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Freitag, 21. März 2014 - 09:20 Uhr

UFO-Forschung - IFO-Universität: Meteoriten und Wiedereintritte von Weltraummüll

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In this installment, I felt it was important to discuss meteors and satellite re-entries. These celestial events are often misinterpreted by observers and UFOlogists
alike. Recent entries by the UFO examiner of MUFON, indicate that even experienced UFOlogists seem to have a lack of knowledge on the subject.
Terminology
I have seen many people use the wrong terminology when discussing meteors. So, it is important to clarify a few terms.
A meteoroid is any small object that is in outer space up to the size of about a boulder. When a meteoroid enters the earth’s (or any other planet’s) atmosphere,
it becomes a meteor. If the meteoroid survives its passage through the atmosphere and strikes the earth, it is called a meteorite. Any meteor that is considered brighter than the planet Venus is considered a fireball. If the fireball becomes very bright (usually full moon or brighter), it is sometimes referred to as a bolide. These bright fireballs can possibly produce meteorites.
Light display
A common question I have been asked in the past is how can something the size of a grain of sand be so luminous that it can be seen from so far away. This has to do with the meteor’s interaction with the earth’s atmosphere. What is actually being seen is not only the meteoroid glowing but it’s interaction with the surrounding
atmosphere. The meteor’s passage excites the atoms of air molecules nearby and this causes them to glow.
Sometimes, a meteor can leave a persistent ion train. This looks like a brief smoke trail that rapidly disappears. In the case of bright fireballs, an ion trail can last for several minutes. 
Meteor colors
The color of a meteor has a lot to do with the composition of the meteoroid and the atmospheric molecules that are disturbed by its passage. If the meteoroid is large, the color of the meteor will probably be dominated by the meteor’s composition. However, if it is small, the composition of the meteor may have little  effect and the atmospheric molecules nearby will dominate the color of the meteor. Oxygen and Nitrogen molecules tend to give off a red color.
The Green fireballs and UFOs
Probably the most bizarre part of UFO folklore is the adventures of Lincoln LaPaz and the “Green fireball” phenomena of the late 1940s. LaPaz felt there was something unique about these objects because no meteorites were ever found and they were green in color. They also appeared to be confined to the southwest US but this may have been a case of people looking for them, while in the other parts of the US, there was little interest in doing so. The USAF was concerned because they, like UFOs, were seen as a potential threat/Soviet device. They spent some time and money trying to record these meteors on film with little success. Eventually, they lost interest in the matter but LaPaz continued to ponder
the problem many years later with no satisfactory results. The “green fireball” phenomenon has been linked to UFOlogy because of its unique nature and that some people felt they were not “natural meteors”. There never was any evidence presented to rule out these observations as nothing more than bright fireballs that were just green in appearance.
For some reason, when somebody now reports a “green fireball”, UFOlogy likes to refer to as a UFO, when it is more likely they just saw a bright green meteor. A good example of a “Green fireball” is the Peekskill fireball/meteorite fall of October 9th, 1992. It was recorded by many people on video tape (some sources list a total of 16 independent recordings including a football game) and was as bright (if not brighter) than the full moon. Its primary color was most definitely green but it was just an ordinary fireball meteor. This was demonstrated by it producing at least one meteorite that struck a parked car. Therefore, just because a fireball is “green” does not mean it qualifies as a UFO or that it is something so exotic as to dismiss it as just a bright meteor.
UFOs or plane crashes
The potential for a fireball to be misidentified as something else is well known. All one has to do is read the UFO reports associated with known fireball events. Many of the comments show the witnesses stating it could not be a meteor for various reasons. The problem is that many observers have never seen a bright fireball before. An ordinary meteor does not appear the same as a bright fireball. I still remember my first. It was a -8 bolide that lit up the ground when I was a young astronomer at Lyrid meteor watch. It left an ion trail that lasted several minutes.
Another comment in these UFO reports is that the meteor looked like a crashing aircraft and it will sometimes be reported as such. If the meteor breaks up and lasts long enough, witnesses may produce reports of a cigar shaped craft with windows.
A good example is the fireball of November 16, 1999. This appears to have been an earth-grazing meteor that lasted 10-20 seconds. The witness reports in the NUFORC database are most interesting:
It first apeared like a large plane with a row of windows. I thought it was a plane atempting to land on the highway. As it grew closer i realized the object was to large to be a plane. In addition it had no flashing lights or landing lights. It was very long in length, possibly 200’ to 500’ feet. It had a row of what apeared to be windows yellow orange in color, with several lights in the front and rear the same color. It seamed to slow as it got closer to my truck, almost directly in front, about 1/4 mile away. It dipped down behind some trees, and dissapeared.
Does this kind of report sound familiar? You may recall me referring to the Zond IV incident in SUNlite 2-3. In that case it was re-entering space debris. This demonstrates
that fireballs can produce the same effects. One can easily see the similarities between this fireball observation and the famous “Chiles-Whitted” event in July 1948.
Space debris re-entries
An event very similar to fireballs and bolides are satellite/booster rocket re-entries. These enter the earth’s atmosphere at much lower speeds and, as a result, they last a lot longer than meteors. While meteors rarely last longer than ten seconds, a satellite re-entry can last for tens of seconds. Because of the nature of these re-entries, there are usually are described as a formation of lights/streaks or one dark object with lights just like in the Zond IV case.
On the 14th of November 1997, there was a display put on by a Russian booster rocket re-entry it the northwest United States. Like Zond IV, a significant percentage
of the witnesses, who submitted reports to the National UFO reporting center (NUFORC), reported a large dark shape behind the lights. They were deceived by the “airship effect” just like the November 16, 1999 fireball.
A large, well lit flying wedged shaped object flying very low over my house without any noise...There were many lights outlining the wedge shape. They seemed to be about the same brightness although some appeared to be reddish while others blue. 2
Daylight fireballs
These are rare but do happen. The August 10, 1972 fireball is a good example but a more recent case is the July 23, 2001 event in Pennsylvania. The fireball was estimated at a magnitude of -20 to -26 (almost as bright as the sun) and was photographed by at least one observer. Most of the UFO reports in the NUFORC database referred to it as a fireball or “egg-shaped object”. There were a few who stated they saw it as a triangle or V-shaped object.
Data analysis
Curious, I decided to wade into the NUFORC database to see how many could have been caused by fireballs. I used the time period of July 10 to September 27 (for the years 2005-2008). This was chosen because this was when the most people would be out and it was after the fourth of July weekend when fireworks might create UFO reports that sound like meteors. There were a total of 4444 reports (by my count, which may be in error)! I initially started by examining the reports for short duration UFOs (<1 min) that sounded like meteors. I tried to avoid reports that might be Iridium flares or indicated motion that was too exotic to be a meteor. This produced a total of 431 potential fireball reports. I then decided to compare the 4444 reports with the American Meteor Society’s database of fireball reports. I received a surprise when a looked at my results. I counted 184 fireball identifications. Some observations from this data revealed:
Potential fireball reports made up about 10% of all the UFO reports filed. This is fairly consistent with Hendry’s data of around 9% (Number of meteors/total UFO reports of 1307)
The AMS table had a more limited scope since it involved fireball report made by a small sample of observers, who were only observing in a limited number of areas and not always during bright moon periods. The matching of their data with the NUFORC database revealed about a 4% success rate in identifying UFOs. This does not mean that the remaining 6% were not fireballs. It just means that the 6% were not observed by the AMS observers to make an accurate determination.
Some reports that I would have dis missed as not being a fireball (due to duration and details in the observation) turned out to be observations of bright fireballs.
Some bright fireballs observed by 4. AMS observer did not generate any UFO reports. That may have to do with the time of night or that UFO reporters recognized them as meteors.
Fireballs misperceived
Looking at the NUFORC reports that I identified as bright fireballs from the AMS data, I learned that some witnesses can misinterpret what they saw with all sorts of misperceived characteristics. Many will declare it could not have been a meteor because they know what one looks like. The problem is each fireball is unique and create effects that the observer may or may not be familiar with. Nobody seems to be immune to misperceiving these effects or thinking the fireball they saw was something exotic and not a meteor.
Quelle: SUNlite 5/2010

