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Pėrdorimi i ēėshtjes
I vjetėr 8.9.2010, 23:31   1
Anėtarėsuar: 6.2001

Astronomi: Trupat qiellorė bashkėveprojnė me rryma elektromagnetike

Teza kryesore ėshtė se "kanalet, vijat, gropat" etj. nė pjesėn dėrrmuese tė tyre nė trupat qiellore shkaktohen nga rryma elektromagentike. Burimi i interpretimeve ėshtė nga projekti i modelit elektromagnetik tė gjithėsisė qė po zhvillohet nga ndėrrimi i mijėvjeēarit, po videot janė tė mira si hyrje pėr dikė qė nuk ėshtė nė dijeni tė tezės.

Po njėsoj shpjegohen dhe veēoritė e sjellja e kometave:

  Pėrgjigju duke cituar
I vjetėr 5.12.2010, 10:46   2
Anėtarėsuar: 6.2001
Ka pas njė artikull interesant para ca ditėsh pėr "zbulimin" e fushave magnetike nė yjet e reja. Shpjegimi pėr kėto gulfat (jets) yjore duket njėsoj me shpjegimin pėr gulfat dhe natyrėn E/M tė dukurive qė vėrehen mbi kometat, qė pėrmenden nė videot sipėr:

First Evidence for Magnetic Field in Protostar Jet: Magnetism Common to All Cosmic Jets?

ScienceDaily (Nov. 26, 2010) — Astronomers have found the first evidence of a magnetic field in a jet of material ejected from a young star, a discovery that points toward future breakthroughs in understanding the nature of all types of cosmic jets and of the role of magnetic fields in star formation.

Throughout the Universe, jets of subatomic particles are ejected by three phenomena: the supermassive black holes at the cores of galaxies, smaller black holes or neutron stars consuming material from companion stars, and young stars still in the process of gathering mass from their surroundings. Previously, magnetic fields were detected in the jets of the first two, but until now, magnetic fields had not been confirmed in the jets from young stars.

"Our discovery gives a strong hint that all three types of jets originate through a common process," said Carlos Carrasco-Gonzalez, of the Astrophysical Institute of Andalucia Spanish National Research Council (IAA-CSIC) and the National Autonomous University of Mexico (UNAM).

The astronomers used the National Science Foundation's Very Large Array (VLA) radio telescope to study a young star some 5,500 light-years from Earth, called IRAS 18162-2048. This star, possibly as massive as 10 Suns, is ejecting a jet 17 light-years long.

Observing this object for 12 hours with the VLA, the scientists found that radio waves from the jet have a characteristic indicating they arose when fast-moving electrons interacted with magnetic fields. This characteristic, called polarization, gives a preferential alignment to the electric and magnetic fields of the radio waves.

"We see for the first time that a jet from a young star shares this common characteristic with the other types of cosmic jets," said Luis Rodriguez, of UNAM.

The discovery, the astronomers say, may allow them to gain an improved understanding of the physics of the jets as well as of the role magnetic fields play in forming new stars. The jets from young stars, unlike the other types, emit radiation that provides information on the temperatures, speeds, and densities within the jets. This information, combined with the data on magnetic fields, can improve scientists' understanding of how such jets work.

"In the future, combining several types of observations could give us an overall picture of how magnetic fields affect the young star and all its surroundings. This would be a big advance in understanding the process of star formation," Rodriguez said.

Carrasco-Gonzalez and Rodriguez worked with Guillem Anglada and Mayra Osorio of the Astrophysical Institute of Andalucia, Josep Marti of the University of Jaen in Spain, and Jose Torrelles of the University of Barcelona. The scientists reported their findings in the November 26 edition of Science.

The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

  Pėrgjigju duke cituar
I vjetėr 16.1.2016, 18:52   3
Anėtarėsuar: 6.2001
Sonda SDO regjistron harqet magnetike tė Diellit:

NASA’s SDO Captures Cascading Magnetic Arches

A dark solar filament above the sun's surface became unstable and erupted on Dec. 16-17, 2015, generating a cascade of magnetic arches. A small eruption to the upper right of the filament was likely related to its collapse. The arches of solar material appear to glow as they emit light in extreme ultraviolet wavelengths, highlighting the charged particles spinning along the sun's magnetic field lines. This video was taken in extreme ultraviolet wavelengths of 193 angstroms, a type of light that is typically invisible to our eyes, but is colorized here in bronze.

  Pėrgjigju duke cituar
I vjetėr 30.1.2016, 11:01   4
Anėtarėsuar: 6.2001
Dielli si trup i mirėfilltė magnetik - fillon leximi praktik pėr publikun nga tė dhėnat e para 5 viteve:

NASA: Understanding the Magnetic Sun

The surface of the sun writhes and dances. Far from the still, whitish-yellow disk it appears to be from the ground, the sun sports twisting, towering loops and swirling cyclones that reach into the solar upper atmosphere, the million-degree corona – but these cannot be seen in visible light. Then, in the 1950s, we got our first glimpse of this balletic solar material, which emits light only in wavelengths invisible to our eyes.

