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  • richardmitnick 8:54 am on May 2, 2018 Permalink | Reply
    Tags: , , , , , , Solar Observation   

    From Chalmers University of Technology: “Flares in the universe can now be studied on earth” 

    Chalmers University of Technology

    02 May 2018

    Tünde Fülöp
    Professor, Department of Physics, Chalmers University of Technology
    +46 72 986 74 40
    tunde.fulop@chalmers.se

    Longqing Yi
    Postdoctoral researcher,Department of Physics,Chalmers University of Technology
    +46 31 772 68 82
    longqing@chalmers.se

    1
    Solar flares are caused by magnetic reconnection in space and can interfere with our communications satellites, affecting power grids, air traffic and telephony. Now, researchers at Chalmers University of Technology, Sweden, have found a new way to imitate and study these spectacular space plasma phenomena in a laboratory environment. Image: NASA/SDO/AIA/Goddard Space Flight Center

    NASA/SDO

    3
    Longqing Yi
    4
    Tünde Fülöp

    Solar flares, cosmic radiation, and the northern lights are well-known phenomena. But exactly how their enormous energy arises is not as well understood. Now, physicists at Chalmers University of Technology, Sweden, have discovered a new way to study these spectacular space plasma phenomena in a laboratory environment. The results have been published in the renowned journal Nature Communications.

    “Scientists have been trying to bring these space phenomena down to earth for a decade. With our new method we can enter a new era, and investigate what was previously impossible to study. It will tell us more about how these events occur,” says Longqing Yi, researcher at the Department of Physics at Chalmers.

    The research concerns so-called ‘magnetic reconnection’ – the process which gives rise to these phenomena. Magnetic reconnection causes sudden conversion of energy stored in the magnetic field into heat and kinetic energy. This happens when two plasmas with anti-parallel magnetic fields are pushed together, and the magnetic field lines converge and reconnect. This interaction leads to violently accelerated plasma particles that can sometimes be seen with the naked eye – for example, during the northern lights.

    Magnetic reconnection in space can also influence us on earth. The creation of solar flares can interfere with communications satellites, and thus affect power grids, air traffic and telephony.

    In order to imitate and study these spectacular space plasma phenomena in the laboratory, you need a high-power laser, to create magnetic fields around a million times stronger than those found on the surface of the sun. In the new scientific article, Longqing Yi, along with Professor Tünde Fülöp from the Department of Physics, proposed an experiment in which magnetic reconnection can be studied in a new, more precise way. Through the use of ‘grazing incidence’ of ultra-short laser pulses, the effect can be achieved without overheating the plasma. The process can thus be studied very cleanly, without the laser directly affecting the internal energy of the plasma. The proposed experiment would therefore allow us to seek answers to some of the most fundamental questions in astrophysics.

    “We hope that this can inspire many research groups to use our results. This is a great opportunity to look for knowledge that could be useful in a number of areas. For example, we need to better understand solar flares, which can interfere with important communication systems. We also need to be able to control the instabilities caused by magnetic reconnection in fusion devices,” says Tünde Fülöp.

    The study on which the new results are based was financed by the Knut and Alice Wallenberg foundation, through the framework of the project ‘Plasma-based Compact Ion Sources’, and the ERC project ‘Running away and radiating’.

    4
    Schematic of the proposed setup and relativistic jets generation. a A moderately high-intensity laser pulse (a0 = 5) propagates along the x-direction, and is splitted in half by a micro-sized plasma slab. The laser drives two energetic electron beams on both sides of the plasma surfaces, which generate 100 MG level opposing azimuthal magnetic fields in the middle. Ultrafast magnetic reconnection is observed as the electron beams approach the coronal region (the area within the blue box, where the plasma density decreases exponentially) at the end of the slab. The two insets below show the transverse magnetic fields (black arrows) and longitudinal electric current density (color) at the cross-section marked by the red rectangle (separated by 10λ0) at simulation times t = 24T0 and t = 34T0, respectively. b–e Generation and evolution of the relativistic jet resulting from MR at times 32T0, 35T0, 38T0, and 41T0, respectively. The rainbow color bar shows the transverse momentum P z of the jets formed by the background plasma electrons in b–e, and the blue-red color bar shows the energy of the electron bunch driven by the laser pulse in b, c.