Tags: UFO-Forschung 

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Freitag, 21. März 2014 - 08:30 Uhr

Astronomie - Saturn-Mond Titan: Erste Hinweise von Wellen auf Meere

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The Cassini spacecraft has spotted what seem to be tiny waves on the seas of Titan.

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After years of searching, planetary scientists think they may finally have spotted waves rippling on the seas of Titan, Saturn’s largest moon. If confirmed, this would be the first discovery of ocean waves beyond Earth.
NASA’s Cassini spacecraft spied several unusual glints of sunlight off the surface of Punga Mare, one of Titan’s hydrocarbon seas, in 2012 and 2013. Those reflections may come from tiny ripples, no more than 2 centimetres high, that are disturbing the otherwise flat ocean, says Jason Barnes, a planetary scientist at the University of Idaho in Moscow.
Barnes presented the findings today at the Lunar and Planetary Science Conference, where a second talk hinted at the presence of waves in another of Titan’s seas.
Researchers expect more waves to appear in the next few years, because winds are anticipated to pick up as Titan’s northern hemisphere — where most of its seas are located — emerges from winter and approaches spring.
“Titan may be beginning to stir,” says Ralph Lorenz, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. “Oceanography is no longer just an Earth science.”
On its many flights past Titan, Cassini discovered small lakes and large seas of methane, ethane and other hydrocarbon compounds1. Liquid rains down on the moon’s surface and then evaporates, setting up a complex weather system that includes, presumably, wind patterns.
But the probe had never spotted wind rippling the surface of Titan’s seas. They seemed as smooth as glass. That could be because the liquid hydrocarbons are more viscous than water and thus harder to get moving, or because the winds on Titan are simply not strong enough to blow the liquid into ripples. In 2010, Lorenz and others proposed that the winds would strengthen as Titan moved towards spring, allowing scientists a better chance to spot waves2. Saturn and its moons take about 29 Earth years to go around the Sun.
Four bright pixels
A spectrometer aboard Cassini took images of Punga Mare as the spacecraft flew past it several times during 2012 and 2013. Those images showed sunlight glinting off the ocean’s surface, as might be seen on Earth when an aeroplane flies low over a lake at dusk.
Four pixels in the images are brighter than one might expect from reflecting sunlight, Barnes reported at the conference. He concluded that they must represent something particularly rough on the surface — a wave or set of waves.
Calculations of the waves’ height suggested they were a puny few centimetres high. “Don’t make your surfing plane reservation for Titan just yet,” Barnes told the conference.
Knowing how the waves form will help scientists to better understand the physical conditions in Titan’s lakes and seas3. A NASA mission proposal, which was beaten by a proposal to return to Mars, would have sent a probe to float in one of Titan’s lakes. “If we drop a lake lander in there, is it going to splat instead of splash?” asks Barnes.
There is still a chance that Cassini is seeing reflections off a wet, solid surface, such as a mudflat, rather than actual waves. Future observations might spot the waves of Punga Mare again, but Barnes says that there is no guarantee that Cassini will pass by in the right position before the end of its mission, a planned plunge into Saturn in 2017.
A second report at the conference also hints at possible waves. Last summer, Cassini scientists spotted what they called a ‘magic island’ in another sea, Ligeia Mare, that appeared and then disappeared. It looked like a bright reflection in one image but was not visible 16 days later or in any photographs taken since, said Jason Hofgartner, a planetary scientist at Cornell University in Ithaca, New York.
After ruling out possibilities such as an island exposed by a change in sea level, the team concluded that the ‘magic island’ is probably a set of waves, a group of bubbles rising from below the surface or a suspended mass, such as an iceberg.
The Ligeia Mare researchers may have better luck than Barnes and his colleagues — a Cassini fly-by in August should be able to image this particular area of Ligeia Mare and hunt for waves again.
Quelle: nature
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Update: 21.03.2014
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Surface of Titan Sea is mirror smooth, Stanford scientists find

This false-color image of the surface of Titan was made using radar measurements made by NASA's Cassini spacecraft. The spacecraft revealed that the surface of Ligeia Mare, Titan's second largest lake, is unusually still, most likely due to a lack of winds at the time of observation.
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New radar measurements of an enormous sea on Titan offer insights into the weather patterns and landscape composition of the Saturnian moon. The measurements, made in 2013 by NASA's Cassini spacecraft, reveal that the surface of Ligeia Mare, Titan's second largest sea, possesses a mirror-like smoothness, possibly due to a lack of winds.
"If you could look out on this sea, it would be really still. It would just be a totally glassy surface," said Howard Zebker, professor of geophysics and of electrical engineering at Stanford who is the lead author of a new study detailing the research.
The findings, recently published online in Geophysical Research Letters, also indicate that the solid terrain surrounding the sea is likely made of solid organic materials and not frozen water.
Saturn's second largest moon, Titan has a dense, planet-like atmosphere and large seas made of methane and ethane. Measuring roughly 260 miles (420 km) by 217 miles (350 km), Ligeia Mare is larger than Lake Superior on Earth. "Titan is the best analog that we have in the solar system to a body like the Earth because it is the only other body that we know of that has a complex cycle of solid, liquid, and gas constituents," Zebker said.
Titan's thick cloud cover makes it difficult for Cassini to obtain clear optical images of its surface, so scientists must rely on radar, which can see through the clouds, instead of a camera.
To paint a radar picture of Ligeia Mare, Cassini bounced radio waves off the sea's surface and then analyzed the echo. The strength of the reflected signal indicated how much wave action was happening on the sea. To understand why, Zebker said, imagine sunlight reflecting off of a lake on Earth. "If the lake were really flat, it would act as a perfect mirror and you would have an extremely bright image of the sun," he said. "But if you ruffle up the surface of the sea, the light gets scattered in a lot of directions, and the reflection would be much dimmer. We did the same thing with radar on Titan."
The radar measurements suggest the surface of Ligeia Mare is eerily still. "Cassini's radar sensitivity in this experiment is one millimeter, so that means if there are waves on Ligeia Mare, they're smaller than one millimeter. That's really, really smooth," Zebker said.
One possible explanation for the sea's calmness is that no winds happened to be blowing across that region of the moon when Cassini made its flyby. Another possibility is that a thin layer of some material is suppressing wave action. "For example, on Earth, if you put oil on top of a sea, you suppress a lot of small waves," Zebker said.
Cassini also measured microwave radiation emitted by the materials that make up Titan's surface. By analyzing those measurements, and accounting for factors such as temperature and pressure, Zebker's team confirmed previous findings that the terrain around Ligeia Mare is composed of solid organic material, likely the same methane and ethane that make up the sea. "Like water on Earth, methane on Titan can exists as a solid, a liquid, and a gas all at once," Zebker said.
Titan's similarities to Earth make it a good model for our own planet's early evolution, Zebker said. "Titan is different in the details from Earth, but because there is global circulation happening, the big picture is the same," he added. "Seeing something in two very different environments could help reveal the overall guiding principles for the evolution of planetary bodies, and help explain why Earth developed life and Titan didn't."
Quelle: EurekAlert
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Cassini VIMS image showing specular reflections in one of Titan’s many lakes during the T85 flyby on July 24, 2012.
Quelle: NASA