Once this dynamic system was spotted, the next step was to understand what caused it. For this, scientists have turned to a combination of real time observations and computer simulations to best analyze how material courses through the corona. We know that the answers lie in the fact that the sun is a giant magnetic star, made of material that moves in concert with the laws of electromagnetism.

“We’re not sure exactly where in the sun the magnetic field is created,” said Dean Pesnell, a space scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “It could be close to the solar surface or deep inside the sun – or over a wide range of depths.”

Getting a handle on what drives that magnetic system is crucial for understanding the nature of space throughout the solar system: The sun's magnetic field is responsible for everything from the solar explosions that cause space weather on Earth – such as auroras – to the interplanetary magnetic field and radiation through which our spacecraft journeying around the solar system must travel.

So how do we even see these invisible fields? First, we observe the material on the sun. The sun is made of plasma, a gas-like state of matter in which electrons and ions have separated, creating a super-hot mix of charged particles. When charged particles move, they naturally create magnetic fields, which in turn have an additional effect on how the particles move. The plasma in the sun, therefore, sets up a complicated system of cause and effect in which plasma flows inside the sun – churned up by the enormous heat produced by nuclear fusion at the center of the sun – create the sun's magnetic fields. This system is known as the solar dynamo.

We can observe the shape of the magnetic fields above the sun's surface because they guide the motion of that plasma – the loops and towers of material in the corona glow brightly in EUV images. Additionally, the footpoints on the sun’s surface, or photosphere, of these magnetic loops can be more precisely measured using an instrument called a magnetograph, which measures the strength and direction of magnetic fields.

Next, scientists turn to models. They combine their observations – measurements of the magnetic field strength and direction on the solar surface – with an understanding of how solar material moves and magnetism to fill in the gaps. Simulations such as the Potential Field Source Surface, or PFSS, model – shown in the accompanying video – can help illustrate exactly how magnetic fields undulate around the sun. Models like PFSS can give us a good idea of what the solar magnetic field looks like in the sun’s corona and even on the sun’s far side.

A complete understanding of the sun’s magnetic field – including knowing exactly how it’s generated and its structure deep inside the sun – is not yet mapped out, but scientists do know quite a bit. For one thing, the solar magnetic system is known to drive the approximately-11-year activity cycle on the sun. With every eruption, the sun’s magnetic field smooths out slightly until it reaches its simplest state. At that point the sun experiences what's known as solar minimum, when solar explosions are least frequent. From that point, the sun’s magnetic field grows more complicated over time until it peaks at solar maximum, some 11 years after the previous solar maximum.

“At solar maximum, the magnetic field has a very complicated shape with lots of small structures throughout – these are the active regions we see,” said Pesnell. “At solar minimum, the field is weaker and concentrated at the poles. It’s a very smooth structure that doesn’t form sunspots.”

Take a look at the side-by-side comparison to see how the magnetic fields change, grew and subsided from January 2011 to July 2014. You can see that the magnetic field is much more concentrated near the poles in 2011, three years after solar minimum. By 2014, the magnetic field has become more tangled and disorderly, making conditions ripe for solar events like flares and coronal mass ejections.

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  Pėrgjigju duke cituar
I vjetėr 14.2.2016, 00:09   5
Anėtarėsuar: 6.2001
Nga sonda SDO:

Satellite time-lapse video shows an entire year of the Sun in stunning ultra high definition

Since NASA’s Solar Dynamics Observatory spacecraft became operational in late April of 2010, it has provided a trove of valuable data — and mind-boggling views of the Sun.

This past year was no exception, as the video above shows. It consists of imagery acquired by SDO from Jan. 1, 2015, to Jan. 28, 2016, in one stunning time-lapse sequence.

Click to play it on YouTube. And if your internet speed is high enough, watch it in ultra-high definition: 3840 x 2160 (in other words, 4K) and 29.97 frames per second. At this level, the video consists of one SDO image taken every two hours for almost a year.

SDO’s Atmospheric Imaging Assembly (AIA) instrument actually captures a shot of the Sun even more frequently than that: once every 12 seconds — and in 10 different wavelengths. The images that went into this time-lapse video were acquired at a wavelength of 171 angstroms, which is in the extreme ultraviolet (and invisible to our eyes).

Viewing the Sun at this wavelength allows us to see the ebb and flow of million-degree-Fahrenheit material in the Sun’s atmosphere, called the corona. Among other things, we can see material aligning in complex ways along the lines of magnetic force that weave through the corona. Hot, active regions glow with particular intensity. Explosive eruptions of radiation caused by the sudden release of built up magnetic energy can be seen too.

So can cooler, gargantuan loops and filaments of material, called prominences, consisting of plasma flowing along twisted magnetic field lines. At about three minutes into the video, you can see a line of these prominences seeming to hover within the corona.

When the twisted magnetic structures suspending a prominence within the corona become unstable, they can explode, propelling plasma outward into space in what’s known as a coronal mass ejection, or CME.

The closeup above is one of the more dramatic examples of a solar eruption captured by SDO. The resulting CME struck a glancing blow to Earth’s bubble of magnetic energy, the magnetosphere.

