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  • richardmitnick 9:46 am on July 19, 2018 Permalink | Reply
    Tags: NASA STEREO, , Occulting disc, , , ,   

    From Southwest Research Institute via Science Alert: “Never-Before-Seen Structures Have Been Detected in Our Sun’s Corona” 

    SwRI bloc

    From Southwest Research Institute

    via

    ScienceAlert

    Science Alert

    19 JUL 2018
    MICHELLE STARR

    1
    DeForest et al./The Astrophysical Journal

    Using longer exposures and sophisticated processing techniques, scientists have taken extraordinarily high-fidelity pictures of the Sun’s outer atmosphere – what we call the corona – and discovered fine details that have never been detected before.

    The Sun is a complex object, and with the soon-to-be-launched Parker Solar Probe we’re on the verge of learning so much more about it.

    NASA Parker Solar Probe Plus

    But there’s still a lot we can do with our current technology, as scientists from the Southwest Research Institute (SwRI) have just demonstrated.

    The team used the COR-2 coronagraph instrument on NASA’s Solar and Terrestrial Relations Observatory-A (STEREO-A) to study details in the Sun’s outer atmosphere.

    NASA/STEREO spacecraft

    This instrument takes images of the atmosphere by using what is known as an occulting disc – a disc placed in front of the lens that blocks out the actual Sun from the image, and therefore the light that would overwhelm the fine details in the plasma of the Sun’s atmosphere.

    The corona is extremely hot, much hotter than the inner photosphere’s 5,800 Kelvin, coming in at between 1 and 3 million Kelvin. It’s also the source of solar wind – the constant stream of charged particles that flows out from the Sun in all directions.

    When measurements of the solar wind are taken near Earth, the magnetic fields embedded therein are complex and interwoven, but it’s unclear when this turbulence occurs.

    “In deep space, the solar wind is turbulent and gusty,” says solar physicist Craig DeForest of the SwRI.

    “But how did it get that way? Did it leave the Sun smooth, and become turbulent as it crossed the solar system, or are the gusts telling us about the Sun itself?”

    If the turbulence was occurring at the source of the solar wind – the Sun – then we should have been able to see complex structures in the corona as the cause of it, but previous observations showed no such structures.

    Instead, they showed the corona as a smooth, laminar structure. Except, as it turns out, that wasn’t the case. The structures were there, but we hadn’t been able to obtain a high enough image resolution to see them.

    2
    NASA/SwRI/STEREO

    “Using new techniques to improve image fidelity, we realised that the corona is not smooth, but structured and dynamic,” DeForest explains. “Every structure that we thought we understood turns out to be made of smaller ones, and to be more dynamic than we thought.”

    To obtain the images, the research team ran a special three-day campaign wherein the instrument took more frequent and longer-exposure images than it usually does, allowing more time for light from faint sources to be detected by the coronagraph. But that was only part of the process.

    Although the occulting disc does a great job at filtering out the bright light from the Sun, there’s still a great deal of noise in the resulting images, both from the surrounding space and the instrument.

    Obviously, since STEREO-A is in space, altering the hardware isn’t an option, so DeForest and his team worked out a technique for identifying and removing that noise, vastly improving the data’s signal-to-noise ratio.

    They developed new filtering algorithms to separate the corona from noise, and adjust brightness. And, perhaps more challengingly, correct for the blur caused by the motion of the solar wind.

    They discovered that the coronal loops known as streamers – which can erupt into the coronal mass ejections that send plasma and particles shooting out into space – are not one single structure.

    “There is no such thing as a single streamer,” DeForest said. “The streamers themselves are composed of myriad fine strands that, together, average to produce a brighter feature.”

    They also found there’s no such thing as the Alfvén surface – a theoretical, sheet-like boundary where the solar wind starts moving forward faster than waves can travel backwards through it, and it disconnects from the Sun, moving beyond its influence.

    Instead, DeForest said, “There’s a wide ‘no-man’s land’ or ‘Alfvén zone’ where the solar wind gradually disconnects from the Sun, rather than a single clear boundary.”

    But the research also presented a new mystery to probe, as well. At a distance of about 10 solar radii the solar wind suddenly changes character. But it returns to normal farther out from the Sun, indicating that there’s some interesting physics happening at 10 solar radii.

    Figuring out what that is may require some help from Parker, for which this research is key. Parker is due to launch in August.

    Meanwhile, the team’s research has been published in The Astrophysical Journal.

    See the full article here .

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    SwRI Campus

    Southwest Research Institute (SwRI) is an independent, nonprofit applied research and development organization. The staff of nearly 2,800 specializes in the creation and transfer of technology in engineering and the physical sciences. SwRI’s technical divisions offer a wide range of technical expertise and services in such areas as engine design and development, emissions certification testing, fuels and lubricants evaluation, chemistry, space science, nondestructive evaluation, automation, mechanical engineering, electronics, and more.