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Freitag, 21. März 2014 - 08:03 Uhr

Astronomie - Spitzer-Teleskop der NASA bringt 360-Grad-Ansicht der Galaxie zu unseren Fingerspitzen

GLIMPSE the Galaxy All the Way Around
When you look up at the Milky Way on a clear, dark night, you'll see a band of bright stars arching overhead. This is the plane of our flat spiral galaxy, within which our solar system lies.
A new, zoomable panorama from NASA's Spitzer Space Telescope shows us our galaxy's plane all the way around us in infrared light. The 360-degree mosaic comes primarily from the GLIMPSE360 project, which stands for Galactic Legacy Infrared Mid-Plane Survey Extraordinaire. It consists of more than 2 million snapshots taken in infrared light over 10 years, beginning in 2003 when Spitzer launched.
The Milky Way diagrams to the right of the panels show what slice of the galaxy is being seen. The center of the galaxy was the most widely covered and is shown in the second row. The outer regions of our galaxy, away from its bustling center, are in the last three rows.
This infrared view reveals much more of the galaxy than can be seen in visible-light views. Whereas visible light is blocked by dust, infrared light from stars and other objects can travel through dust to reach Spitzer's detectors. For instance, when looking up at our night skies, we see stars that are an average of 1,000 light-years away; the rest are hidden. In Spitzer's mosaic, light from stars throughout the galaxy -- which stretches 100,000 light-years across -- shines through. This picture covers only about three percent of the sky, but includes more than half of the galaxy's stars and the majority of its star formation activity.
The red color shows dusty areas of star formation. Throughout the galaxy, tendrils, bubbles and sculpted dust structures are apparent. These are the results of massive stars blasting out winds and radiation. Stellar clusters deeply embedded in gas and dust, green jets and other features related to the formation of young stars can also be seen for the first time. Looking toward the galactic center, the blue haze is made up of starlight -- the region is too far away for us to pick out individual stars, but they contribute to the glow. Dark filaments that show up in stark contrast to the bright background are areas of thick, cold dust that not even infrared light can penetrate. If you look closely, it's even possible to spot distant galaxies that lie far beyond the Milky Way.
Scientists are using these images to get to know our galaxy better. They've come up with better maps of its central bar of stars and spiral structure, discovered new remote sites of star formation and even come across new mysteries; for example, the dust grains indicate a higher abundance of carbon in the galaxy than expected. The GLIMPSE360 map will guide astronomers for generations, helping them to further chart the unexplored territories of our own Milky Way.
The image combines data from multiple surveys in addition to GLIMPSE360: GLIMPSE, GLIMPSEII, GLIMPSE3D, Vela-Carina, Deep GLIMPSE, CYGX, GALCEN and SMOG. Twelve-micron data from NASA's Wide-field Infrared Survey Explorer (WISE) was substituted for missing 8-micron data in outer galaxy regions mapped during Spitzer’s post-cryogen mission.
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Touring the Milky Way now is as easy as clicking a button with NASA's new zoomable, 360-degree mosaic presented Thursday at the TEDActive 2014 Conference in Vancouver, Canada.
The star-studded panorama of our galaxy is constructed from more than 2 million infrared snapshots taken over the past 10 years by NASA's Spitzer Space Telescope.
"If we actually printed this out, we'd need a billboard as big as the Rose Bowl Stadium to display it," said Robert Hurt, an imaging specialist at NASA's Spitzer Space Science Center in Pasadena, Calif. "Instead we’ve created a digital viewer that anyone, even astronomers, can use."
The 20-gigapixel mosaic uses Microsoft’s WorldWide Telescope visualization platform. It captures about three percent of our sky, but because it focuses on a band around Earth where the plane of the Milky Way lies, it shows more than half of all the galaxy's stars.
The image, derived primarily from the Galactic Legacy Mid-Plane Survey Extraordinaire project, or GLIMPSE360, is online at:
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Spitzer, launched into space in 2003, has spent more than 10 years studying everything from asteroids in our solar system to the most remote galaxies at the edge of the observable universe. In this time, it has spent a total of 4,142 hours (172 days) taking pictures of the disk, or plane, of our Milky Way galaxy in infrared light. This is the first time those images have been stitched together into a single expansive view.
Our galaxy is a flat spiral disk; our solar system sits in the outer one-third of the Milky Way, in one of its spiral arms. When we look toward the center of our galaxy, we see a crowded, dusty region jam-packed with stars. Visible-light telescopes cannot look as far into this region because the amount of dust increases with distance, blocking visible starlight. Infrared light, however, travels through the dust and allows Spitzer to view past the galaxy's center.
"Spitzer is helping us determine where the edge of the galaxy lies," said Ed Churchwell, co-leader of the GLIMPSE team at the University of Wisconsin-Madison. "We are mapping the placement of the spiral arms and tracing the shape of the galaxy."
Using GLIMPSE data, astronomers have created the most accurate map of the large central bar of stars that marks the center of the galaxy, revealing the bar to be slightly larger than previously thought. GLIMPSE images have also shown a galaxy riddled with bubbles. These bubble structures are cavities around massive stars, which blast wind and radiation into their surroundings.
All together, the data allow scientists to build a more global model of stars, and star formation in the galaxy -- what some call the "pulse" of the Milky Way. Spitzer can see faint stars in the "backcountry" of our galaxy -- the outer, darker regions that went largely unexplored before.
"There are a whole lot more lower-mass stars seen now with Spitzer on a large scale, allowing for a grand study," said Barbara Whitney of the University of Wisconsin, Madison, co-leader of the GLIMPSE team. "Spitzer is sensitive enough to pick these up and light up the entire 'countryside' with star formation."
The Spitzer team previously released an image compilation showing 130 degrees of our galaxy, focused on its hub. The new 360-degree view will guide NASA's upcoming James Webb Space Telescope to the most interesting sites of star-formation, where it will make even more detailed infrared observations.
Some sections of the GLIMPSE mosaic include longer-wavelength data from NASA's Wide-field Infrared Survey Explorer, or WISE, which scanned the whole sky in infrared light.
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The GLIMPSE data are also part of a citizen science project, where users can help catalog bubbles and other objects in our Milky Way galaxy. To participate, visit:
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Quelle: NASA

