNOW WAS ACTUALLY MEASURED TODAY BY OUR COOPERATIVE
WEATHER OBSERVER IN PHILIPSBURG...HOWEVER RECORDS HAVE ONLY BEEN
KEPT THERE SINCE 1986. WITH THIS SHORT PERIOD OF RECORD...THIS MAKES
IT THE FIRST TIME SNOW HAS EVER BEEN OFFICIALLY MEASURED IN MAY.

WHILE WE SHIVER UNDER A CHILLY RAIN WITH THE TEMPERATURE MORE THAN
20 DEGREES BELOW NORMAL TODAY...FEAR NOT BECAUSE THE UNUSUAL LATE
TASTE OF WINTER IS ONLY TEMPORARY. WITH SUNSHINE RETURNING FOR
TUESDAY AND WEDNESDAY...THE HIGH TEMPERATURE WILL RETURN TO
NORMAL FOR THE SECOND WEEK OF MAY...NEARING OR EXCEEDING 70
DEGREES IN MOST AREAS.



$$

LA CORTE

So what's the toughest event at the Olympic Games ?

You had to ask.

:-) 

CLICK HERE

"as electronic technologies...become more sophisticated and more embedded into everyday life, they have also become more vulnerable to solar activity."

 

"potential damage to the 900-plus satellites currently in orbit could cost between $30 billion and $70 billion."

"Humans in space would be in peril, too."

 

This is a great article that came out yesterday.

---- David

____________________________

May 6, 2008: At 11:18 AM on the cloudless morning of Thursday, September 1, 1859, 33-year-old Richard Carrington—widely acknowledged to be one of England's foremost solar astronomers—was in his well-appointed private observatory. Just as usual on every sunny day, his telescope was projecting an 11-inch-wide image of the sun on a screen, and Carrington skillfully drew the sunspots he saw.

Right: Sunspots sketched by Richard Carrington on Sept. 1, 1859. Copyright: Royal Astronomical Society: more.

On that morning, he was capturing the likeness of an enormous group of sunspots. Suddenly, before his eyes, two brilliant beads of blinding white light appeared over the sunspots, intensified rapidly, and became kidney-shaped. Realizing that he was witnessing something unprecedented and "being somewhat flurried by the surprise," Carrington later wrote, "I hastily ran to call someone to witness the exhibition with me. On returning within 60 seconds, I was mortified to find that it was already much changed and enfeebled." He and his witness watched the white spots contract to mere pinpoints and disappear.

It was 11:23 AM. Only five minutes had passed.

Just before dawn the next day, skies all over planet Earth erupted in red, green, and purple auroras so brilliant that newspapers could be read as easily as in daylight. Indeed, stunning auroras pulsated even at near tropical latitudes over Cuba, the Bahamas, Jamaica, El Salvador, and Hawaii.

Even more disconcerting, telegraph systems worldwide went haywire. Spark discharges shocked telegraph operators and set the telegraph paper on fire. Even when telegraphers disconnected the batteries powering the lines, aurora-induced electric currents in the wires still allowed messages to be transmitted.

"What Carrington saw was a white-light solar flare—a magnetic explosion on the sun," explains David Hathaway, solar physics team lead at NASA's Marshall Space Flight Center in Huntsville, Alabama.

Now we know that solar flares happen frequently, especially during solar sunspot maximum. Most betray their existence by releasing X-rays (recorded by X-ray telescopes in space) and radio noise (recorded by radio telescopes in space and on Earth). In Carrington's day, however, there were no X-ray satellites or radio telescopes. No one knew flares existed until that September morning when one super-flare produced enough light to rival the brightness of the sun itself.

"It's rare that one can actually see the brightening of the solar surface," says Hathaway. "It takes a lot of energy to heat up the surface of the sun!"

Above: A modern solar flare recorded Dec. 5, 2006, by the X-ray Imager onboard NOAA's GOES-13 satellite. The flare was so intense, it actually damaged the instrument that took the picture. Researchers believe Carrington's flare was much more energetic than this one.