     
  • richardmitnick 4:30 pm on May 8, 2017 Permalink | Reply
    Tags: Berkeley, , , , NASA STEREO, , Space Sciences Laboratory at University of California   

    From Goddard: “Space Weather Model Simulates Solar Storms From Nowhere” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    May 8, 2017
    Lina Tran
    kathalina.k.tran@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    Our ever-changing sun continuously shoots solar material into space. The grandest such events are massive clouds that erupt from the sun, called coronal mass ejections, or CMEs. These solar storms often come first with some kind of warning — the bright flash of a flare, a burst of heat or a flurry of solar energetic particles. But another kind of storm has puzzled scientists for its lack of typical warning signs: They seem to come from nowhere, and scientists call them stealth CMEs.

    Now, an international team of scientists, led by the Space Sciences Laboratory at University of California, Berkeley, and funded in part by NASA, has developed a model that simulates the evolution of these stealthy solar storms.


    SSL UC Berkeley campus


    Space Science Labs UC Berkeley

    The scientists relied upon NASA missions STEREO and SOHO for this work, fine-tuning their model until the simulations matched the space-based observations.

    NASA/STEREO spacecraft


    ESA/NASA SOHO

    Their work shows how a slow, quiet process can unexpectedly create a twisted mass of magnetic fields on the sun, which then pinches off and speeds out into space — all without any advance warning.

    1
    Watch the evolution of a stealth CME in this simulation. Differential rotation creates a twisted mass of magnetic fields on the sun, which then pinches off and speeds out into space. The image of the sun is from NASA’s STEREO. Colored lines depict magnetic field lines, and the different colors indicate in which layers of the sun’s atmosphere they originate. The white lines become stressed and form a coil, eventually erupting from the sun. Credits: NASA’s Goddard Space Flight Center/ARMS/Joy Ng, producer

    Compared to typical CMEs, which erupt from the sun as fast as 1800 miles per second, stealth CMEs move at a rambling gait — between 250 to 435 miles per second. That’s roughly the speed of the more common solar wind, the constant stream of charged particles that flows from the sun. At that speed, stealth CMEs aren’t typically powerful enough to drive major space weather events, but because of their internal magnetic structure they can still cause minor to moderate disturbances to Earth’s magnetic field.

    To uncover the origins of stealth CMEs, the scientists developed a model of the sun’s magnetic fields, simulating their strength and movement in the sun’s atmosphere. Central to the model was the sun’s differential rotation, meaning different points on the sun rotate at different speeds. Unlike Earth, which rotates as a solid body, the sun rotates faster at the equator than it does at its poles.

    The model showed differential rotation causes the sun’s magnetic fields to stretch and spread at different rates. The scientists demonstrated this constant process generates enough energy to form stealth CMEs over the course of roughly two weeks. The sun’s rotation increasingly stresses magnetic field lines over time, eventually warping them into a strained coil of energy. When enough tension builds, the coil expands and pinches off into a massive bubble of twisted magnetic fields — and without warning — the stealth CME quietly leaves the sun.

    Such computer models can help researchers better understand how the sun affects near-Earth space, and potentially improve our ability to predict space weather, as is done for the nation by the U.S. National Oceanic and Atmospheric Administration. A paper published in the Journal of Geophysical Research on Nov. 5, 2016, summarizes this work.

    Related

    New Space Weather Model Helps Simulate Magnetic Structure of Solar Storms
    NASA Scientists Demonstrate Technique to Improve Particle Warnings that Protect Astronauts

    See the full article here.

    Please help promote STEM in your local schools.

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    Stem Education Coalition

    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.


    NASA/Goddard Campus

     
  • richardmitnick 3:04 pm on October 25, 2016 Permalink | Reply
    Tags: , , NASA STEREO, , STEREO: 10 Years of Revolutionary Solar Views   

    From Goddard: “STEREO: 10 Years of Revolutionary Solar Views” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    Oct. 25, 2016
    Sarah Frazier
    sarah.frazier@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    1
    No image caption. No image credit.

    Launched 10 years ago, on Oct. 25, 2006, the twin spacecraft of NASA’s STEREO mission – short for Solar and Terrestrial Relations Observatory – have given us unprecedented views of the sun, including the first-ever simultaneous view of the entire star at once.

    NASA/STEREO spacecraft
    NASA/STEREO spacecraft

    This kind of comprehensive data is key to understanding how the sun erupts with things like coronal mass ejections and energetic particles, as well as how those events move through space, sometimes impacting Earth and other worlds. Ten years ago, the twin STEREO spacecraft joined a fleet of NASA spacecraft monitoring the sun and its influence on Earth and space – and they provided a new and unique perspective.


    Access mp4 video here .
    Credits: NASA’s Goddard Space Flight Center/Genna Duberstein, producer

    The two STEREO observatories, called STEREO-A and STEREO-B – for Ahead and Behind, respectively – were sent out from Earth in opposite directions. Using gravitational assists from both the moon and Earth, the STEREO spacecraft were accelerated to Earth-escape velocities. STEREO-A was inserted into an orbit slightly smaller, and therefore faster, than Earth’s. For STEREO-B, the reverse happened: It was nudged into an orbit slightly larger than Earth’s so that it traveled around the sun more slowly, falling increasingly behind the Earth. As the spacecraft slowly fanned out away from the centerline between Earth and the sun – where every other sun-watching spacecraft is located – they revealed more and more new information about our closest star.