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Donnerstag, 20. März 2014 - 22:25 Uhr

Luftfahrt - Original-NASA T-38 Talon kommt in Aviation Heritage Park

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The T-38 Talon is being loaded in the desert this morning and  will be heading to Bowling Green.

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A NASA T-38 Talon airplane is on its way from Arizona to Bowling Green, where it is expected to arrive Saturday as the latest acquisition for the Aviation Heritage Park. 
“We are incredibly excited that we’re getting this aircraft,” said Bob Pitchford, vice president of the park.
NASA maintained a fleet of T-38s for astronauts to use for travel and as chase planes. This particular plane, with a tail number of 901, was used by all the astronauts who flew missions during the Mercury, Gemini and Apollo programs, including John Glenn, Alan Shepard and Neil Armstrong. 
The primary motivation for getting this plane is that astronaut and U.S. Marine Col. Terry Wilcutt, a Russellville native and Western Kentucky University graduate, also flew the plane, which will be the fifth aircraft at the Aviation Heritage Park. It will be used to tell Wilcutt’s story.
“We’ll be able to say, ‘Touch this plane ... and you have touched the manned spaceflight history of this country,’ ” said Ray Buckberry, a park board member.
The aircraft is set to arrive by flatbed trailer at the Bowling Green-Warren County Regional Airport on Saturday afternoon from
Davis-Monthan Air Force Base in Tucson, Ariz., where it has been since 2011 when NASA declared it surplus. Transporting the plane is costing around $40,000, and de-militarization costs about $17,000.
Dan Cherry, executive vice president of the park, was in Arizona earlier this week to ensure the plane was dismantled and loaded for transport. 
“We’re anxious to get it here. It has so much history,” he said.
Though some of the planes at the park have been severely damaged, the T-38 has no damage, Cherry said. Primarily, park volunteers will need to clean, sand and paint the plane to get it looking as good as new.  
“It’s going to require a good bit of work to get it the way we want it, but it will be a wonderful exhibit,” he said. 
Unlike the other planes at the park, which are on loan, the T-38 was given outright to Warren County. 
“We went through the same process as a Boy Scout would to get surplus cots,” Buckberry said.
Officials hope to have the exterior ready for the park’s annual Hanger Party in June, but it will be on display then regardless of its status.
“In whatever situation we’ll be in, we’ll display it,” Pitchford said.
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The latest plane for the Aviation Heritage Museum, a NASA T-38, is set to arrive at the airport on Saturday.
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Quelle: Bowling Green Daily News

2391 Views

Donnerstag, 20. März 2014 - 22:10 Uhr

Astronomie - Leos hellster Stern Regulus bedeckt, für den Nord-Osten der USA kurz verschwunden

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Look out for the best asteroid occultation ever from North America as the bright naked eye star Regulus winks out this week!

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The ground track of the shadow of the asteroid Erigone as it occults Regulus. AN graphic by Greg Smye-Rumsby.
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Hope for clear skies in north-eastern North America, including the New York metropolitan area, during the early morning of Thursday 20 March as the bright naked eye star Regulus, leader of the constellation of Leo the Lion, will disappear from sight for up to 14 seconds sometime around 2:06am to 2:08am EDT as it moves into the shadow of the 45-mile (73 kilometres) wide main belt asteroid (163) Erigone. The predicted track, as wide as the asteroid itself, sweeps across the ground at over 11,000 miles per hour south-east to north-west from New York, parts of Long Island, New Jersey, Connecticut, upstate New York and Ontario, Canada. This is a very rare event indeed; not many bright stars are occulted in this manner and it is even rarer for such an occultation to be potentially visible in such a populous area.So exciting is it that I would recommend all observers that have clear skies and are within striking distance of the shadow track to observe Regulus from 2am onwards and attempt to time the event.
Regulus is well-placed on the night of 19/20 March and by the time of the occultation it will be a favourable 33 degrees above the western horizon, about the same altitude as the waning gibbous Moon in the south. For once the strong moonlight or light pollution won't have a serous impact as Regulus is bright enough to easily shine through, even in heavily light-polluted area such as New York. The asteroid is very faint: at magnitude +12.4 it is over 25,000 times fainter and even large telescopes will fail to pick it out in Regulus' over-powering glare. Thankfully this is not a problem as the main goal is just to see Regulus wink-out. Astronomers are very confident of the timings of this event and the predicted path.
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Regulus is the brightest star in the constellation of Leo. AN graphic by Greg Smye-Rumsby.
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Of course you could just watch and enjoy this special event but accurately timing how long Regulus vanishes for can be very useful; if enough observers along the track time the disappearance and reappearance then the shape of Erigone can be determined by the duration of the wink-out at each location. If you have a radio-controlled clock you can use a stopwatch and verbally recording the observation is helpful. Many people will attempt to shoot a movie and this will be very worthwhile, especially with accurate timing to accompany it. Check out the International Occultation Timing Association (IOTA) website for more information if you wish to do some science during the occultation.
It is possible Erigone has a satellite asteroid in orbit around it. The only way to determine whether Erigone is in a double system is for observers away from the predicted track to watch Regulus closely to see if there is a secondary occultation and accurate timing of this would help tie down or constrain the companion's shape and size.
Even more science can be obtained by attempting to observe the suspected white dwarf companion of Regulus using high-speed photometric observations that measure the flux coming from Regulus and its companion. The American Association of Variable Star Observers (AAVSO) reports that such an observation may be possible if you are on the centre of the occultation track. The two stars are extremely close together, separated by 13 arcseconds at a position angle of either 168 or 348 degrees and the white dwarf would be occulted a mere 1.7 seconds after Regulus if you are on the centre line, meaning that it will reappear 1.7 seconds later too. Alternatively an observer just to one side of the track may see the flux of the white dwarf for the full duration of the Regulus occultation.
If skies are clear then this event, unlike many over-hyped observing opportunities, will truly live up to its 'once in a lifetime' billing. So set the alarm, dust off those binoculars, telescopes, cameras and stop-watches, rub the sleepiness from your eyes and enjoy the spectacle in whatever way you decide.
Quelle: AstronomyNow
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Update: 20.03.2014
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Rare Asteroid Eclipse of Bright Star Spoiled by Rain and Clouds