The explosion produced not only a surge of visible light but also a mammoth cloud of charged particles and detached magnetic loops—a "CME"—and hurled that cloud directly toward Earth. The next morning when the CME arrived, it crashed into Earth's magnetic field, causing the global bubble of magnetism that surrounds our planet to shake and quiver. Researchers call this a "geomagnetic storm." Rapidly moving fields induced enormous electric currents that surged through telegraph lines and disrupted communications.

"More than 35 years ago, I began drawing the attention of the space physics community to the 1859 flare and its impact on telecommunications," says Louis J. Lanzerotti, retired Distinguished Member of Technical Staff at Bell Laboratories and current editor of the journal Space Weather. He became aware of the effects of solar geomagnetic storms on terrestrial communications when a huge solar flare on August 4, 1972, knocked out long-distance telephone communication across Illinois. That event, in fact, caused AT&T to redesign its power system for transatlantic cables. A similar flare on March 13, 1989, provoked geomagnetic storms that disrupted electric power transmission from the Hydro Québec generating station in Canada, blacking out most of the province and plunging 6 million people into darkness for 9 hours; aurora-induced power surges even melted power transformers in New Jersey. In December 2005, X-rays from another solar storm disrupted satellite-to-ground communications and Global Positioning System (GPS) navigation signals for about 10 minutes. That may not sound like much, but as Lanzerotti noted, "I would not have wanted to be on a commercial airplane being guided in for a landing by GPS or on a ship being docked by GPS during that 10 minutes."

Right: Power transformers damaged by the March 13, 1989, geomagnetic storm: more.

Another Carrington-class flare would dwarf these events. Fortunately, says Hathaway, they appear to be rare:

"In the 160-year record of geomagnetic storms, the Carrington event is the biggest." It's possible to delve back even farther in time by examining arctic ice. "Energetic particles leave a record in nitrates in ice cores," he explains. "Here again the Carrington event sticks out as the biggest in 500 years and nearly twice as big as the runner-up."

These statistics suggest that Carrington flares are once in a half-millennium events. The statistics are far from solid, however, and Hathaway cautions that we don't understand flares well enough to rule out a repeat in our lifetime.

And what then?

Lanzerotti points out that as electronic technologies have become more sophisticated and more embedded into everyday life, they have also become more vulnerable to solar activity. On Earth, power lines and long-distance telephone cables might be affected by auroral currents, as happened in 1989. Radar, cell phone communications, and GPS receivers could be disrupted by solar radio noise. Experts who have studied the question say there is little to be done to protect satellites from a Carrington-class flare. In fact, a recent paper estimates potential damage to the 900-plus satellites currently in orbit could cost between $30 billion and $70 billion. The best solution, they say: have a pipeline of comsats ready for launch.

Humans in space would be in peril, too. Spacewalking astronauts might have only minutes after the first flash of light to find shelter from energetic solar particles following close on the heels of those initial photons. Their spacecraft would probably have adequate shielding; the key would be getting inside in time.

No wonder NASA and other space agencies around the world have made the study and prediction of flares a priority. Right now a fleet of spacecraft is monitoring the sun, gathering data on flares big and small that may eventually reveal what triggers the explosions. SOHO, Hinode, STEREO, ACE and others are already in orbit while new spacecraft such as the Solar Dynamics Observatory are readying for launch.

Research won't prevent another Carrington flare, but it may make the "flurry of surprise" a thing of the past.

 

Authors: Trudy Bell & Dr. Tony Phillips | Editor: Dr. Tony Phillips | Credit: Science@NASA

A volcano erupts in Chile.

Check out the NASA pictures from space.

 

CLICK HERE

 

Courtesy:  NASA

Over 10,000 people (and counting) are believed to have died from this storm.

Here are the NASA pictures BEFORE and AFTER the Cyclone.

CLICK HERE




Courtesy:  NASA

April 30, 2008: Today, NASA-funded researchers released to the general public a new "4D" live model of Earth's ionosphere. Without leaving home, anyone can fly through the layer of ionized gas that encircles Earth at the edge of space itself. All that's required is a connection to the Internet.

"This is an exciting development," says solar physicist Lika Guhathakurta of NASA headquarters in Washington, DC. "The ionosphere is important to pilots, ham radio operators, earth scientists and even soldiers. Using this new 4D tool, they can monitor and study the ionosphere as if they're actually inside it."