    5
    Gyrotropy quantification at different times. Square root of quantified pressure tensor agyrotropy Q−−√ in the coronal plasma at simulation time t = 32T0(a), 33T0(b), and 34T0(c). The insets show the value of Q−−√ at the cross-section with longitudinal coordinate x = 26λ0, which is marked by the red rectangles in a–c.

    6
    Evolution of magnetic fields and magnetic tension force during the reconnection. a–c Static magnetic fields (frequency below 0.8ω0) and d–f z-component of magnetic tension force at simulation time t = 32T0 (a, d), 33T0 (b, e), and 34T0 (c, f). In a–c the transverse (B y , B z ) and longitudinal (B x ) components of magnetic field are presented by the black arrows and color, respectively. The bold white arrows in b show the inflow (horizontal) and outflow (vertical) electric currents that result from Hall reconnection. The black-dashed lines in d–f mark the cross-section where the corresponding magnetic fields (a–c) are shown.

    7
    Magnetic energy dissipation and the energization of non-thermal electrons. a Field dissipation (E x j x ) and electron density at t = 33T0 in the corona, the insets represent the top and side views of E x j x in the reconnection site (marked by the red box). b Time dependence of total energy increase in electrostatic fields, electrons in the corona, and protons (ΔE+), energy reduction of electromagnetic fields and other electrons (ΔE−), as well as the total energy reduction that includes magnetic field dissipation (ΔE− + ΔEm), inset shows the evolution of static magnetic energy Em and total kinetic energy of electron jets. c Coronal electron spectra from 30T0 to 36T0. d The temporal evolution of the kinetic energy (Ek) and the work done by each electric field component (W x , W y , and W z ) for one representative electron. The inset plane shows the phase-space trajectory (γ − 1 plotted vs. y) of the total 100 tracked electrons, where the blue-dashed line marks the boundary of plasma slab and the trajectory in red represents the case shown in d.

    Text:
    Mia Halleröd Palmgren,
    mia.hallerodpalmgren@chalmers.se

    Translation:
    Joshua Worth, joshua.worth@chalmers.se

    See the full article here .

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    Chalmers University of Technology (Swedish: Chalmers tekniska högskola, often shortened to Chalmers) is a Swedish university located in Gothenburg that focuses on research and education in technology, natural science, architecture, maritime and other management areas

    The University was founded in 1829 following a donation by William Chalmers, a director of the Swedish East India Company. He donated part of his fortune for the establishment of an “industrial school”. Chalmers was run as a private institution until 1937, when the institute became a state-owned university. In 1994, the school was incorporated as an aktiebolag under the control of the Swedish Government, the faculty and the Student Union. Chalmers is one of only three universities in Sweden which are named after a person, the other two being Karolinska Institutet and Linnaeus University.

     
  • richardmitnick 12:57 pm on October 14, 2017 Permalink | Reply
    Tags: , Hard X-rays, , , Nanoflares, , NASA Sounding Rocket Instrument Spots Signatures of Long-Sought Small Solar Flares, NASA UC Berkeley FOXSI sounding rocket, One of the consequences of nanoflares would be pockets of superheated plasma, , Solar Observation   

    From Goddard: “NASA Sounding Rocket Instrument Spots Signatures of Long-Sought Small Solar Flares” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Oct. 13, 2017
    Sarah Frazier
    sara.frazier@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    Like most solar sounding rockets, the second flight of the FOXSI instrument – short for Focusing Optics X-ray Solar Imager – lasted 15 minutes, with just six minutes of data collection. But in that short time, the cutting-edge instrument found the best evidence to date of a phenomenon scientists have been seeking for years: signatures of tiny solar flares that could help explain the mysterious extreme heating of the Sun’s outer atmosphere.

    FOXSI detected a type of light called hard X-rays – whose wavelengths are much shorter than the light humans can see – which is a signature of extremely hot solar material, around 18 million degrees Fahrenheit. These kinds of temperatures are generally produced in solar flares, powerful bursts of energy. But in this case, there was no observable solar flare, meaning the hot material was most likely produced by a series of solar flares so small that they were undetectable from Earth: nanoflares. The results were published Oct. 9, 2017, in Nature Astronomy.

    “The key to this result is the sensitivity in hard X-ray measurements,” said Shin-nosuke Ishikawa, a solar physicist at the Japan Aerospace Exploration Agency, or JAXA, and lead author on the study. “Past hard X-ray instruments could not detect quiet active regions, and combination of new technologies enables us to investigate quiet active regions by hard X-rays for the first time.”