NEW YORK - A giant asteroid the size of Rhode Island eclipsed a bright star in the night sky in the wee hours of today (March 20), but the super-rare celestial event was spoiled by Mother Nature for many stargazers, experts say.
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Skywatchers stayed up late hoping to see the huge asteroid 163 Erigone eclipse the star Regulus — the 22nd brightest star in the night sky. The fast moving, distant space rock flew in front of the star in the constellation Leo, momentarily blotting out Regulus for as much as 14 seconds in along a small visibility track across northeast North America. Most observers, however, didn't get the rare celestial treat they were hoping for tonight. They got rain and clouds instead.
"It's miserable," astronomer Bob Berman said during the online Slooh Space Camera webcast of the Regulus event. "It's absolutely miserable. The weather is as bad as it possibly could be. It's really a double shame because it's been crystal clear for days. Isn't that the way it goes?" 
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The huge asteroid 163 Erigone passed in front of Regulus, blotting out the bright star for a few seconds for viewers in North America. Image uploaded March 20, 2014.
Credit: Slooh Space Camera



2683 Views

Donnerstag, 20. März 2014 - 21:34 Uhr

Raumfahrt - Pharmazeutische Unternehmen beteiligen sich an Hochwertigen Protein Kristallwachstum Experiment auf ISS-Kibo-Modul

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The Japan Aerospace Exploration Agency will begin the first experiment of the second series for the High-Quality Protein Crystal Growth Experiment (PCG)*1 using the environment on the Japanese Experiment Module "Kibo" of the International Space Station (ISS). Chugai Pharmaceutical Co., Ltd. and Interprotein Corporation will participate in the experiment.
Other than those companies, 18 academic organizations including universities will also join the experiment (as shown in List 1 below).
One of our objectives of the second series of the JAXA PCG is to contribute to enhancing Japan's industrial competitiveness by leveraging our world-class high quality PCG technology and knowhow in space that has been fostered. For fulfilling that objective, we established a new system*2 to facilitate application of our technology and knowhow by private companies such as an introduction of a trial-use system.
We are confident that JAXA PCG will contribute to the progress of research and development for medicine, industrial enzyme, and other areas by acquiring precise 3D protein structure data, which is the JAXA PCG target, and understanding the function of protein based on the precise structure data. We will conduct six experiments in space in total by regularly performing an experiment once every six months.
Quelle: JAXA
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Chugai to Participate in
High-Quality Protein Crystal Growth Experiment
in the International Space Station, “Kibo,” as Private Company
March 20, 2014 (Tokyo) - Chugai Pharmaceutical Co., Ltd. [Head Office: Chuo-ku, Tokyo;  Chairman & CEO: Osamu Nagayama) (hereafter, Chugai)] announced today that it will participate in the high-quality protein crystal growth experiment under microgravity environment in “Kibo,” the Japanese Experiment Module on the International Space Station conducted by Japan Aerospace Exploration Agency (hereafter, JAXA PCG).
 
JAXA PCG is the protein crystal growth experiment conducted at “Kibo” based on JAXA’s accumulated high-quality protein crystal growth technology. In the first experiment of the second series, proteins to be crystallized will be filled up into JAXA’s crystallization instrument (named as JCB-SGT) and launched by the Soyuz Spacecraft on March 26, 2014. Koichi Wakata, the Japanese astronaut who now resides at the international space station for an extended period, will support the first experiment.
 
Chugai applied for the Industrial R&D course of JAXA PCG for target drug discovery and its protein was selected as one of the targeted proteins for the first experiment of the second series by the “High-Quality Protein Crystal Growth Experiment Working Group” consisting of external members which evaluates candidates for targeted proteins in the view of its safety and feasibility etc. With this experiment, Chugai is aiming at revealing a precise 3D structure of the protein by the high-quality crystals grown under the space microgravity environment to help understand the functions of drug candidate protein and create revolutionary new drugs.
 
【Outline of the First Experiment of the Second Series on JAXA PCG】
Launch date:March 26, 2014
Launch site:Baikonur Cosmodrome, Kazakhstan
Scheduled return date:May 14, 2014
Landing location:Kazakhstan
Return flight:By Soyuz Spacecraft
Quelle: CHUGAI Pharmaceutical Co.Ltd
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Quelle: Interprotein

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Donnerstag, 20. März 2014 - 13:43 Uhr