Here’s a video of the same eruption, showing the event from different perspectives and in varying wavelengths.

Those green tones match beautifully the aurora that ignited over the skies of Whitehorse in Canada’s Yukon Territory on Sept. 3, 2012, when the CME jostled Earth’s magnetosphere. Click on the thumbnail at right to see a beautiful photo of the display shot by David Cartier, Sr. (It will open on NASA’s website.)

Lastly, I’ll leave you with one of SDO’s most recent images of a solar prominence. It was acquired on Feb. 3, 2016. NASA calls it an “unraveling prominence,” for reasons that I think will be clear when you click on the image and then watch a time-lapse video of the event:


Launched on Feb. 11, 2010, SDO recently observed its 6th anniversary in space. It’s primary science mission was supposed to last a little over five years. We’re past that now, and the spacecraft seems to be going strong. When launched it had enough fuel to do maneuvering for 10 years. So if all goes well, we’ll continue to enjoy spectacular imagery, and science, from SDO for some years to come.

  Pėrgjigju duke cituar
I vjetėr 11.3.2016, 13:16   6
Anėtarėsuar: 6.2001
Kometa C/2013 A1 destabilizon magnetosferėn e Marsit, matjet nga qendra Goddard, sonda hapėsinore MAVEN:

Close comet flyby threw Mars' magnetic field into chaos

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Just weeks before the historic encounter of comet C/2013 A1 (Siding Spring) with Mars in October 2014, NASA's Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft entered orbit around the Red Planet. To protect sensitive equipment aboard MAVEN from possible harm, some instruments were turned off during the flyby; the same was done for other Mars orbiters. But a few instruments, including MAVEN's magnetometer, remained on, conducting observations from a front-row seat during the comet's remarkably close flyby.

The one-of-a-kind opportunity gave scientists an intimate view of the havoc that the comet's passing wreaked on the magnetic environment, or magnetosphere, around Mars. The effect was temporary but profound.

"Comet Siding Spring plunged the magnetic field around Mars into chaos," said Jared Espley, a MAVEN science team member at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "We think the encounter blew away part of Mars' upper atmosphere, much like a strong solar storm would."

Unlike Earth, Mars isn't shielded by a strong magnetosphere generated within the planet. The atmosphere of Mars offers some protection, however, by redirecting the solar wind around the planet, like a rock diverting the flow of water in a creek. This happens because at very high altitudes Mars' atmosphere is made up of plasma – a layer of electrically charged particles and gas molecules. Charged particles in the solar wind interact with this plasma, and the mingling and moving around of all these charges produces currents. Just like currents in simple electrical circuits, these moving charges induce a magnetic field, which, in Mars' case, is quite weak.

Comet Siding Spring is also surrounded by a magnetic field. This results from the solar wind interacting with the plasma generated in the coma – the envelope of gas flowing from a comet's nucleus as it is heated by the sun. Comet Siding Spring's nucleus – a nugget of ice and rock measuring no more than half a kilometer (about 1/3 mile) – is small, but the coma is expansive, stretching out a million kilometers (more than 600,000 miles) in every direction. The densest part of the coma – the inner region near the nucleus – is the part of a comet that's visible to telescopes and cameras as a big fuzzy ball.

When comet Siding Spring passed Mars, the two bodies came within about 140,000 kilometers (roughly 87,000 miles) of each other. The comet's coma washed over the planet for several hours, with the dense inner coma reaching, or nearly reaching, the surface. Mars was flooded with an invisible tide of charged particles from the coma, and the powerful magnetic field around the comet temporarily merged with – and overwhelmed – the planet's own weak one.

"The main action took place during the comet's closest approach," said Espley, "but the planet's magnetosphere began to feel some effects as soon as it entered the outer edge of the comet's coma."

At first, the changes were subtle. As Mars' magnetosphere, which is normally draped neatly over the planet, started to react to the comet's approach, some regions began to realign to point in different directions. With the comet's advance, these effects built in intensity, almost making the planet's magnetic field flap like a curtain in the wind. By the time of closest approach – when the plasma from the comet was densest – Mars' magnetic field was in complete chaos. Even hours after the comet's departure, some disruption continued to be measured.

Espley and colleagues think the effects of the plasma tide were similar to those of a strong but short-lived solar storm. And like a solar storm, the comet's close passage likely fueled a temporary surge in the amount of gas escaping from Mars' upper atmosphere. Over time, those storms took their toll on the atmosphere.

"With MAVEN, we're trying to understand how the sun and solar wind interact with Mars," said Bruce Jakosky, MAVEN's principal investigator from the University of Colorado's Laboratory for Atmospheric and Space Physics in Boulder. "By looking at how the magnetospheres of the comet and of Mars interact with each other, we're getting a better understanding of the detailed processes that control each one."

This research was published in Geophysical Research Letters.

  Pėrgjigju duke cituar
I vjetėr 16.3.2016, 10:54   7
Anėtarėsuar: 6.2001
Fusha magnetike e Diellit, pėrpilim paraprak nga NASA:

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Picturing the Sun’s Magnetic Field

This illustration lays a depiction of the sun's magnetic fields over an image captured by NASA’s Solar Dynamics Observatory on March 12, 2016. The complex overlay of lines can teach scientists about the ways the sun's magnetism changes in response to the constant movement on and inside the sun. Note how the magnetic fields are densest near the bright spots visible on the sun – which are magnetically strong active regions – and many of the field lines link one active region to another.