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    This composite view shows the sun as it appeared on Jan. 31, 2011, with simultaneous views from both of NASA’s STEREO spacecraft and NASA’s Solar Dynamics Observatory. These three distinct viewpoints allowed scientists to capture almost the entire sun at once, with only a small gap in data.
    Credits: NASA/Goddard/STEREO

    “STEREO gives us a much more thorough view of the sun, solar wind and solar activity,” said Terry Kucera, deputy project scientist for STEREO at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “The view from the far side of the sun lets us record more events and get more complete pictures of each event.”

    When observed through a solar telescope, the surface of the sun can be seen to be churning with near-constant activity, sometimes including the larger solar eruptions that can influence Earth, other worlds, and space itself. We call these changing conditions space weather. On Earth, space weather often manifests as auroras, or – in extreme cases – damage to satellites or stress on power grids.

    The prime STEREO mission was designed for two years of operations, observing the sun and the space environment around it, by which point the spacecraft would have traveled about 45 degrees (one-eighth of a circle each) away from Earth. This mission design was revolutionary, since our observations of the sun and conditions in space had previously been confined to views only from Earth’s perspective. By providing us with different views of the sun simultaneously, STEREO helped scientists watch solar eruptions develop over time, and gave them multiple perspectives of how those eruptions propagate outward. The greater the separation of the two spacecraft from each other and from Earth, the more we learned about the sun and its influence on space – including multi-point views of one of the most powerful solar storms on record.

    3
    This animation shows the orbits of the two STEREO spacecraft from October 2006 to October 2016. Because of the twin probes’ unique positions in space, the STEREO mission has given scientists an unprecedented look at the sun, helping us to understand our home star. Credits: NASA Goddard’s Scientific Visualization Studio

    “STEREO had unique perspectives of a powerful CME on July 2012, which was strong enough to cause serious disruptions if it had been Earth-directed,” said Joe Gurman, STEREO project scientist at Goddard. “We got a head-on look with STEREO-A, a side view with STEREO-B as well as observations by Earth-orbiting satellites.”

    However, STEREO’s real windfall is the sheer amount of data collected. Both spacecraft functioned well for nearly eight years, yielding a treasure trove of data on solar events.

    “Real science doesn’t come from just one event,” said Gurman. “The biggest advantage of STEREO is being able to validate our models of how CMEs move through space.”

    STEREO-A continues to collect data. However, STEREO-B encountered an issue when the spacecraft approached a phase called superior conjunction – when the sun would stand between the spacecraft and Earth, blocking all communications. During testing in October 2014 to prepare for superior conjunction, contact with STEREO-B was lost. After nearly two years, on Aug. 21, 2016, mission operators managed to contact STEREO-B once again, and have been in touch intermittently since then. This contact has revealed new information about the spacecraft’s battery and charge state, its position in space, its speed and its spin – and mission operators continue to attempt recovery.

    “The challenges for a successful recovery are many,” said Dan Ossing, the STEREO mission operations manager at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. “It’s an incremental process that continues to evolve, and could take months or even years. But we know enough of the spacecraft has survived to make these recovery attempts worthwhile. We just have to be patient.”

    Though STEREO-A was silent for nearly four months because of superior conjunction, after contact was re-established it returned the data recorded on the sun’s far side, filling in this gap in the timeline of solar data. The STEREO-A spacecraft is now operating fully, maintaining this stream of information.

    “It’s these long term measurements that are critical for understanding the sun,” said Gurman.

    STEREO is the third mission in NASA’s Solar Terrestrial Probes program, which is managed by NASA Goddard for NASA’s Science Mission Directorate in Washington. It was built by the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

    Related Link

    NASA’s STEREO website

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.
    NASA Goddard campus
    NASA/Goddard Campus
    NASA image

     
  • richardmitnick 7:28 am on October 18, 2016 Permalink | Reply
    Tags: , , NASA STEREO,   

    From Goddard: “Wayward Field Lines Challenge Solar Radiation Models” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    Oct. 17, 2016
    Lina Tran
    kathalina.k.tran@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    In addition to the constant emission of warmth and light, our sun sends out occasional bursts of solar radiation that propel high-energy particles toward Earth. These solar energetic particles, or SEPs, can impact astronauts or satellites. To fully understand these particles, scientists must look to their source: the bursts of solar radiation.

    But scientists aren’t exactly sure which of the two main features of solar eruptions –narrow solar flares or wide coronal mass ejections – causes the SEPs during different bursts. Scientists try to distinguish between the two possibilities by using observations, and computer models based on those observations, to map out where the particles could be found as they spread out and traveled away from the sun. NASA missions STEREO and SOHO collect the data upon which these models are built.

    NASA/STEREO spacecraft
    NASA/STEREO spacecraft

    ESA/NASA SOHO
    ESA/NASA SOHO

    Sometimes, these solar observatories saw SEPs on the opposite side of the sun than where the eruption took place. What kind of explosion on the sun could send the particles so far they ended up behind where they started?