UFO-Forschung - IFO- Universität: Sterne und Planeten

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In Allan Hendry’s UFO handbook, he lists the most common night time objects reported as UFOs are stars and planets.
A great number of people during his evaluation of UFOs at CUFOS seemed to be completely ignorant of the night sky. This is nothing new. The USAF knew that people often would state that stars and planets were UFOs. They were often ridiculed for suggesting these as an explanation
for a UFO report. This was especially true in high publicity cases. However, the truth of the matter is that planets and stars are big UFO pretenders. One has to just look at the MUFON/NUFORC databases to see it.
Is it astronomical?
There are four items that stand out that will quickly identify most astronomical (stars/planets) objects.
Does it return every night in the
1. same general location?
Does it slowly descend in the west or
2. does it slowly ascend in the east?
Is it visible for long periods of time?
3.Does it appear as the sky gets dark or
4. disappear as the sky gets light?
All of these will identify most astronomical
UFO reports. However, one has to consider that witnesses can make mistakes that make it difficult to identify them as astronomical objects.
Scintillation effects Bright stars often twinkle violently when close to the horizon. This twinkling can produce changes in color and apparent motion changes. The astronomical
term for this is called scintillation and is most common with bright stars close to horizon. However, I have seen the star Sirius do this at very high angles of elevation. The brighter the star, the more likely the effects of scintillation will distort its appearance. Planets No other celestial object is responsible for UFO reports than the planet Venus.
However, the planets Jupiter and Mars (every two years near opposition) can produce them as well. Planets are usually referred to as star-like by many witnesses but they often can be described as having significant angular size, emitting spikes, and casting shadows. There are many cases of “trained observers”
being fooled by the planets Venus and Jupiter.
Probably the best documented sighting that demonstrates this is case number 37 in the Condon study. All sorts of things were done involving the planet Venus. A police officer pursued it and others thought it followed them. A plane was sent to pursue it based on direction by the officers and a radar operator, who claimed to have a radar contact. Dr. J. Allen Hynek would describe the case as “... a fantastic example of how persuasive the planet Venus can be as a nonscreened UFO. Police officers in 11 counties were “taken in” by this planet. It is a case of particular value to psychologists and, one is tempted to say, to those responsible for hiring policemen.”1 
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Dr. Roy Craig would describe some of the effects observed by the “trained observers”, who felt they were pursuing or being followed by the planet Venus:
The apparent pursuit of moving vehicles, or flight from them, is characteristic of any distant object which is imagined to be close to the observer. Because of the object’s great distance, it remains essentially the same direction from the observer as the observer moves. Because of the object’s great distance, it remains essentially the same direction from the observer as the observer moves. Compared with trees or terrain nearby which change in direction as the observer moves past them, the object, retaining a constant direction, does seem to be moving the same speed and direction as any observer who thinks it no more distant than the reference terrain...
It is a characteristic of this “pursuit” that the object stops when the observer stops, resumes its motion as the observer resumes motion, goes the opposite direction when the observer reverses direction, and travels at whatever speed the observer happens to travel.2
The lesson learned here is not to sell the planet Venus short and dismiss it simply because an observer indicates motion.
Daylight Planets
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Venus and, sometimes, Jupiter can be seen in the daytime with the naked eye if one knows where to look. A person who catches these objects in the sky, will often stare at them long enough to convince themselves they are seeing something strange. Using binoculars can make matters worse as one might be able to see a “half-moon” shape for Venus when it is near 50% sunlit. This can make people think they are seeing some sort of dome shaped object.
Dr. Roy Craig describes an incident early in the Condon study where a UFO was seen in broad daylight by team members.
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The Administrative Assistant, Mary Lou Armstrong, was upset with the local AF base UFO officer who suggested it might be Venus. She felt no scientist could be fooled by Venus. Imagine her surprise when the scientists examined their data and determined they were seeing Venus in the daytime!
Belief over reason I do not like to use Venus as an explanation for a UFO sighting unless there is good reason to consider it. One has to be pretty sure that the direction, time and description can be matched with a misperception of the planet. Venus has a UFOlogical stigma associated with it, where UFO proponents tend to dismiss it as a valid explanation even when it fits (see Jimmy Carter UFO).
It isn’t only UFOlogists who are hard to convince. Try convincing somebody whose sighting is extraordinary to them is only the planet Venus. An example of this can be found in a recent MUFON UFO report:
First spotted and photographed in November 2008 above my house in Reading, PA. Spotted sporadically throughout 2009. Since March 2010 it appears every
night around 8:20pm and is usually gone in an hour. Don’t even TRY telling me this is VENUS as you did with so many others.
Apparently, the MUFON investigators keep telling him it is Venus but he remains unconvinced. All of these descriptions match Venus evening apparitions. The photographs submitted with this report look a lot like a star-like object imaged with a high zoom and at a low angle of elevation. There is nothing to dismiss the idea that this is Venus. The power to believe one is viewing a “true” UFO can often override any logic that can be applied.
Notes and references
1. Hynek, J. Allen. The UFO Experience A Scientific Inquiry. New York: Marlowe & Company 1972. p. 205
2. Craig, Roy. UFOs: An Insider’s View of the Official Quest for Evidence. Denton: University of North Texas Press, 1995. p. 47
3. MUFON case management system. Started sporadically in November 2008. In 2010 we see it nightly for about 45 minutes. Submitted May 4, 2010.
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Quelle: SUNlite 4/2010

Tags: UFO-Forschung 

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Donnerstag, 20. März 2014 - 12:45 Uhr

Astronomie - NASA veröffentlicht Interaktive Mosaik von Mond Nordpol

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19.03.2014

A new interactive mosaic from NASA's Lunar Reconnaissance Orbiter covers the north pole of the moon from 60 to 90 degrees north latitude at a resolution of 6-1/2 feet (2 meters) per pixel. Close-ups of Thales crater (right side) zoom in to reveal increasing levels of detail.
Image Credit: NASA/GSFC/Arizona State University
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Scientists, using cameras aboard NASA's Lunar Reconnaissance Orbiter (LRO), have created the largest high resolution mosaic of our moon’s north polar region. The six-and-a-half feet (two-meters)-per-pixel images cover an area equal to more than one-quarter of the United States.
Web viewers can zoom in and out, and pan around an area. Constructed from 10,581 pictures, the mosaic provides enough detail to see textures and subtle shading of the lunar terrain. Consistent lighting throughout the images makes it easy to compare different regions.
"This unique image is a tremendous resource for scientists and the public alike," said John Keller, LRO project scientist at NASA's Goddard Space Flight Center, Greenbelt, Md. "It's the latest example of the exciting insights and data products LRO has been providing for nearly five years."
The images making up the mosaic were taken by the two LRO Narrow Angle Cameras, which are part of the instrument suite known as the Lunar Reconnaissance Orbiter Camera (LROC). The cameras can record a tremendous dynamic range of lit and shadowed areas.
"Creation of this giant mosaic took four years and a huge team effort across the LRO project," said Mark Robinson, principal investigator for the LROC at Arizona State University in Tempe. "We now have a nearly uniform map to unravel key science questions and find the best landing spots for future exploration."
The entire image measures 931,070 pixels square – nearly 867 billion pixels total. A complete printout at 300 dots per inch – considered crisp resolution for printed publications – would require a square sheet of paper wider than a professional U.S. football field and almost as long. If the complete mosaic were processed as a single file, it would require approximately 3.3 terabytes of storage space. Instead, the processed mosaic was divided into millions of small, compressed files, making it manageable for users to view and navigate around the image using a web browser.
LRO entered lunar orbit in June 2009 equipped with seven instrument suites to map the surface, probe the radiation environment, investigate water and key mineral resources, and gather geological clues about the moon's evolution.
Researchers used additional information about the moon's topography from LRO's Lunar Orbiter Laser Altimeter, as well as gravity information from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission, to assemble the mosaic. Launched in September 2011, the GRAIL mission, employing twin spacecraft named Ebb and Flow, generated a gravity field map of the moon -- the highest resolution gravity field map of any celestial body.
LRO is managed by Goddard for the Science Mission Directorate (SMD) at NASA Headquarters in Washington. LROC was designed and built by Malin Space Science Systems and is operated by the University of Arizona. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed the GRAIL mission for SMD.
Quelle: NASA
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Update: 20.03.2014
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ASU camera creates stunning mosaic of moon's polar region