    1
    The NASA-funded FOXSI instrument captured new evidence of small solar flares, called nanoflares, during its December 2014 flight on a suborbital sounding rocket. Nanoflares could help explain why the Sun’s atmosphere, the corona, is so much hotter than the surface. Here, FOXSI’s observations of hard X-rays are shown in blue, superimposed over a soft X-ray image of the Sun from JAXA and NASA’s Hinode solar-observing satellite.
    Credits: JAXA/NASA/

    JAXA/NASA HINODE spacecraft


    NASA UC Berkeley JAXA FOXSI sounding rocket

    These observations are a step toward understanding the coronal heating problem, which is how scientists refer to the extraordinarily – and unexpectedly – high temperatures in the Sun’s outer atmosphere, the corona. The corona is hundreds to thousands of times hotter than the Sun’s visible surface, the photosphere. Because the Sun produces heat at its core, this runs counter to what one would initially expect: normally the layer closest to a source of heat, the Sun’s surface, in this case, would have a higher temperature than the more distant atmosphere.

    “If you’ve got a stove and you take your hand farther away, you don’t expect to feel hotter than when you were close,” said Lindsay Glesener, project manager for FOXSI-2 at the University of Minnesota and an author on the study.

    The cause of these counterintuitively high temperatures is an outstanding question in solar physics. One possible solution to the coronal heating problem is the constant eruption of tiny solar flares in the solar atmosphere, so small that they can’t be directly detected. In aggregate, these nanoflares could produce enough heat to raise the temperature of the corona to the millions of degrees that we observe.

    One of the consequences of nanoflares would be pockets of superheated plasma. Plasma at these temperatures emits light in hard X-rays, which are notoriously difficult to detect. For instance, NASA’s RHESSI satellite – short for Reuven Ramaty High Energy Solar Spectroscopic Imager – launched in 2002, uses an indirect technique to measure hard X-rays, limiting how precisely we can pinpoint the location of superheated plasma. But with the cutting-edge optics available now, FOXSI was able to use a technique called direct focusing that can keep track of where the hard X-rays originate on the Sun.

    “It’s really a completely transformative way of making this type of measurement,” said Glesener. “Even just on a sounding rocket experiment looking at the Sun for about six minutes, we had much better sensitivity than a spacecraft with indirect imaging.”

    FOXSI’s measurements – along with additional X-ray data from the JAXA and NASA Hinode solar observatory – allow the team to say with certainty that the hard X-rays came from a specific region on the Sun that did not have any detectable larger solar flares, leaving nanoflares as the only likely instigator.

    “This is a proof of existence for these kinds of events,” said Steve Christe, the project scientist for FOXSI at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and an author on the study. “There’s basically no other way for these X-rays to be produced, except by plasma at around 10 million degrees Celsius [18 million degrees Fahrenheit]. This points to these small energy releases happening all the time, and if they exist, they should be contributing to coronal heating.”

    There are still questions to be answered, like: How much heat do nanoflares actually release into the corona?

    “This particular observation doesn’t tell us exactly how much it contributes to coronal heating,” said Christe. “To fully solve the coronal heating problem, they would need to be happening everywhere, even outside of the region observed here.”

    Hoping to build up a more complete picture of nanoflares and their contribution to coronal heating, Glesener is leading a team to launch a third iteration of the FOXSI instrument on a sounding rocket in summer 2018. This version of FOXSI will use new hardware to eliminate much of the background noise that the instrument sees, allowing for even more precise measurements.

    A team led by Christe was also selected to undertake a concept study developing the FOXSI instrument for a possible spaceflight as part of the NASA Small Explorers program.

    FOXSI is a collaboration between the United States and JAXA. The second iteration of the FOXSI sounding rocket launched from the White Sands Missile Range in New Mexico on Dec. 11, 2014. FOXSI is supported through NASA’s Sounding Rocket Program at the Goddard Space Flight Center’s Wallops Flight Facility in Virginia. NASA’s Heliophysics Division manages the sounding rocket program.

    Related:

    JAXA press release on these findings (Japanese)
    NASA-funded FOXSI to Observe X-rays from Sun
    https://www.nasa.gov/mission_pages/sounding-rockets/index.html

    See the full article here.