This magnetic map was created using the PFSS – Potential Field Source Surface – model, a model of the magnetic field in the sun’s atmosphere based on magnetic measurements of the solar surface. The underlying image was taken in extreme ultraviolet wavelengths of 171 angstroms. This type of light is invisible to our eyes, but is colorized here in gold.

  Pėrgjigju duke cituar
I vjetėr 23.3.2016, 00:58   8
Anėtarėsuar: 6.2001
Agim polar dhe nė Jupiter, studimi i detajuar:

I pėrmbledhur:

Something Weird and Amazing Is Happening at Jupiter's North Pole

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If you were soaring through Jupiter’s turbid skies wearing a pair of x-ray goggles, you might get lucky and witness something incredible. Brilliant flashes of light, more luminous and powerful than the Sun, occurring every 26 minutes and stretching as far as the eye can see. That’s the essence of a massive solar storm recently witnessed for the first time near Jupiter’s north pole.

“When I first saw this, I thought I’d made a mistake,” Will Dunn, a PhD student studying astrophysics at the University College London, told Gizmodo. The northern lights Dunn observed on Jupiter are hundreds of times brighter than the aurora borealis on Earth. “We’re still not sure exactly what’s causing it.”

Jupiter’s northern lights, created when the gas giant’s prodigious magnetic field interacts with charged particles from the Sun, have long fascinated planetary scientists. But after decades of observation, many puzzles remain. Chief among Jupiter’s space weather mysteries is a bright x-ray aurora, located near the planet’s north pole. It never goes away, but since 2006, scientists have watched it brighten and fade every 45 minutes, light a lightbulb on a dimmer switch. Now, Dunn’s observations with the Chandra X-ray observatory and other telescopes have added another twist to this dazzling enigma.

Writing today in the Journal of Geophysical Research, Dunn and his co-authors describe what happened when a coronal mass ejection—a giant cloud of magnetized plasma that erupted from the surface of the Sun—struck the gas giant’s magnetosphere in 2011. When this happens on Earth, we get the northern lights. On Jupiter, the forever-aurora gets bigger and flashier.

“We saw the pulsing get much quicker: it happens about every 26 minutes during a solar storm,” Dunn said. “And we saw a bright enhancement in a region where we’d never seen it before.”

“If your eyes could see x-rays, you’d see something similar to the aurora on Earth,” Dunn continued. “Except the flashing across the the sky would be much bigger and brighter. Jupiter’s auroras cover a region larger than the entire Earth, so it would stretch as far as the eye can see.”

Why Jupiter’s northern lights flicker to a particular tempo, and why that flickering accelerated during the 2011 solar storm, are questions that planetary scientists would love to answer. “We think that when a coronal mass ejection crashes into Jupiter’s magnetosphere, it compresses it by about 2 million kilometers,” Dunn said. But for more details, we may have to wait for NASA’s Juno mission, which reaches the boundary between the Jupiter’s magnetic field and the solar wind this summer.

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In addition to offering yet another mind-blowing glimpse into the meteorological events occurring in our cosmic backyard, Jupiter’s aurora provides a second benchmark for understanding how magnetic fields protect planets from powerful stellar eruptions. And that knowledge may eventually aid in the search for life beyond our solar system.

“We have a pretty good understanding of how the Earth’s magnetosphere works,” Dunn said. “But the universe is filled with magnetically active objects, including billions of exoplanets. Understanding the diversity of magnetic fields has relevance for understanding whether any of those other planets can support life.”

  Pėrgjigju duke cituar
I vjetėr 24.3.2016, 00:03   9
Anėtarėsuar: 6.2001
Kapet blici i njė shpėrthimi yjor, kėtu simulimi:

Caught For The First Time: The Early Flash Of An Exploding Star

The brilliant flash of an exploding star’s shockwave—what astronomers call the “shock breakout”—has been captured for the first time in the optical wavelength or visible light by NASA's planet-hunter, the Kepler space telescope.

An international science team led by Peter Garnavich, an astrophysics professor at the University of Notre Dame in Indiana, analyzed light captured by Kepler every 30 minutes over a three-year period from 500 distant galaxies, searching some 50 trillion stars. They were hunting for signs of massive stellar death explosions known as supernovae.

In 2011, two of these massive stars, called red supergiants, exploded while in Kepler’s view. The first behemoth, KSN 2011a, is nearly 300 times the size of our sun and a mere 700 million light years from Earth. The second, KSN 2011d, is roughly 500 times the size of our sun and around 1.2 billion light years away.

“To put their size into perspective, Earth's orbit about our sun would fit comfortably within these colossal stars,” said Garnavich.