    Access mp4 video here .
    This video compares the two models for particle distribution over the course of just three hours after an SEP event. The white line represents a magnetic field line, the general path that the SEPs follow. The line starts at an SEP event at the sun, and leads the particles in a spiral around the sun. The animation of the updated model, on the right, depicts a static field line, but as the SEPs travel farther in space, turbulent solar material causes wandering field lines. In turn, wandering field lines cause the particles to spread much more efficiently than the traditional model, on the left, predicted. Credits: NASA’s Goddard Space Flight Center/UCLan/Stanford/ULB/Joy Ng, producer

    Now a new model has been developed by an international team of scientists, led by the University of Central Lancashire and funded in part by NASA. The new model shows how particles could travel to the back of the sun no matter what type of event first propelled them. Previous models assumed the particles mainly follow the average of magnetic field lines in space on their way from the sun to Earth, and slowly spread across the average over time. The average field line forms a steady path following a distinct spiral because of the sun’s rotation. But the new model takes into consideration that magnetic fields lines can wander – a result of turbulence in solar material as it travels away from the sun.

    With this added information, models now show SEPs spiraling out much wider and farther than previous models predicted – explaining how SEPs find their way to even the far side of the sun. Understanding the nature of SEP distribution helps scientists as they continue to map out the origins of these high-energy particles. A paper published in Astronomy and Astrophysics on June 6, 2016, summarizes the research, a result of collaboration between the University of Central Lancashire, Université Libre de Bruxelles, University of Waikato and Stanford University.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.
    NASA Goddard campus
    NASA/Goddard Campus
    NASA image

     
  • richardmitnick 11:24 am on August 26, 2016 Permalink | Reply
    Tags: , , , NASA STEREO,   

    From Ethan Siegel: “NASA’s Revived STEREO-B Could Save Us From A Trillion Dollar Disaster” 

    From Ethan Siegel

    Aug 26, 2016

    1
    An X-class solar flare erupted from the Sun’s surface in 2012. At the time, it was the largest flare in five years. Image credit: NASA/Solar Dynamics Observatory (SDO) via Getty Images.

    Solar flares are spectacular sights from space, where giant streams of plasma are ejected from the Sun’s interior at incredibly high energies and speeds. They stream through the Solar System, usually traveling the Sun-Earth distance in three days or fewer. While this intense, ionized radiation would be dangerous to an astronaut in the depths of space, for the most part our planet’s magnetic field and atmosphere shields our bodies from any harm. The magnetic field funnels the radiation away from Earth, only enabling it to strike in a region around the poles, while the atmosphere ensures that the charged particles themselves don’t make it down to the surface. But their changing magnetic fields do, and that’s enough to induce currents in electrical wires, circuits and loops. Thankfully, now that NASA’s STEREO-A and STEREO-B spacecraft are both alive simultaneously, we’ll get the earliest warnings possible if a potential catastrophe is headed our way.

    NASA/STEREO spacecraft
    NASA/STEREO spacecraft

    You might think this is a rare event, but it’s not at all rare like a meteor striking Earth is rare. It’s not even “rare” in the sense that seeing a supernova from Earth is rare; an ultra-high-energy solar flare directed right at Earth is a question of when, not if. Imagine a beautiful, clear day. The Sun is shining, the skies are clear, and you couldn’t ask for a nicer day. All of a sudden, the Sun itself appears to brighten, just for a brief amount of time, like it released an extra burst of energy. That night, some 17 hours later, the most spectacular auroral display ever brightens the night in a way you never imagined.

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    Sunspots are often, but not always, portents of where a solar flare is most likely to occur. Image credit: Shahrin Ahmad (ShahGazer), Kuala Lumpur, Malaysia.

    Workers across the United States awaken at 1 a.m., because the sky is as bright as the dawn. Aurorae illuminate the skies as far south as the Caribbean, beneath the Tropic of Cancer. And long, electricity-carrying wires spark, start fires and even operate and send signals when there’s no electricity! This even includes, believe it or not, when they aren’t plugged in. This isn’t a science-fiction scenario; this is history. This is what a catastrophic Solar Storm looks like, and this actually occurred exactly as described in 1859.

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    A significant coronal mass ejection from the Sun that (thankfully) was not directed at Earth. Image credit: NASA / GSFC / SDO.

    NASA/SDO
    NASA/SDO

    The way this actually happens is that the Sun, rather than being this constant ball of nuclear fire in the sky, has an active surface, complete with an intricate magnetic structure, temperature variations, sunspots, and occasional flares and mass ejections. For reasons we don’t completely understand, the Sun’s activity levels ebb and peak on an 11-year timescale known as the Solar Cycle, and the transition between 2013/2014 was anticipated to have been the peak of our current cycle. We’re more likely to see larger numbers of flares, as well as stronger-than-average flares, during the peak years, but in reality they can occur at any time.

    Typically (but not always), these flares pose no danger to anything here on Earth, for a variety of reasons.