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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

     
  • richardmitnick 1:03 pm on January 17, 2017 Permalink | Reply
    Tags: , , , Solar Observation   

    From ALMA: “ALMA Starts Observing the Sun” This is a Blast 

    ALMA Array

    ALMA

    17 January 2017
    Nicolás Lira T.
    Press Coordinator
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 24 67 65 19
    Cell: +56 9 94 45 77 26
    Email: nicolas.lira@alma.cl

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
    Tel: +1 434 296 0314
    Cell: +1 202 236 6324
    E-mail: cblue@nrao.edu

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

    Cell: +49 151 1537 3591
    Email: rhook@eso.org

    Masaaki Hiramatsu

    Education and Public Outreach Officer, NAOJ Chile
    Observatory
Tokyo, Japan

    Tel: +81 422 34 3630

    E-mail: hiramatsu.masaaki@nao.ac.jp

    1
    This image of the entire Sun was taken at a wavelength of 617.3 nm. Light at this wavelength originates from the visible solar surface, the photosphere. A cooler, darker sunspot is clearly visible in the disk, and — as a visual comparison — a depiction from ALMA at a wavelength of 1.25 millimeters is shown. Credit: ALMA (ESO/NAOJ/NRAO); B. Saxton (NRAO/AUI/NSF) | Full-disc solar image: Filtergram taken in Fe I 617.3 nm spectral line with the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO). Credit: NASA

    NASA/SDO
    NASA/SDO

    New images from the Atacama Large Millimeter/submillimeter Array (ALMA) reveal stunning details of our Sun, including the dark, contorted center of an evolving sunspot nearly twice as large as the diameter of the Earth. These images are part of the testing and verification campaign to make ALMA’s solar observing capabilities available to the international astronomical community.

    Though designed principally to observe remarkably faint objects throughout the Universe — such as distant galaxies and planet-forming disks around young stars – ALMA is also capable of studying objects in our own Solar System, including planets, comets, and now our own Sun.

    2
    This ALMA image of an enormous sunspot was taken on 18 December 2015 with the Band 6 receiver at a wavelength of 1.25 millimeters. Sunspots are transient features that occur in regions where the Sun’s magnetic field is extremely concentrated and powerful. They are lower in temperature than their surrounding regions, which is why they appear relatively dark in visible light. The ALMA image is essentially a map of temperature differences in a layer of the Sun’s atmosphere known as the chromosphere, which lies just above the visible surface of the Sun (the photosphere). The chromosphere is considerably hotter than the photosphere. Understanding the heating and dynamics of the chromosphere are key areas of research that will be addressed by ALMA. Observations at shorter wavelengths probe deeper into the solar chromosphere than longer wavelengths. Hence, Band 6 observations map a layer of the chromosphere that is closer to the visible surface of the Sun than Band 3 observations. Credit: ALMA (ESO/NAOJ/NRAO)

    During a 30-month period beginning in 2014, an international team of astronomers harnessed ALMA’s single-antenna and array capabilities to detect and image the millimeter-wavelength light emitted by the Sun’s chromosphere — the region that lies just above the photosphere, the visible surface of the Sun.

    4
    ALMA image of an enormous sunspot taken on 18 December 2015 with the Band 3 receiver at a wavelength of 3 millimeters. Sunspots are transient features that occur in regions where the Sun’s magnetic field is extremely concentrated and powerful. They are lower in temperature than their surrounding regions, which is why they appear relatively dark in visible light. The ALMA images are essentially maps of temperature differences in a layer of the Sun’s atmosphere known as the chromosphere, which lies just above the visible surface of the Sun (the photosphere). The chromosphere is considerably hotter than the photosphere. Understanding the heating and dynamics of the chromosphere are key areas of research that will be addressed by ALMA. Observations at shorter wavelengths probe deeper into the solar chromosphere than longer wavelengths. Hence, Band 6 observations map a layer of the chromosphere that is closer to the visible surface of the Sun than Band 3 observations. Credit: ALMA (ESO/NAOJ/NRAO)

    These new images demonstrate ALMA’s ability to study solar activity at longer wavelengths than observed with typical solar telescopes on Earth, and are an important expansion of the range of observations that can be used to probe the physics of our nearest star.