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Printed at 300 dpi (a high-quality printing resolution that requires you to peer very closely to distinguish pixels), the LROC northern polar mosaic would be larger than a football field.
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Today, the Lunar Reconnaissance Orbiter Camera (LROC), run by the Arizona State University-based team under professor Mark Robinson, released what very well may be the largest image mosaic available on the web. This map offers a complete picture of the moon’s northern polar region in stunning detail.
On December 11, 2011, after two and a half years in a near-circular polar orbit, NASA’s Lunar Reconnaissance Orbiter (LRO) entered an elliptical polar orbit, with the periapsis (point where the LRO is closest to the surface) near the south pole, and the apoapsis (point where LRO is furthest from the surface) near the north pole of the moon. The increased altitude over the northern hemisphere enables the two narrow angle cameras and the wide angle camera to capture more terrain in each image acquired in the northern hemisphere.
The resulting LROC northern polar mosaic is comprised of 10,581 narrow angle camera images, collected over four years, and covers the latitude range of zero to 60 degrees north.
In the fall of 2010, the LROC team produced its first mosaic of the moon’s northern polar region, but it doesn’t even compare to this new mosaic, with its 50-times-higher resolution, and over 680 gigapixels of valid image data covering a region of the moon slightly larger than the combined area of Alaska and Texas – at a resolution of 2 meters per pixel.
To create the mosaic, each LROC narrow angle camera image was map projected on a 30-meters-per-pixel lunar orbiter laser altimeter-derived digital terrain model using a software package (written by the United States' Geological Survey) called Integrated Software for Imagers and Spectrometers.
The northern polar mosaic was assembled from individual “collar” mosaics. Each collar mosaic was acquired by imaging the same latitude once every two-hour orbit for a month, during which time the rotation of the moon steadily brought every longitude into view. Each collar mosaic has very similar lighting from start to end, and covers 1 to 3 degrees of latitude.
The mosaic was originally assembled as 841 large tiles, due to the sheer volume of data. If the mosaic was processed as a single file, it would have been approximately 3.3 terabytes in size. Part of the large size is due to the incredible dynamic range of the narrow angle cameras. The raw images are recorded as 12-bit data (4,096 gray levels), then processed to normalized reflectance (a quantitative measure of the percentage of light reflected from each spot on the ground).
To preserve the subtle shading gradations of the raw images during processing, the narrow angle camera images are stored as 32-bit, floating-point values (millions of gray levels). The 32-bit values are four times the disk size of the finalized 8-bit (255 gray levels) representation most computers use to display grayscale images. The conversion process from 32-bit to 8-bit pixels results in saturation (a group of pixels all with the maximum value of 255) in the brightest areas.
Even with the conversion, the compressed JPEG images that make up the final product take up almost a terabyte of disk space.
In total, the massive mosaic required 17,641,035 small tiles to produce the final product.
“The (northern polar mosaic) is another example of LRO observations paving the way for science discoveries and future missions of exploration. Creation of this giant mosaic took four years and a huge team effort across the LRO project. We now have a nearly uniform map to unravel key science questions and find the best landing spots for future exploration,” says Robinson, a professor in the School of Earth and Space Exploration in ASU’s College of Liberal Arts and Sciences.
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Quelle:Arizona State University


2972 Views

Donnerstag, 20. März 2014 - 09:28 Uhr

Raumfahrt - All-Tag auf der ISS

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Commander Koichi Wakata replaces a manifold bottle in the Combustion Integrated Rack aboard the International Space Station.
Image Credit: NASA TV
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Station Astronauts Work With Spacesuit; New Crew Set for Monday Launch
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The International Space Station’s Expedition 39 crew performed microgravity research and spacesuit maintenance Wednesday while awaiting next week’s arrival of a Soyuz spacecraft that will double the station’s population.
Commander Koichi Wakata began the day with a quick test of the station’s drinking water using the Total Organic Carbon Analyzer, making sure that the recycled water remains free of contaminants.
Afterward the Japan Aerospace Exploration Agency astronaut replaced a manifold bottle in the Combustion Integrated Rack. This facility, which includes an optics bench, combustion chamber, fuel and oxidizer control and five different cameras, allows a variety of combustion experiments to be performed safely aboard the station. Fire quite behaves differently in the absence of gravity, and the experiments performed in this facility could lead to improvements in spacecraft materials selection and strategies for putting out accidental fires aboard spacecraft. The research also provides scientists with improved computational models that will aid in the design of fire detection and suppression systems here on Earth.
Wakata also replaced some burned-out light bulbs in two of the eight EXPRESS racks aboard the complex. Short for EXpedite the PRocessing of Experiments for Space Station, EXPRESS racks support a variety science experiments in any discipline by providing structural interfaces, power, data, cooling, water and other items. Each EXPRESS rack can accommodate up to ten small payloads.
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Flight Engineer Rick Mastracchio works with spacewalk gear in the Quest airlock of the International Space Station.
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Flight Engineer Rick Mastracchio of NASA meanwhile deployed a new control unit for the Space Acceleration Measurement System, or SAMS, and transferred its related software to a new laptop computer. SAMS is an ongoing study of the vibrations and accelerations on the station resulting from the operation of hardware, crew exercise, dockings and activities such as the debris avoidance maneuver Sunday night to steer the station clear of a piece of satellite debris.
After a break from lunch, Mastracchio and Wakata teamed up in the Quest airlock for some spacesuit maintenance to make sure that the equipment remains ready to support a spacewalk. With guidance from NASA astronaut Doug Wheelock serving as Capcom at Houston’s Mission Control Center, Mastracchio and Wakata replaced a Condensate Water Relief Valve Filter inside of one the four U.S. spacesuits aboard the station. New parts and a new spacesuit will be coming up to the station aboard the SpaceX Dragon cargo craft, and a spacesuit with a defective sublimator will return to Earth aboard Dragon at the end of its mission. The departing spacesuit is not the one worn by European Space Agency astronaut Luca Parmitano during a July spacewalk that was terminated early when the helmet began to fill with water. That spacesuit was repaired on orbit by the station crew and returned to service. The SpaceX-3 commercial resupply services flight is targeted for launch no earlier than March 30.
Quelle: NASA

Tags: ISS-Commander Koichi Wakata Rick Mastracchio ISS 

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Donnerstag, 20. März 2014 - 08:47 Uhr

Astronomie - Strahlungsgürtel der Erde bekommt seine 'Streifen' durch die Rotation

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The Earth's radiation belts, shown in this illustration, can change shape and intensity. The Earth's rotation and its interaction with surrounding electric and magnetic fields may shape the stripes that appear in the innermost belt, scientists suggest.