Click on the screenshot to view a 19 MB video demo:

Above: A screen-shot of the 4D ionosphere. Clicking on the image launches a 19 MB video demo. You can download and launch your own 4D ionosphere by following these simple instructions.

The ionosphere is, in a sense, our planet's final frontier. It is the last wisp of Earth's atmosphere that astronauts leave behind when they enter space. The realm of the ionosphere stretches from 50 to 500 miles above Earth's surface where the atmosphere thins to near-vacuum and exposes itself to the fury of the sun. Solar ultraviolet radiation breaks apart molecules and atoms creating a globe-straddling haze of electrons and ions.

Ham radio operators know the ionosphere well. They can communicate over the horizon by bouncing their signals off of the ionosphere—or communicate not at all when a solar flare blasts the ionosphere with X-rays and triggers a radio blackout. The ionosphere also has a big impact on GPS reception. Before a GPS satellite signal reaches the ground, it must first pass through ionospheric gases that bend, reflect and attenuate radio waves. Solar and geomagnetic storms that unsettle the ionosphere can cause GPS position errors as large as 100 meters. Imagine a pilot flying on instruments descending toward a landing strip only to discover it is a football field to the right.

"Understanding the ionosphere is clearly important. That's why NASA's Living with a Star (LWS) program funded this work," says Guhathakurta, LWS program scientist. Space Environment Technologies, Inc. of California received the LWS grant and they partnered with Space Environment Corp. of Utah and the US Air Force to develop the 4D ionosphere.

"The best way to appreciate the 4D ionosphere is to try it," says W. Kent Tobiska, president of Space Environment Technologies and chief scientist of its Space Weather Division. He offers these instructions:

"One, download and install Google Earth."

"Two, visit our web site and click on the link 'Total Electron Content.'"

Right: Kent Tobiska demonstrates the use of the 4D Ionosphere: 19 MB video.

Wait for the file to load and presto—you're flying through the ionosphere: screenshot.

"Colors represent electron content," Tobiska explains. "Bright red is high density; that's where radio communications are restricted to few or no frequencies. Blue denotes low density; no problem there."

Using the intuitive Google Earth interface, users can fly above, around and through these regions getting a true 3D view of the situation. Make that 4D. "The fourth dimension is time. This is a real-time system updated every 10 minutes," he says.

The 4D model can be fun and even a little addictive, warns Tobiska, who likes to use it to pilot an imaginary plane over the Arctic. "A growing number of commercial business flights are crossing the Arctic Circle," he says. "It's the shortest distance between, say, Chicago and Beijing and many other major cities."

Below: An increasing number of international business flights cross Earth's Arctic to save time, fuel and money. [Larger image]

The ionosphere is particularly important to these lucrative flights. While they are over the Arctic, planes lose contact with most geosynchronous satellites and must rely on "old-fashioned" radio communications—a link that could be severed during a radio blackout. Using the 4D model, a flight controller could examine the ionosphere from the flyer's point of view and use that information to anticipate problems that could cause a flight to be delayed or diverted.

The proper name of the system is CAPS, short for Communication Alert and Prediction System. Earth-orbiting satellites feed the system up-to-the-minute information on solar activity; the measurements are then converted to electron densities by physics-based computer codes. It is important to note, says Tobiska, that CAPS reveals the ionosphere not only as it is now, but also as it is going to be the near future. "Forecasting is a key aspect of CAPS available to our customers from, e.g., the Dept. of Defense and the airline industry."

Start your own flight here.

Author: Dr. Tony Phillips | Editor: Dr. Tony Phillips | Credit: Science@NASA

"IPCC researchers project no global warming over the next decade because of Mother Nature."

Did you catch that ?  Read more.

 

CLICK HERE

"Is This Right ?  Is This Fair ?"

These questions are often asked in the world of politics, criminal justice and even religion.

So why not in the world of global warming ?

 

CLICK HERE for the article.

 

Should the world renowned hurricane expert Dr. William Gray be silenced for being a global warming skeptic ?

I think not. 

What's your opinion ?  Is there more to this than meets the eye ?

CLICK HERE


"Every day is Earth Day on the International Space Station."

It runs a lap every hour and a half and maintains a cool 17,500 mph.