Whether it’s a plane crash, car wreck or supernova, capturing images of sudden, catastrophic events is extremely difficult but tremendously helpful in understanding root cause. Just as widespread deployment of mobile cameras has made forensic videos more common, the steady gaze of Kepler allowed astronomers to see, at last, a supernova shockwave as it reached the surface of a star. The shock breakout itself lasts only about 20 minutes, so catching the flash of energy is an investigative milestone for astronomers.

“In order to see something that happens on timescales of minutes, like a shock breakout, you want to have a camera continuously monitoring the sky,” said Garnavich. “You don’t know when a supernova is going to go off, and Kepler's vigilance allowed us to be a witness as the explosion began.”

Supernovae like these — known as Type II — begin when the internal furnace of a star runs out of nuclear fuel causing its core to collapse as gravity takes over.

The two supernovae matched up well with mathematical models of Type II explosions reinforcing existing theories. But they also revealed what could turn out to be an unexpected variety in the individual details of these cataclysmic stellar events.

While both explosions delivered a similar energetic punch, no shock breakout was seen in the smaller of the supergiants. Scientists think that is likely due to the smaller star being surrounded by gas, perhaps enough to mask the shockwave when it reached the star's surface.

“That is the puzzle of these results,” said Garnavich. “You look at two supernovae and see two different things. That’s maximum diversity.”

Understanding the physics of these violent events allows scientists to better understand how the seeds of chemical complexity and life itself have been scattered in space and time in our Milky Way galaxy

"All heavy elements in the universe come from supernova explosions. For example, all the silver, nickel, and copper in the earth and even in our bodies came from the explosive death throes of stars," said Steve Howell, project scientist for NASA's Kepler and K2 missions at NASA’s Ames Research Center in California's Silicon Valley. "Life exists because of supernovae."

Garnavich is part of a research team known as the Kepler Extragalactic Survey or KEGS. The team is nearly finished mining data from Kepler’s primary mission, which ended in 2013 with the failure of reaction wheels that helped keep the spacecraft steady. However, with the reboot of the Kepler spacecraft as NASA's K2 mission, the team is now combing through more data hunting for supernova events in even more galaxies far, far away.

"While Kepler cracked the door open on observing the development of these spectacular events, K2 will push it wide open observing dozens more supernovae," said Tom Barclay, senior research scientist and director of the Kepler and K2 guest observer office at Ames. "These results are a tantalizing preamble to what's to come from K2!"

In addition to Notre Dame, the KEGS team also includes researchers from the University of Maryland in College Park; the Australian National University in Canberra, Australia; the Space Telescope Science Institute in Baltimore, Maryland; and the University of California, Berkeley.

The research paper reporting this discovery has been accepted for publication in the Astrophysical Journal.

Ames manages the Kepler and K2 missions for NASA’s Science Mission Directorate. NASA's Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

Authored by H. Pat Brennan/JPL and Michele Johnson/Ames

  Pėrgjigju duke cituar
I vjetėr 12.4.2016, 00:05   10
Anėtarėsuar: 6.2001
NASA fillon testmin e teknologjisė pėr lundrim hapėsinor sipas fushave E/M, nga qendra Marshall:

NASA Begins Testing of Revolutionary E-Sail Technology

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Testing has started at NASA’s Marshall Space Flight Center in Huntsville, Alabama, on a concept for a potentially revolutionary propulsion system that could send spacecraft to the edge of our solar system, the heliopause, faster than ever before.

The test results will provide modeling data for the Heliopause Electrostatic Rapid Transit System (HERTS). The proposed HERTS E-Sail concept, a propellant-less propulsion system, would harness solar wind to travel into interstellar space.

“The sun releases protons and electrons into the solar wind at very high speeds -- 400 to 750 kilometers per second,” said Bruce Wiegmann an engineer in Marshall’s Advanced Concepts Office and the principal investigator for the HERTS E-Sail. “The E-Sail would use these protons to propel the spacecraft.”

Extending outward from the center of the spacecraft, 10 to 20 electrically charged, bare aluminum wires would produce a large, circular E-Sail that would electrostatically repel the fast moving protons of the solar wind. The momentum exchange produced as the protons are repelled by the positively charged wires would create the spacecraft’s thrust. Each tether is extremely thin, only 1 millimeter -- the width of a standard paperclip -- and very long, nearly 12 and a half miles -- almost 219 football fields. As the spacecraft slowly rotates at one revolution per hour, centrifugal forces will stretch the tethers into position.

The testing, which is taking place in the High Intensity Solar Environment Test system, is designed to examine the rate of proton and electron collisions with a positively charged wire. Within a controlled plasma chamber simulating plasma in a space, the team is using a stainless steel wire as an analog for the lightweight aluminum wire. Though denser than aluminum, stainless steel’s non-corrosive properties will mimic that of aluminum in space and allow more testing with no degradation.

Engineers are measuring deflections of protons from the energized charged wire within the chamber to improve modeling data that will be scaled up and applied to future development of E-Sail technology. The tests are also measuring the amount of electrons attracted to the wire. This information will be used to develop the specifications for the required electron gun, or an electron emitter, that will expel excess electrons from the spacecraft to maintain the wire’s positive voltage bias, which is critical to its operation as a propulsion system.