    1.) Most solar flares are not directed anywhere near the Earth. Space is a big place, and even at our relatively close distance of 93 million miles (or 150 million km) from the Sun, that’s a long way away. Even though most sunspots occur near the solar equator, more than 95% of flares and ejections, when they occur, never impact our planet at all. But there is that pesky few percent that does impact us.

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    A representation of how most ionized particles are diverted away from Earth by our magnetic field. Image credit: NASA.

    Magnetosphere of Earth, original bitmap from NASA. SVG rendering by Aaron Kaase
    Magnetosphere of Earth, original bitmap from NASA. SVG rendering by Aaron Kaase

    2.) Most flares are too small, too slow and sub-optimally aligned to get past the Earth’s magnetic field. Our magnetic field is awesome! Sure, it might be less than 1 G (gauss) at the surface (or 0.0001 T — for Tesla — for you mks sticklers out there), barely enough to deflect your compass needles towards the magnetic poles. But the field extends far into space, and the matter ejected in a solar flare are almost exclusively charged particles, which typically move at speeds of only a million miles an hour.

    These particles are bent by our magnetic field (as are all charged particles moving through a magnetic field) and will mostly be deflected away from the Earth. The ones that are bent into the Earth will crash into our upper atmosphere; this is the cause of nearly all auroral events.

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    The atmospheric effects of the aurorae, as seen from space. Image credit: NASA / ISS expedition crew 23.

    3.) Our atmosphere is sufficiently thick to prevent these charged particles from irradiating us. Even if the flare moves quickly (or at about five million miles-per-hour), is huge (containing billions of tons of matter), and is aimed directly at us, the charged particles will never make it through our atmosphere, down to the surface. In fact, they peter out to practically nothing nearly 50 km above the Earth’s surface, far higher than any mountains or even that the heights airliners reach. Unless you’re in space (for some reason) at the time, you won’t receive any more radiation than you normally would, and there is no biological risk.

    But there is one real risk, and it’s a consequence of our physical laws of electromagnetism.

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    The anatomy of the dangers of a solar flare. Image credit: NASA.

    A charged particle is bent as it moves through a magnetic field because of the connection between electricity and magnetism. But that same connection means that a change in electric currents — which are made by the motion of charged particles — create changing magnetic fields. And if you have a changing magnetic field either around a wire or through a loop or coil of wire, you will generate electric currents!

    So while there may not be a danger to you, there is a huge danger to electronics, ranging from automobiles to transformers to — most frighteningly of all — the entire power grid! That’s the real danger of a solar storm: an event similar to the 1859 Carrington event could cause anywhere between an estimated $1-to-$2 trillion of property damage, mostly due to electrical fires and damage to our infrastructure.

    7
    Depiction of 1859 Carrington event.Politesseo

    8
    A number of NASA satellites throughout the solar system. Image credit: NASA.

    With the space weather satellites we had up just a few years ago, we would have about a half-day’s warning to shut down our power stations and voluntarily shut off the grid in the event of such a flare. With STEREO-A and STEREO-B operating simultaneously, however, we can know as soon as the flare occurs, giving us up to three days of lead time. These events cannot be predicted in advance, and neither can their interaction with the interplanetary-and-Earth’s magnetic field, so you must never listen to fear-mongers who tell you a catastrophic solar flare is imminent; we can only be prepared to react when one is detected.

    9
    The combination of NASA’s STEREO-A (ahead) and STEREO-B (behind), combined with the solar dynamics observatory (SDO) near Earth gives us a full view of the entire photosphere of the Sun at once. Image credit: NASA.

    Ideally, we’d be able to either upgrade the grid or to simply install a sufficient amount of electrical grounding, but practically, the first option is a long-term project that no one is working on, and the second one is continuously thwarted by thievery of copper wire. Power stations and substations simply do not maintain enough grounding due to this thievery, and there’s no known antidote to that, since if death-by-electrocution isn’t enough of a deterrent, what will be?

    There’s no need to be afraid of these things, but you do need to be prepared. If an ultra-massive, fast-moving coronal mass ejection ever heads directly towards Earth, you are literally taking your life into your hands if you do not shut down and unplug all of your electronic devices — and your power companies deliberately black out your neighborhood — until the storm passes. Long-distance wires, power stations and substations and the major components of the electrical grid itself will be at the greatest risk, as they will have huge direct currents (in systems designed only to carry AC) induced in them. The smartest move for those components, quite honestly, might be to sever the wires. That’s the only surefire way we have of personally safely dealing with things now.

    But you should also keep in mind that there’s only about a 1% chance we’ll get a large, powerful Earth-directed flare in any given year, and only about a 0.2% of getting an event like we did in 1859. So be aware, be informed and know how to deal with it if it happens, but don’t lose any sleep over it! Instead, your best bet is — when applicable — to go outside and enjoy the auroral show!

    This article is dedicated to Jake Morgan, whose fascination with solar storms led him to write his first book: Sunburned. Jake recently suffered a catastrophic accident and is undergoing significant time in the ICU; you can help support his GoFundMe here.