Kinda cool, eh ? 

----David

"April Showers Bring May Flowers"

or so the saying goes.

 

Looking back at the National Weather Service data for RAINFALL, here is what I found for the City of Philadelphia...

 

9.05 inches  Last April 2007  

(Some of it, SLEET)

 

1.19 inches so far...    April 2008

 

3.49 inches NORMAL FOR THE MONTH 

 

Next Chance of Rain ?  This Weekend.

Keep watering your GRASS SEED. 

Allergy sufferers take note:

Tree pollen will remain high with very little relief until we get some showers to "cleanse" the atmosphere temporarily.   

"April 21, 2008: At this year's Great Moonbuggy Race in Huntsville, Alabama, Prof. Paul Shiue of Christian Brothers University was overheard joking that duct tape was his team's "best engineering tool." Others felt the same way. The sound of gray tape being torn from rolls practically filled the race course as dozens of college and high school student engineers busily assembled and repaired their homemade moonbuggies.

Little did they know, this was in the finest tradition of lunar exploration. Turning back the clock 36 years reveals the key roll of duct tape in NASA's Apollo program:

The date was Dec. 11, 1972. Astronauts Gene Cernan and Jack Schmitt had just landed their lunar module Challenger in a beautiful mountain-ringed valley named Taurus-Littrow on the edge of the Sea of Serenity. Mission planners chose the site for its geological variety: the ground was covered by a mix of giant boulders, hardened lava, orange glass beads (a sign of ancient volcanic fire fountains) and, of course, ubiquitous moondust. The valley itself was a fracture created in the aftermath of an asteroid impact billions of years ago; the history of the Moon, many suspected, might be written along its walls. Jack Schmitt, the first geologist on the Moon, could hardly wait to get started.

Above: Apollo 17 astronauts and moonbuggy in the Taurus-Littrow valley. [More]

About 60 seconds after touchdown, Schmitt radioed Houston, "Batteries look good," followed by a brief pause, and "Oh, man!! Look at that rock out there!"

Cernan agreed, "Absolutely incredible."

Within hours the two astronauts were down the ladder loading a raft of geology tools and experiments onto their Lunar Roving Vehicle or "moonbuggy." Everything was going smoothly until Cernan brushed against the rover; a hammer in the shin pocket of his spacesuit caught the buggy's right rear fender and tore half of it off.

Cernan: "Oh, you won't believe it. There goes a fender."

Schmitt: "Oh, shoot!"

Now, a moonbuggy in Alabama can go just fine without a fender, but in Taurus-Littrow a missing fender was a potential disaster. The reason is moondust. When a rover rolls across the lunar surface, it kicks up a plume of moondust in its wake. (Astronauts called them "rooster tails.") Without a fender, the rover would be showered by a spray of dark, abrasive grit. White spacesuits blackened by dust could turn into dangerous absorbers of the fierce lunar sun with astronauts overheating inside. Sharp-edged dust wiped off visors would scratch the glass, making helmets difficult to see out of. Moondust also had an uncanny way of working itself into hinges, latches and joints, rendering them useless.

Above: Apollo 17 moonbuggy fender repaired with duct tape.

Cernan: "And I hate to say it, but I'm going to have to take some time to try … to get that fender back on. Jack, is the tape under my seat, do you remember?" (He's referring to a roll of ordinary, gray duct tape.)

Schmitt: "Yes."

Cernan: "Okay. I can't say I'm very adept at putting fenders back on. But I sure don't want to start without it. I'm just going to put a couple of pieces of good old-fashioned American gray tape on it...(and) see whether we can't make sure it stays."

In spite of his thick gloves, Cernan managed to unroll and tear off the needed pieces, but moondust foiled his first repair:

Cernan: "…good old-fashioned gray tape doesn't want to stick very well." (At a post flight briefing he explained: "Because there was dust on everything, once you got a piece of tape off the roll, the first thing the tape stuck to was dust; and then it didn't stick to anything else.")

His second attempt succeeded, however. "I am done!" crowed Cernan. "If that fender stays on ... I'd like some sort of mending award." And with that, they were off.