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Earth’s spin may be giving the planet’s inner radiation belt zebralike stripes.
Scientists thought interactions between particles from the sun and the belt would cause these types of patterns. But new observations show that the inner belt has organized layers of electrons even when the sun spews relatively few particles in the planet’s direction. Simulations also show that Earth’s rotation can influence the magnetic and electric fields that interact with the electrons in the belt and cause the stripes, scientists report March 19 in Nature.
The result may provide clues about what is happening in the radiation belts of Jupiter, Neptune and Uranus.
Quelle: ScienceNews
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NASA's Van Allen Probes Reveal Zebra Stripes in Space
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Scientists have discovered a new, persistent structure in one of two radiation belts surrounding Earth. NASA's twin Van Allen Probes spacecraft have shown that high-energy electrons in the inner radiation belt display a persistent pattern that resembles slanted zebra stripes. Surprisingly, this structure is produced by the slow rotation of Earth, previously considered incapable of affecting the motion of radiation belt particles, which have velocities approaching the speed of light.
Scientists had previously believed that increased solar wind activity was the primary force behind any structures in our planet's radiation belts. However, these zebra stripes were shown to be visible even during low solar wind activity, which prompted a new search for how they were generated. That quest led to the unexpected discovery that the stripes are caused by the rotation of Earth. The findings are reported in the March 20, 2014, issue of Nature.
"It is because of the unprecedented resolution of our energetic particle experiment, RBSPICE, that we now understand that the inner belt electrons are, in fact, always organized in zebra patterns," said Aleksandr Ukhorskiy, lead author of the paper at The Johns Hopkins Applied Physics Laboratory, or APL, in Laurel, Md. "Furthermore, our modeling clearly identifies Earth's rotation as the mechanism creating these patterns. It is truly humbling, as a theoretician, to see how quickly new data can change our understanding of physical properties."
Because of the tilt in Earth's magnetic field axis, the planet's rotation generates an oscillating, weak electric field that permeates through the entire inner radiation belt. To understand how that field affects the electrons, Ukhorskiy suggested imagining that the electrons are like a viscous fluid. The global oscillations slowly stretch and fold the fluid, much like taffy is stretched and folded in a candy store machine. The stretching and folding process results in the striped pattern observed across the entire inner belt, extending from above Earth's atmosphere, about 500 miles above the planet's surface up to roughly 8,000 miles.
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Two giant belts of radiation surround Earth. The inner belt is dominated by electrons and the outer one by protons.
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The radiation belts are dynamic doughnut-shaped regions around our planet, extending high above the atmosphere, made up of high-energy particles, both electrons and charged particles called ions, which are trapped by Earth's magnetic field. Radiation levels across the belts are affected by solar activity that causes energy and particles to flow into near-Earth space. During active times, radiation levels can dramatically increase, which can create hazardous space weather conditions that harm orbiting spacecraft and endanger humans in space. It is the goal of the Van Allen Probes mission to understand how and why radiation levels in the belts change with time.
"The RBSPICE instrument has remarkably fine resolution and so it was able to bring into focus a phenomena that we previously didn't even know existed," said David Sibeck, the mission scientist for the Van Allen Probes at NASA's Goddard Space Flight Center in Greenbelt, Md. "Better yet, we have a great team of scientists to take advantage of these unprecedented observations: We couldn't have interpreted this data without analysis from strong theoreticians."
NASA launched the Van Allen Probes in the summer of 2012. APL built and operates the probes for NASA's Science Mission Directorate. This is the second mission in NASA's Living With a Star program, which Goddard manages. The program explores aspects of the connected sun-Earth system that directly affect life and society.
Quelle: NASA
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NASA Spacecraft Reveal New “Zebra Stripes” Structure in Earth’s Inner Radiation Belt

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Scientists have discovered a new, persistent structure in Earth’s inner radiation belt using data from the twin NASA Van Allen Probes spacecraft. Most surprisingly, this structure is produced by the slow rotation of Earth, previously considered incapable of affecting the motion of radiation belt particles, which have velocities approaching the speed of light.
Data from the Van Allen Probes Ion Composition Experiment (RBSPICE) on board each of the twin spacecraft orbiting Earth revealed that the highly energized population of electrons of the inner radiation belt is organized into very structured patterns that resemble slanted zebra stripes. Scientists had previously believed that increased solar wind activity was the primary force behind any structures in our planet’s radiation belts. These zebra stripes were shown to be visible even during low solar wind activity, which prompted a search for a new physical mechanism of their generation. That quest led to the surprising discovery that the stripes are caused by rotation of Earth. The findings are reported in the Mar. 20 issue of the journal Nature.
“It is because of the unprecedented high energy and temporal resolution of our energetic particle experiment, RBSPICE, that we now understand that the inner belt electrons are, in fact, always organized in zebra patterns,” said Aleksandr Ukhorskiy of the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Md., co-investigator on RBSPICE and lead author of the paper. “Furthermore, our modeling clearly identifies Earth’s rotation as the mechanism creating these patterns. It is truly humbling, as a theoretician, to see how quickly new data can change our understanding of physical properties.” 
Because of the tilt in Earth’s magnetic field axis, the planet’s rotation generates an oscillating, weak electric field that permeates through the entire inner radiation belt. To understand how that field affects the electrons, Ukhorskiy suggested an analogy: “If the inner belt electron populations are viewed as a viscous fluid, these global oscillations slowly stretch and fold that fluid, much like taffy is stretched and folded in a candy store machine,” he said. This stretching and folding process results in the striped pattern observed across the entire inner electron belt, extending from above Earth’s atmosphere (about 500 miles, or 800 kilometers, above the planet’s surface) up to roughly 8,000 miles (13,000 kilometers). 
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The Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE) is a time-of-flight versus energy spectrometer, the most prominent feature of which is the sensor known as the “puck” (because of its resemblance to a hockey puck). RBSPICE measures medium energy protons, electrons, and ions (H+, He+, and O+) as functions of energy and angle, and is capable of measuring the full range of expected ring current energies, intensities, and ion compositions from quiet conditions to extreme events, with a factor of ten margin against intensity saturation.
Credit: NASA/JHUAPL
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The radiation belts are dynamic doughnut-shaped regions around our planet, extending high above the atmosphere, made up of high-energy particles (electrons and ions) that are trapped by Earth’s magnetic field. Radiation levels across the belts are affected by solar activity (such as solar storms) and can ebb and flow. During active conditions, radiation levels can dramatically increase, which can create hazardous space weather conditions that harm orbiting spacecraft and endanger humans in space. It is the goal of the Van Allen Probes mission to understand how and why radiation levels in the belts change with time.
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"Zebra stripes" in the inner radiation belt: An example of energetic electron spectra, measured on June 18, 2013 by NASA's twin Van Allen Probes in the inner radiation belt during quiet time during low solar activity. The striped, banded pattern is caused by the rotation of the Earth, previously thought to have no effect on the highly energetic particles of the radiation belt. 
Credit: A. Ukhorskiy/JHUAPL
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“This is another fundamental understanding made possible thanks to the highly detailed data being returned from these remarkable spacecraft,” said Louis Lanzerotti, distinguished research professor of physics at the Center for Solar-Terrestrial Research at the New Jersey Institute of Technology, principal investigator for RBSPICE, and a co-author on the paper. “It is amazing how Earth’s space environment, including the radiation belts, continue to surprise us even after we have studied them for over 50 years. Our understanding of the complex structures of the belts, and the processes behind the belts’ behaviors, continues to grow, all of which contribute to the eventual goal of providing accurate space weather modeling.”
“This finding tells us something new and important about how the universe operates,” said Barry Mauk of APL, Van Allen Probes project scientist and an author of the paper. “The new results reveal a new large-scale physical mechanism that can be important for planetary radiation belts throughout the solar system. An instrument similar to RBSPICE is now on its way to Jupiter on NASA’s Juno mission, and we will be looking for the existence of zebra stripe-like patterns in Jupiter’s radiation belts.” 
NASA launched the twin Van Allen probes in the summer of 2012. APL built and operates the probes for NASA’s Science Mission Directorate. The Van Allen Probes are the second mission in NASA’s Living With a Star program, managed by NASA’s Goddard Space Flight Center in Greenbelt, MD. The program explores aspects of the connected sun-Earth system that directly affect life and society.
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Quelle: NASA 

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