    5
    This full map of the Sun at a wavelength of 1.25 mm was taken with a single ALMA antenna using a so-called “fast-scanning” technique. The accuracy and speed of observing with a single ALMA antenna makes it possible to produce a low-resolution map of the entire solar disk in just a few minutes. Such images can be used in their own right for scientific purposes, showing the distribution of temperatures in the chromosphere, the region of the solar atmosphere that lies just above the visible surface of the Sun. Credit: ALMA (ESO/NAOJ/NRAO)

    “We’re accustomed to seeing how our Sun appears in visible light, but that can only tell us so much about the dynamic surface and energetic atmosphere of our nearest star,” said Tim Bastian, an astronomer with the National Radio Astronomy Observatory in Charlottesville, Virginia in the USA. “To fully understand the Sun, we need to study it across the entire electromagnetic spectrum, including the millimeter and submillimeter portion that ALMA can observe.”

    Since our Sun is many billions of times brighter than the faint objects ALMA typically observes, the solar commissioning team had to developed special procedures to enable ALMA to safely image the Sun without damaging its sensitive electronics.

    The result of this work is a series of images that demonstrates ALMA’s unique vision and ability to study our Sun on multiple scales.

    The ALMA Solar Development Team includes Shin’ichiro Asayama, East Asia ALMA Support Center, Tokyo, Japan; Miroslav Barta, Astronomical Institute of the Czech Academy of Sciences, Ondrejov, Czech Republic; Tim Bastian, National Radio Astronomy Observatory, USA; Roman Brajsa, Hvar Observatory, Faculty of Geodesy, University of Zagreb, Croatia; Bin Chen, New Jersey Institute of Technology, USA; Bart De Pontieu, LMSAL, USA; Gregory Fleishman, New Jersey Institute of Technology, USA; Dale Gary, New Jersey Institute of Technology, USA; Antonio Hales, Joint ALMA Observatory, Chile; Akihiko Hirota, Joint ALMA Observatory, Chile; Hugh Hudson, School of Physics and Astronomy, University of Glasgow, UK; Richard Hills, Cavendish Laboratory, Cambridge, UK; Kazumasa Iwai, National Institute of Information and Communications Technology, Japan; Sujin Kim, Korea Astronomy and Space Science Institute, Daejeon, Republic of Korea; Neil Philips, Joint ALMA Observatory, Chile; Tsuyoshi Sawada, Joint ALMA Observatory, Chile; Masumi Shimojo, NAOJ, Tokyo, Japan; Giorgio Siringo, Joint ALMA Observatory, Chile; Ivica Skokic, Astronomical Institute of the Czech Academy of Sciences, Ondrejov, Czech Republic; Sven Wedemeyer, Institute of Theoretical Astrophysics, University of Oslo, Norway; Stephen White, AFRL, USA; Pavel Yagoubov, ESO, Garching, Germany; and Yihua Yan, NAO, Chinese Academy of Sciences, Beijing, China.

    See the full article here .

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    The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

    ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

    NRAO Small

    ESO 50

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  • richardmitnick 2:25 pm on November 14, 2016 Permalink | Reply
    Tags: , , , Solar Observation   

    From DKIST via Maui Economic Development Board: “Most Advanced Solar Telescope on Earth” 

    DKIST
    Daniel K. Inouye Solar Telescope

    dkist-new
    Daniel K. Inouye Solar Telescope,DKIST under construction by the National Solar Observatory atop the Haleakala volcano on the Pacific island of Maui, Hawaii, USA

    Maui Economic Development Board

    November 9, 2016

    The Daniel K. Inouye Solar Telescope (DKIST) is on schedule for full operations in June 2020. Situated at 10,000 feet of elevation atop Haleakala, the DKIST will be the most advanced ground-based solar observatory in the world. With more than 20 institutions collaborating internationally, it is about to revolutionize the world of solar astronomy. “We are pointing a four-meter (13 foot) telescope at the Sun for the very first time, which will challenge the science community to take their understanding to a whole new level,” said Dr. Thomas Rimmele, DKIST Project Director, National Solar Observatory (NSO). “When combined with a special adaptive optics system, the DKIST’s primary mirror will produce high-speed measurements to examine the Sun’s surface in stunning detail!”

    The site on Haleakala was selected, out of a global search, for its clear daytime atmospheric seeing conditions. Once operational, the DKIST will allow astronomers to measure the magnetic fields that drive space weather events such as solar flares and coronal mass ejections. “Understanding the behavior of the Sun’s magnetic fields is vital,” Rimmele explained. “Monitoring space weather is essential as our society increasingly relies on electronics technology that is susceptible to damage from these large space events. DKIST will help us better deal with threats of outages.”