For the next four hours they drove the moonbuggy far and wide around the landing site, stopping to drill holes and collect core samples, deploy seismic charges and set up other experiments. Even with all four fenders, Cernan had to dust off the rover at each stop (mission planners provided a special moondust brush for the purpose). This soaked up many minutes of valuable time, but could've been worse as they were about to discover.

Right: Gene Cernan works with his roll of duct tape. Click to view a longer movie with sound.

Driving across a rough patch of lunar terrain, Cernan commented, "Man, you could lose the rear end of this thing in a hurry." And, indeed, the fender fell off again. Duct tape held it for a while, but moondust had reduced the tape's stickiness too much to hold on for a whole EVA (Extra-Vehicular Activity).

Schmitt: "I think you have lost your fender. I keep getting rained on here (with lunar dust)."

Cernan: "Oh, no!"

Schmitt: "Look at our rooster tail."

Subsequent stops required considerable housekeeping. "Let me run around and dust!" radioed Cernan while Schmitt deployed the Surface Electrical Properties (SEP) experiment. In a post-flight briefing he noted, "The dust on the battery covers and everything else was thick enough to write in. With a working fender you'd always got a light film of dust; but this was 'dirt' dust."

Back at the Challenger, Cernan gave the parked rover a rueful inspection. "Oh, man, I tell you, it's going to take us half a dozen Sundays to dust. Look at that fender; that's terrible. Boy, that one fender just [creates] an order of magnitude more of a dust problem."

Back in Houston, NASA engineers understood the seriousness of the situation. If they couldn't come up with a solution while Cernan and Schmitt slept, the next day's exploration could be severely curtailed. The astronauts might even be limited to walking distance.

Right: Gene Cernan, back in the lunar lander after a long EVA. The smudges on his forehead and longjohns are moondust. Photo credit: Jack Schmitt. [More]

But they did come up with a fix and it called on, you guessed it, duct tape.

When Cernan and Schmitt woke up the next morning, mission control explained how they should tape four laminated maps together in the shape of the missing fender. "Just call me the little old fender maker," said Cernan as he tore off pieces of gray tape. This time the taping was done inside the relatively dust-free confines of the lunar lander, so the duct tape retained its usual stickiness. Clamped to the moonbuggy, the new fender held for the rest of the mission, which included another 15 hours of EVAs.

One dousing with dust was enough to make a deep impression on Schmitt. Back on Earth he opined that "the dust issue is one that just has to be addressed. It's going to be the major environmental issue for future missions to the Moon."

Back to the future: Right now, NASA is preparing a return to the Moon and dust is very much on the agency's mind. NASA scientists are doing laboratory experiments with samples of Apollo moondust to discover techniques for "moondust mitigation." And a new NASA spacecraft named LADEE is devoted entirely to moondust. Short for Lunar Atmosphere and Dust Environment Explorer, LADEE will orbit the moon in 2011 or 2012 watching for "dust storms" thought to occur when electrostatically charged moondust levitates off the lunar surface.

When next-generation astronauts go to the Moon, they'll know a lot more about moondust than their Apollo predecessors. But you can bet there’s one thing they won’t leave home without—"good old-fashioned American gray tape."

Author: Dr. Tony Phillips | Credit: Science@NASA"

CLICK HERE

Tom Knudson

Dr. William Gray, Colorado State University

Dr. Steve Lyons, The Weather Channel

"Tom Knudson claims that the global climate models can be used to test theory (such as his claim on the dominance of CO2 as the driver of climate change).

However, Tom Knudson makes the very serious mistake of stating that models can test his claim. The models are hypotheses and cannot test anything! They can be used to improve our understanding of how a system works, but their results must be tested against real-world observational data."

CLICK HERE

Courtesy: www.icecap.us

April 17, 2008: 

"Behold the full Moon. Ancient craters and frozen lava seas lie motionless under an airless sky of profound quiet. It's a slow-motion world where even a human footprint may last millions of years. Nothing ever seems to happen there.

Right?

Wrong. NASA-supported scientists have realized that something does happen every month when the Moon gets a lashing from Earth's magnetic tail.

"Earth's magnetotail extends well beyond the orbit of the Moon and, once a month, the Moon orbits through it," says Tim Stubbs, a University of Maryland scientist working at the Goddard Space Flight Center. "This can have consequences ranging from lunar 'dust storms' to electrostatic discharges."