This concept builds upon the electric sail invention of Dr. Pekka Janhunen of the Finnish Meteorological Institute, and the current technologies required for an E-Sail integrated propulsion system are at a low technology readiness level. If the results from plasma testing, modeling, and wire deployer investigations prove promising after the current two-year investigation, there is still a great deal of work necessary to design and build this new type of propulsion system. The earliest actual use of the technology is probably at least a decade away.

The HERTS E-Sail concept is being studied in response to the National Academy of Science’s 2012 Heliophysics Decadal Survey, a study conducted by experts from NASA, industry, academia and government agencies, that identified advanced propulsion as the main technical hurdle for future exploration of the heliosphere. The survey, which offered the agency a road map of the heliophysics community’s priorities for 2013-2022, highlighted the need for propulsion systems that could reach the edge of our solar system significantly faster than in the past.

To send a scientific probe on a deep space journey, the sail would have to have a large effective area. Space travel is generally measured in astronomical units, or the distance from Earth to the sun. At 1 AU, the E-Sail would have an effective area of about 232 square miles, slightly smaller than the city of Chicago. The effective area would increase to more than 463 square miles-- similar to Los Angeles -- at 5 AU.

This increase in area would lead to continued acceleration much longer than comparable propulsion technologies. For example, when solar sail spacecraft reach the asteroid belt at 5 AU, the energy of the solar photons dissipates and acceleration stops. Wiegmann believes the E-Sail would continue to accelerate well beyond that.

“The same concerns don’t apply to the protons in the solar wind,” he said. “With the continuous flow of protons, and the increased area, the E-Sail will continue to accelerate to 16-20 AU -- at least three times farther than the solar sail. This will create much higher speeds.”

In 2012, NASA’s Voyager 1 became the first spacecraft to ever cross the heliopause and reach interstellar space. Launched in 1977, Voyager 1 took almost 35 years to make its 121 AU journey. The goal of HERTS is to develop an E-Sail that could make the same journey in less than one-third that time.

“Our investigation has shown that an interstellar probe mission propelled by an E-Sail could travel to the heliopause in just under 10 years,” he said. “This could revolutionize the scientific returns of these types of missions.”

The HERTS E-Sail concept development and testing is funded by NASA’s Space Technology Mission Directorate through the NASA Innovative Advanced Concepts Program, which encourages visionary ideas that could transform future missions with the creation of radically better or entirely new aerospace concepts. NIAC projects study innovative, technically credible, advanced concepts that could one day "change the possible" in aerospace.

Selected as a Phase II NIAC Fellow in 2015, the HERTS team was awarded an additional $500,000 to further test the E-Sail and possibly change not only the way NASA travels to the heliopause, but also within our solar system.

“As the team studied this concept, it became clear that the design is flexible and adaptable,” said Wiegmann. “Mission and vehicle designers can trade off wire length, number of wires and voltage levels to fit their needs -- inner planetary, outer planetary or heliopause. The E-Sail is very scalable.”

Steering can be accomplished by modulating the wire’s voltage individually as the spacecraft rotates. Affecting a difference in force applied on different portions of the E-Sail, would give engineers the ability to steer the spacecraft, similar to the sails of a boat.

For more information on the Heliopause Electrostatic Rapid Transit System, visit:


For more information on the NASA Innovative Advanced Concepts Program, visit:


Tracy McMahan
Marshall Space Flight Center, Huntsville, Alabama

Kimberly Newton
Marshall Space Flight Center, Huntsville, Alabama

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Within a controlled plasma chamber -- the High Intensity Solar Environment Test system -- tests will examine the rate of proton and electron collisions with a positively charged tether. Results will help improve modeling data that will be applied to future development of E-Sail technology concept.
  Pėrgjigju duke cituar
I vjetėr 6.5.2016, 00:37   11
Anėtarėsuar: 6.2001
Njė studim i fundit i NASA-s mbi Plutonin flet pėr lidhje magnetike brenda sistemit diellor e pėrtej, duke u "habitur" sėrish me realitetin elektromagnetik qė nuk parashikohet nga modeli standard:

Pluto’s Interaction with the Solar Wind is Unique, Study Finds

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Pluto behaves less like a comet than expected and somewhat more like a planet like Mars or Venus in the way it interacts with the solar wind, a continuous stream of charged particles from the sun.

This is according to the first analysis of Pluto’s interaction with the solar wind, funded by NASA’s New Horizons mission and published today in the Journal of Geophysical Research – Space Physics by the American Geophysical Union (AGU).

Using data from the Solar Wind Around Pluto (SWAP) instrument from the New Horizons July 2015 flyby, scientists have for the first time observed the material coming off of Pluto’s atmosphere and studied how it interacts with the solar wind, leading to yet another “Pluto surprise.”

“This is a type of interaction we’ve never seen before anywhere in our solar system,” said David J. McComas, lead author of the study. McComas, professor of astrophysical sciences at Princeton University and vice president for the Princeton Plasma Physics Laboratory. “The results are astonishing.” McComas leads the SWAP instrument aboard New Horizons; he also led the development of SWAP when he was at the Southwest Research Institute (SwRI) in San Antonio, Texas.