    See the full article here .

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    “Starts With A Bang! is a blog/video blog about cosmology, physics, astronomy, and anything else I find interesting enough to write about. I am a firm believer that the highest good in life is learning, and the greatest evil is willful ignorance. The goal of everything on this site is to help inform you about our world, how we came to be here, and to understand how it all works. As I write these pages for you, I hope to not only explain to you what we know, think, and believe, but how we know it, and why we draw the conclusions we do. It is my hope that you find this interesting, informative, and accessible,” says Ethan

     
  • richardmitnick 7:49 am on August 24, 2016 Permalink | Reply
    Tags: , , NASA STEREO   

    From Goddard: “NASA Establishes Contact With STEREO Mission” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    Aug. 22, 2016
    Karen C. Fox
    karen.c.fox@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    NASA/STEREO spacecraft
    NASA/STEREO spacecraft

    2
    On Aug. 21, 2016, NASA reestablished contact with the sun-watching STEREO-B spacecraft, after communications were lost in October 2014. STEREO-B is one of two spacecraft of the Solar Terrestrial Relations Observatory mission, which over the course of their lifetime have viewed the sun from vantage points such as the ones shown here, on the other side of the sun from Earth. This graphic shows the positions of the two STEREO spacecraft and their orbits in relation to Earth, Venus, Mercury and the sun. Credits: NASA

    On Aug. 21, 2016, contact was reestablished with one of NASA’s Solar Terrestrial Relations Observatories, known as the STEREO-B spacecraft, after communications were lost on Oct. 1, 2014. Over 22 months, the STEREO team has worked to attempt contact with the spacecraft. Most recently, they have attempted a monthly recovery operation using NASA’s Deep Space Network, or DSN, which tracks and communicates with missions throughout space.

    The DSN established a lock on the STEREO-B downlink carrier at 6:27 p.m. EDT. The downlink signal was monitored by the Mission Operations team over several hours to characterize the attitude of the spacecraft and then transmitter high voltage was powered down to save battery power. The STEREO Missions Operations team plans further recovery processes to assess observatory health, re-establish attitude control, and evaluate all subsystems and instruments.

    Communications with STEREO-B were lost during a test of the spacecraft’s command loss timer, a hard reset that is triggered after the spacecraft goes without communications from Earth for 72 hours. The STEREO team was testing this function in preparation for something known as solar conjunction, when STEREO-B’s line of sight to Earth – and therefore all communication – was blocked by the sun.

    STEREO-A continues to work normally.

    For more on STEREO: http://www.nasa.gov/stereo

    See the full article here.

    Please help promote STEM in your local schools.

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    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.

    NASA Goddard campus
    NASA/Goddard Campus
    NASA image

     
  • richardmitnick 1:58 pm on November 18, 2015 Permalink | Reply
    Tags: , , , , , NASA STEREO,   

    From AAS NOVA: “Eruptions from the Sun” 

    AASNOVA

    Amercan Astronomical Society

    18 November 2015
    Susanna Kohler

    1
    An image captured of the Sun by the Solar Dynamics Observatory’s Atmospheric Imaging Assembly, a few hours after a coronal mass ejection erupted off of the Sun’s northwest limb. [NASA/SDO/AIA]

    1
    Gif of a movie of the CME, taken by the Solar Dynamics Observatory’s Atmospheric Imaging Assembly at a wavelength of 304Å. The original movie can be found in [cited] the article.

    The Sun often exhibits outbursts, launching material from its surface in powerful releases of energy. Recent analysis of such an outburst — captured on video by several Sun-monitoring spacecraft — may help us understand the mechanisms that launch these eruptions.

    Many Outbursts

    Solar jets are elongated, transient structures that are thought to regularly release magnetic energy from the Sun, contributing to coronal heating and solar wind acceleration. Coronal mass ejections (CMEs), on the other hand, are enormous blob-like explosions, violently ejecting energy and mass from the Sun at incredible speeds.

    But could these two types of events actually be related? According to a team of scientists at the University of Science and Technology of China, they may well be. The team, led by Jiajia Liu, has analyzed observations of a coronal jet that they believe prompted the launch of a powerful CME.

    Observing an Explosion

    An army of spacecraft was on hand to witness the event on 15 Jan 2013 — including the Solar Dynamics Observatory (SDO), the Solar and Heliospheric Observatory (SOHO), and the Solar Terrestrial Relations Observatory (STEREO).

    NASA SDO
    NASA/SDO

    NASA SOHO
    NASA/SOHO

    NASA STEREO spacecraft
    NASA/STEREO

    The instruments on board these observatories captured the drama on the northern limb of the Sun as, at 19:32 UT, a coronal jet formed. Just eight minutes later, a powerful CME was released from the same active region.

    The fact that the jet and CME occurred in the same place at roughly the same time suggests they’re related. But did the initial motions of the CME blob trigger the jet? Or did the jet trigger the CME?

    Tying It All Together

    In a recently published study, Liu and collaborators analyzed the multi-wavelength observations of this event to find the heights and positions of the jet and CME. From this analysis, they determined that the coronal jet triggered the release of material to form the CME, which then erupted into space — with the jet at its core — at speeds of over 1000 km/s.