Above: The full Moon inside Earth's magnetic tail, March 2008.

Yes, Earth does have a magnetic tail. It is an extension of the same familiar magnetic field we experience when using a Boy Scout compass. Our entire planet is enveloped in a bubble of magnetism, which springs from a molten dynamo in Earth's core. Out in space, the solar wind presses against this bubble and stretches it, creating a long "magnetotail" in the downwind direction: diagram.

Anyone can tell when the Moon is inside the magnetotail. Just look: "If the Moon is full, it is inside the magnetotail," says Stubbs. "The Moon enters the magnetotail three days before it is full and takes about six days to cross and exit on the other side."

It is during those six days that strange things can happen.

During the crossing, the Moon comes in contact with a gigantic "plasma sheet" of hot charged particles trapped in the tail. The lightest and most mobile of these particles, electrons, pepper the Moon's surface and give the Moon a negative charge.

Right: The Moon's orbit crosses Earth's magnetotail. [Larger image]

On the Moon's dayside this effect is counteracted to a degree by sunlight: UV photons knock electrons back off the surface, keeping the build-up of charge at relatively low levels. But on the nightside, in the cold lunar dark, electrons accumulate and voltages can climb to hundreds or thousands of volts.

Walking across the dusty charged-up lunar terrain, astronauts may find themselves crackling with electricity like a sock pulled out of a hot dryer. Touching another astronaut, a doorknob, a piece of sensitive electronics—any of these simple actions could produce an unwelcome zap. "Proper grounding is strongly recommended," advises Stubbs.

The ground, meanwhile, may leap into the sky. There is compelling evidence (see, e.g., the Surveyor 7 image below) that fine particles of moondust, when sufficiently charged-up, actually float above the lunar surface. This could create a temporary nighttime atmosphere of dust ready to blacken spacesuits, clog machinery, scratch faceplates (moondust is very abrasive) and generally make life difficult for astronauts.

Stranger still, moondust might gather itself into a sort of diaphanous wind. Drawn by differences in global charge accumulation, floating dust would naturally fly from the strongly-negative nightside to the weakly-negative dayside. This "dust storm" effect would be strongest at the Moon's terminator, the dividing line between day and night.

Much of this is pure speculation, Stubbs cautions. No one can say for sure what happens on the Moon when the magnetotail hits, because no one has been there at the crucial time. "Apollo astronauts never landed on a full Moon and they never experienced the magnetotail."

The best direct evidence comes from NASA's Lunar Prospector spacecraft, which orbited the Moon in 1998-99 and monitored many magnetotail crossings. During some crossings, the spacecraft sensed big changes in the lunar nightside voltage, jumping "typically from -200 V to -1000 V," says Jasper Halekas of UC Berkeley who has been studying the decade-old data.

Above: In 1968, on many occasions, NASA's Surveyor 7 moon lander photographed a strange "horizon glow" after dark. Researchers now believe the glow is sunlight scattered from electrically-charged moondust floating just above the lunar surface.

"It is important to note," says Halekas, "that the plasma sheet (where all the electrons come from) is a very dynamic structure. The plasma sheet is in a constant state of motion, flapping up and down all the time. So as the Moon orbits through the magnetotail, the plasma sheet can sweep across it over and over again. Depending on how dynamic things are, we can encounter the plasma sheet many times during a single pass through the magnetotail with encounters lasting anywhere from minutes to hours or even days."

"As a result, you can imagine how dynamic the charging environment on the Moon is. The Moon can be just sitting there in a quiet region of the magnetotail and then suddenly all this hot plasma goes sweeping by causing the nightside potential to spike to a kilovolt. Then it drops back again just as quickly."

The roller coaster of charge would be at its most dizzying during solar and geomagnetic storms. "That is a very dynamic time for the plasma sheet and we need to study what happens then," he says.

What happens then? Next-generation astronauts are going to find out. NASA is returning to the Moon in the decades ahead and plans to establish an outpost for long-term lunar exploration. It turns out they'll be exploring the magnetotail, too."

Courtesy:  Dr. Tony Phillips and Science@NASA