Space physicists say that they now have a treasure trove of information about how Pluto’s atmosphere interacts with the solar wind. Solar wind is the plasma that spews from the sun into the solar system at a supersonic 100 million miles per hour (160 million kilometers per hour), bathing planets, asteroids, comets and interplanetary space in a soup of mostly protons and electrons.

Previously, most researchers thought that Pluto was characterized more like a comet, which has a large region of gentle slowing of the solar wind, as opposed to the abrupt diversion solar wind encounters at a planet like Mars or Venus. Instead, like a car that’s part gas- and part battery-powered, Pluto is a hybrid, researchers say.

So Pluto continues to confound. “These results speak to the power of exploration. Once again we’ve gone to a new kind of place and found ourselves discovering entirely new kinds of expressions in nature,” said SwRI’s Alan Stern, New Horizons principal investigator.

Since it’s so far from the sun – an average of about 3.7 billion miles, the farthest planet in the solar system – and because it’s the smallest, scientists thought Pluto’s gravity would not be strong enough to hold heavy ions in its extended atmosphere. But, “Pluto’s gravity clearly is enough to keep material relatively confined,” McComas said.

The researchers were able to separate the heavy ions of methane, the main gas escaping from Pluto’s atmosphere, from the light ions of hydrogen that come from the sun using the SWAP instrument.

Among additional Pluto findings:

Like Earth, Pluto has a long ion tail, that extends downwind at least a distance of about 100 Pluto radii (73,800 miles/118,700 kilometers, almost three times the circumference of Earth), loaded with heavy ions from the atmosphere and with “considerable structure.”
Pluto’s obstruction of the solar wind upwind of the planet is smaller than had been thought. The solar wind isn’t blocked until about the distance of a couple planetary radii (1,844 miles/3,000 kilometers, about the distance between Chicago and Los Angeles.)
Pluto has a very thin boundary of Pluto’s tail of heavy ions and the sheath of the shocked solar wind that presents an obstacle to its flow.

Heather Elliott, astrophysicist at SwRI and co-author on the paper, notes, “Comparing the solar wind-Pluto interaction to the solar wind-interaction for other planets and bodies is interesting because the physical conditions are different for each, and the dominant physical processes depend on those conditions.”

These findings offer clues to the magnetized plasmas that one might find around other stars, said McComas. “The range of interaction with the solar wind is quite diverse, and this gives some comparison to help us better understand the connections in our solar system and beyond.”

  Pėrgjigju duke cituar
I vjetėr 13.5.2016, 23:26   12
Anėtarėsuar: 6.2001
NASA ka filluar nga vjet njė ndryshim gradual tė paradigmės drejt modelit elektromagnetik. Mė e fundit nė radhė ėshtė dhe kjo video nga qendra Goddard, qė praktikisht pohon ēfarė kanė thėnė mbėshtetėsit e modelit elektromagnetik prej shumė vitesh tashmė:

This short video outlines the MMS mission and its first results. Since it launched, MMS has made more than 4,000 trips through the magnetic boundaries around Earth, each time gathering information about the way the magnetic fields and particles move. A surprising result was that at the moment of interconnection between the sun’s magnetic field lines and those of Earth the crescents turned abruptly so that the electrons flowed along the field lines. By watching these electron tracers, MMS made the first observation of the predicted breaking and interconnection of magnetic fields in space.

  Pėrgjigju duke cituar
I vjetėr 20.5.2016, 17:54   13
Anėtarėsuar: 6.2001
Vrojtime tė reja nga sondat e NASA-s evidentojė se njė "unazė" rryme elektrike rrethon tokėn dhe janė ende duke analizuar dukurinė:

NASA’s Van Allen probes reveal long-term behavior of Earth’s ring current

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New findings based on a year's worth of observations from NASA's Van Allen Probes have revealed that the ring current -- an electrical current carried by energetic ions that encircles our planet -- behaves in a much different way than previously understood.

The ring current has long been thought to wax and wane over time, but the new observations show that this is true of only some of the particles, while other particles are present consistently. Using data gathered by the Radiation Belt Storm Probes Ion Composition Experiment, or RBSPICE, on one of the Van Allen Probes, researchers have determined that the high-energy protons in the ring current change in a completely different way from the current's low-energy protons. Such information can help adjust our understanding and models of the ring current -- which is a key part of the space environment around Earth that can affect our satellites.

The findings were published in Geophysical Research Letters. "We study the ring current because, for one thing, it drives a global system of electrical currents both in space and on Earth's surface, which during intense geomagnetic storms can cause severe damages to our technological systems," said lead author of the study Matina Gkioulidou, a space physicist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. "It also modifies the magnetic field in the near-Earth space, which in turn controls the motion of the radiation belt particles that surround our planet. That means that understanding the dynamics of the ring current really matters in helping us understand how radiation belts evolve as well."