    Based on observed clues of the magnetic field configurations, the team has put together a theory for how this event unfolded. They believe that sudden magnetic reconnection in an active region accelerated plasma to form a large-scale coronal jet. This burst of energy also provided a push on a blob of gas, threaded with magnetic field lines, that lay above the jet. The blob then rose, and when the field lines broke, it was released as a CME with the jet at its core.

    Citation

    Jiajia Liu et al 2015 ApJ 813 115. doi:10.1088/0004-637X/813/2/115

    See the full article here .

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  • richardmitnick 5:18 am on October 15, 2015 Permalink | Reply
    Tags: , , , NASA STEREO,   

    From Goddard- “Comet Encke: A Solar Windsock Observed by NASA’s STEREO” 

    NASA Goddard Banner
    Goddard Space Flight Center

    Oct. 13, 2015
    Sarah Frazier
    NASA’s Goddard Space Flight Center

    1
    A visualization of the constant outflow of material from the sun, known as the solar wind. There is no consensus on what powers the solar wind’s acceleration, its extreme variability, or its remarkably high temperatures. Credits: ESA/NASA/SOHO

    Much like the flapping of a windsock displays the quick changes in wind’s speed and direction, called turbulence, comet tails can be used as probes of the solar wind – the constant flowing stream of material that leaves the sun in all directions. According to new studies of a comet tail observed by NASA’s Solar and Terrestrial Relations Observatory, or STEREO, the vacuum of interplanetary space is filled with turbulence and swirling vortices similar to gusts of wind on Earth. Such turbulence can help explain two of the wind’s most curious features: its variable nature and unexpectedly high temperatures. A paper on this work was published in The Astrophysical Journal on Oct. 13, 2015.

    NASA STEREO spacecraft
    STEREO

    “The solar wind at Earth is about 70 times hotter than one might expect from the temperature of the solar corona and how much it expands as it crosses the void,” said Craig DeForest, a solar physicist at the Southwest Research Institute in Boulder, Colorado, and lead author on the study. “The source of this extra heat has been a mystery of solar wind physics for several decades.”

    There is much that is conclusively known about the solar wind: It is made of a sea of electrically-charged electrons and ions and also carries the interplanetary magnetic field along for the ride, forging a magnetic connection between the sun and Earth and the other planets in the solar system. There is no consensus, however, on what powers the wind’s acceleration, especially when it is traveling at its fastest speeds. Complicating the search for such understanding are two of its most distinctive characteristics: The solar wind can be highly variable, meaning that measurements just short times or distances apart can yield quite different results. It is also very, very hot—remarkably so.

    The new study helped explain these characteristics using the heliospheric imager onboard STEREO. The scientists studied the movements of hundreds of dense chunks of glowing ionized gas within the ribbon of Comet Encke’s tail, which passed within STEREO’s field of view in 2007. Fluctuations in the solar wind are mirrored in what is seen in the tail, so by tracking these clumps, scientists were able to reconstruct the motion of the solar wind, catching an unprecedented look at the turbulence.

    Identifying this turbulence in the solar wind has the potential to solve the mystery of how the solar wind gets so hot. Based on the intensity of the turbulence researchers saw, they calculated that the energy available from turbulence is more than ten times what would be required to heat the solar wind to observed temperatures.

    What’s more, it also helps to solve the variability problem, which other theories have not yet done successfully.

    “This turbulent motion mixes up the solar wind, leading to the rapid variation that we see at Earth,” said DeForest.

    For years, scientists have taken direct measurements of the solar wind—known as in situ measurements, which are captured as the solar wind passes over one of the dozens of satellites carrying the appropriate instruments. Most of these satellites observe the sun from a vantage point similar to that of Earth. STEREO-A, however, orbits the sun in a slightly smaller and faster orbit than Earth, meaning it moves around the sun farther and farther from Earth over time. So, in addition to the images of Comet Encke as it streamed past in April 2007, STEREO-A also provides us with in situ solar wind measurements from a unique perspective.

    On the other hand, the solar wind is notoriously hard to study remotely—that is, with measurements from afar. Its particles flow at 250 miles per second, and they are so dispersed that interplanetary space at Earth’s orbit has about a thousand times fewer particles in one cubic inch of space than the best laboratory vacuum on Earth.

    This solar wind dominates the space environment within our solar system and travels well past Pluto, creating a huge bubble known as the heliosphere. Closer to home, the solar wind also interacts with Earth’s magnetic field, sometimes initiating changes in near-Earth space that can disrupt our space technology or cause auroras. So scientists needed to come up with a way to look at something that’s invisible—and that’s where Comet Encke came in.

    2
    Comet Encke’s ion tail can be seen stretching away from the sun towards the top of the image, captured by NASA’s MESSENGER spacecraft on Nov. 17, 2013, when the comet was about 33 million miles from the sun. The tail is created when the solar wind sweeps over the comet, capturing vaporized material and causing it to trail out behind the comet. The tail follows the lines of the magnetic field ingrained in the solar wind and reveals its motion. Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington/Southwest Research Institute

    All comets, if they get close enough to the sun, will form what’s called an ion tail. One of the most recognizable features of these hunks of ice and rock, the ion tail is created when the solar wind—made of hot, charged gas, called plasma—sweeps over the comet, capturing the material that has been vaporized into plasma by sunlight, causing it to trail out behind the comet. This tail follows the lines of the magnetic field embedded in the solar wind and reveals its motion.

    Comet Encke has some unusual characteristics that scientists were able to leverage to study the solar wind. Unlike most comets, Comet Encke has what is called a compact tail. Rather than feathering out loosely, creating a wide spray of ions, Comet Encke’s ion tail streams out in a tight, bright ribbon of glowing gas with compact features.

    3
    This video, captured by NASA’s STEREO mission, shows the motion of Comet Encke and its tail as it approached the sun in April 2007. Scientists studied the movements of hundreds of dense chunks of glowing ionized gas within the comet’s tail, finding evidence of turbulence that may explain both the solar wind’s variability and its unexpectedly high temperatures.
    Credits: NASA/STEREO

    “In situ measurements are limited because they don’t follow the turbulence along its path,” said William Matthaeus, a professor of physics and astronomy at the University of Delaware and co-author on the study. “Now, for the first time, we observed the turbulent motions along their complex paths and quantified the mixing. We actually see the turbulence.”

    Using the images from STEREO-A, scientists tracked 230 different features as they weaved through Comet Encke’s tail over the course of about 9.3 million miles of its journey around the sun. They then compared these motions to how they would expect solid objects to orbit around the sun, finding evidence that these gas clumps were being picked up by drag against the solar wind. They found that, though the gas clumps moved more or less randomly on smaller scales, they exhibited clear patterns on the scale of about 300,000 miles, indicating large-scale swirling eddies are mixing the solar wind—and possibly heating it as well.

    “Turbulent motion cascades down into motion on smaller and smaller scales until it hits the level of the fundamental gyrations of the particles about the magnetic field, where it becomes heat,” said Aaron Roberts, a heliophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This study estimates that there is enough energy contained in these swirling eddies to explain the extra heat several times over.”

    These observations of the solar wind provide a preview of what NASA plans to observe more directly with the Solar Probe Plus or SPP, mission in 2018.

    NASA SPP Solar Probe Plus

    SPP will travel to within nine solar radii of the sun, which is nine times the radius of the Sun, or about 3.9 million miles. Since it’s possible to remotely observe comets closer to the sun than any spacecraft can travel, studying them does provide unique information about the solar wind and our sun’s atmosphere.

    STEREO is the third mission in the NASA Heliophysics Division’s Solar Terrestrial Probes program, which is managed by NASA Goddard for NASA’s Science Mission Directorate, in Washington.

    Related:

    NASA’s STEREO project

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.

    NASA Goddard Campus
    NASA/Goddard Campus
    NASA

     
  • richardmitnick 2:53 pm on July 16, 2015 Permalink | Reply
    Tags: , , NASA STEREO,   

    From NASA: “STEREO-A Spacecraft Returns Data From the Far Side of the Sun” 

    NASA

    NASA

    Last Updated: July 16, 2015
    Editor: Sarah Loff

    1
    Image Credit: NASA/STEREO

    NASA STEREO spacecraft
    STEREO

    This image of the sun was taken on July 15, 2015, with the Extreme Ultraviolet Imager onboard NASA’s Solar TErrestrial RElations Observatory Ahead (STEREO-A) spacecraft, which collects images in several wavelengths of light that are invisible to the human eye. This image shows the sun in wavelengths of 171 angstroms, which are typically colorized in blue. STEREO-A has been on the far side of the sun since March 24, where it had to operate in safe mode, collecting and saving data from its radio instrument. The first images in over three months were received from STEREO-A on July 11.

    The three-month safe mode period was necessary because of the geometry between Earth, the sun, and STEREO-A. STEREO-A orbits the sun as Earth does, but in a slightly smaller and faster orbit. The orbit ensured that over the course of years, Earth and the spacecraft got out of sync, with STEREO-A ending up on the other side of the sun from Earth, where it could show us views of our star that we couldn’t see from home. Though the sun only physically blocked STEREO-A from Earth’s line of sight for a few days, STEREO-A was close enough to the sun—from our perspective — that from March 24 until July 8, the sun interfered with STEREO-A’s data transmission signal, making it impossible to interpret.

    As STEREO-A kept orbiting, it eventually made its way far enough from the sun to come out of this transmission dark zone. In late June, the STEREO-A team began receiving status updates from the spacecraft, confirming that it had made it through its long safe-mode journey unharmed.

    STEREO is the third mission in NASA’s Solar Terrestrial Probes program (STP). The mission, launched in October 2006, has provided a unique and revolutionary view of the sun-Earth system. The two nearly identical observatories – one ahead of Earth in its orbit, the other trailing behind – have traced the flow of energy and matter from the sun to Earth.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
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