The ring current lies at a distance of approximately 6,200 to 37,000 miles (10,000 to 60,000 km) from Earth. The ring current was hypothesized in the early 20th century to explain observed global decreases in the Earth's surface magnetic field, which can be measured by ground magnetometers. Such changes of the ground magnetic field are described by what's called the Sym-H index. "Previously, the state of the ring current had been inferred from the variations of the Sym-H index, but as it turns out, those variations represent the dynamics of only the low-energy protons," said Gkioulidou. "When we looked at the high-energy proton data from the RBSPICE instrument, however, we saw that they were behaving in a very different way, and the two populations told very different stories about the ring current."

The Van Allen Probes, launched in 2012, offer scientists the first chance in recent history to continuously monitor the ring current with instruments that can observe ions with an extremely wide range of energies. The RBSPICE instrument has captured detailed data of all types of these energetic ions for several years. "We needed to have an instrument that measures the broad energy range of the particles that carry the ring current, within the ring current itself, for a long period of time," Gkioulidou said. A period of one year from one of the probes was used for the team's research.

"After looking at one year of continuous ion data it became clear to us that there is a substantial, persistent ring current around the Earth even during non-storm times, which is carried by high-energy protons. During geomagnetic storms, the enhancement of the ring current is due to new, low-energy protons entering the near-Earth region. So trying to predict the storm-time ring current enhancement while ignoring the substantial pre-existing current is like trying to describe an elephant after seeing only its feet," Gkioulidou said.

The Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, built and operates the Van Allen Probes for NASA's Science Mission Directorate. RBSPICE is operated by the New Jersey Institute of Technology in Newark, New Jersey. The mission is the second mission in NASA's Living With a Star program, managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland.

  Pėrgjigju duke cituar
I vjetėr 21.5.2016, 10:35   14
Anėtarėsuar: 6.2001
Researchers in Antarctic discover new facets of space weather

A team of National Science Foundation (NSF)-supported researchers at the Virginia Polytechnic Institute and State University (Virginia Tech) discovered new evidence about how Earth's magnetic field interacts with solar wind, almost as soon as they finished installing six data-collection stations across East Antarctic Plateau last January.

Their findings could have significant effects on our understanding of space weather. Although invisible to the naked eye, space weather can have serious, detrimental effects on modern technological infrastructure, including telecommunications, navigation, and electrical power systems.

The researchers for the first time observed that regardless of the hemisphere or the season, the polar ionosphere is subject to a constant electrical current, produced by pressure changes in the solar wind.

"This finding is a new part of the physics that we need to understand and work with," said Robert Clauer, a professor in Virginia Tech's Bradley Department of Electrical and Computer Engineering. "It's a bit of a surprise, because when you have a current, you usually expect a voltage relationship, where resistance and current are inversely related -- high resistance equals small current; low resistance equals large current."

These space weather observations allow researchers to watch how the behavior of the sun and the solar wind -- an unbroken supersonic flow of charged particles from the sun -- changes over time and how Earth's magnetic field responds to solar wind variations. The observations help build a detailed, reliable model of space weather.

They hope that eventually space weather forecasting will become as reliable as today's winter storm warnings.

The project to develop and deploy these autonomous data-collection stations in the Antarctic, funded by a $2.7 million NSF award, has progressed over a seven-year period. NSF manages the U.S. Antarctic Program, through which it supports researchers nationwide, provides logistical support to the research and operates three year-round stations in Antarctica.

Clauer and his team designed and hand-built six autonomous data-collection stations and installed them piece-by-piece near the geographic South Pole for initial testing. Following successful testing, the autonomous data-collection stations were placed along the 40-degree magnetic meridian (longitude), deep in the southern polar cap areas under the auroras. The stations, located in the harsh environment of the remote East Antarctic Plateau, are the Southern Hemisphere counterpart to a magnetically similar chain in Greenland.

Clauer and his Magnetosphere-Ionosphere Science team have been monitoring the electric current systems in the magnetosphere -- specifically currents that connect to the ionosphere. During the summer in the Northern Hemisphere, there is more direct sunlight on the atmosphere, which means more atoms are ionized. This phenomenon creates a highly conductive ionosphere in the summer months and a poorly conductive one in the winter.

"The solar wind interacts with Earth's magnetic field in a manner similar to a fluid, but an electrically conducting fluid," Clauer said.

A chain of data-collection stations in Greenland allowed researchers to take measurements in the Northern Hemisphere. Until recently, these data were divided into summer and winter, and the information gathered during the winter months was used to approximate what was happening in the Southern Hemisphere during the northern summer.

"We didn't have a full picture of what was happening in the space environment because we could only observe one hemisphere, but magnetic field lines are connected to both hemispheres," said Clauer. "It was important that we look at them simultaneously."

The stations run autonomously and are powered by solar cells in the months-long Antarctic summer, and by lead-acid batteries during winter. The stations contain a collection of instruments, including a dual-frequency GPS receiver that tracks signal changes produced by density irregularities in the ionosphere, and two kinds of magnetometers that measure the varying strength and direction of magnetic fields. The data is transmitted to Blacksburg, Virginia, via Iridium satellites.

Clauer's team will continue collecting information from both sets of data stations. They hope to operate throughout the 11-year solar activity cycle, depending on snow accumulation.

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Merr pjesė nė diskutim

Ora nė Shqipėri ėshtė 05:03.

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