    DKIST Project Manager Dr. Joseph McMullin of NSO provided the latest updates. “The external building has been completed, with the integration of major telescope systems underway. This includes the telescope mount assembly and the rotating instrument laboratory,” McMullin noted. “The optical systems, and the primary mirror, the most critical element of the telescope, have met their challenging, state-of-the-art specifications and are undergoing testing.”

    DKIST’s open data policy will provide the general public access to unique data resources compiled by the best engineers and scientists in the world. “In fact, the DKIST will bring more jobs and educational outreach opportunities to Maui,” Rimmele added. “The scientific impact from the DKIST, for all of humanity, is immense. The entire global community will be looking to Maui for this extraordinary science!”

    See the full article here .

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    The Daniel K. Inouye Solar Telescope (DKIST, formerly the Advanced Technology Solar Telescope, ATST) represents a collaboration of 22 institutions, reflecting a broad segment of the solar physics community. The construction phase of the project, to build the next generation ground-based solar telescope, is underway now.

     
  • richardmitnick 3:04 pm on October 25, 2016 Permalink | Reply
    Tags: , , , Solar Observation, 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.

    2
    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 .

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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
    NASA/Goddard Campus
    NASA image

     
  • richardmitnick 10:45 am on September 12, 2016 Permalink | Reply
    Tags: , , Solar Observation   

    From ESA: “Proba-3” 

    ESA Space For Europe Banner

    European Space Agency

    12 September 2016
    No writer credit found

    1
    Proba-3 satellites form artificial eclipse

    By converging in orbit, a pair of small satellites will open a new view on the source of the largest structure in the Solar System: the Sun’s ghostly atmosphere, extending millions of kilometres out into space.

    The two satellites together are called Proba-3, set for launch in late 2019. Through precise formation flying, one will cast a shadow across the second to open up an unimpeded view of the inner area of the ‘corona’, which is a million times fainter than the blindingly brilliant solar disc.

    “When I first heard of the idea I said ‘Wow! That’s just what we need’,” said Andrei Zhukov of the Royal Observatory of Belgium, serving as Principal Investigator for Proba-3’s solar instrument.

    “The best way to observe the corona from the ground is during a solar eclipse, although we still have to cope with stray light – we cannot correct for the influence of Earth’s atmosphere.

    2
    Solar eclipses provide an excellent opportunity to observe the atmosphere of the solar corona which is normally hidden from view. The corona shows quite a simple pattern at solar minimum (left), becoming highly complex at solar maximum (right). Wendy Carlos & Fred Espenak

    “The next best method is by using ‘coronagraphs’ to create an articifical eclipse, either on ground telescopes or inside Sun-watching satellites such as SOHO and Stereo.

    ESA/SOHO
    ESA/SOHO

    NASA/STEREO spacecraft
    NASA/STEREO spacecraft

    “The problem is that stray light bending around the edge of the occulting disc limits our view of the most important inner portion of the corona. SOHO’s coronagraph, for instance, can observe no closer in than 1.1 Sun-diameters. Others can see closer, but with strong stray light making detailed observation impossible.

    “With Proba-3 we aim to see extremely close to the solar surface in visible light, by flying the occulter and coronagraph on separate satellites some 150 m apart.

    “This should give us a ringside seat on the most interesting segment of the corona, where a lot of interesting physics is going on, where the solar wind is born and ‘coronal mass ejections’ originate – gigantic solar eruptions with the potential to affect our terrestrial infrastructure.”

    While the Sun’s surface is a comparatively cool 6000ºC, the corona averages a sizzling million degrees. The mystery is how energy travels from the cool Sun to the hot corona, in apparent defiance of the laws of thermodynamics.

    “By mapping the fine structure of the inner corona for a prolonged time – we are targeting around six hours – our hope is that we gain insight into the kind of energy flows that are taking place,” notes Dr Zhukov.

    3
    Proba-3’s pair of satellites will be in a highly elliptical orbit around Earth, performing formation flying manoeuvres as well as scientific studies of the solar corona. The occulter satellite will have solar panels on its Sun-facing side. ESA – P. Carril, 2013

    “Our standard observing mode will be once per minute, but we could speed that up to a few seconds within a selected field of view, for instance when tracing the rapid evolution of a mass ejection.

    “The ultimate goal is to be able to solve the physics of space weather, in order to forecast coronal mass ejections, which are known to have dramatic effects on terrestrial electricity grids and other infrastructure.”

    Proba-3 is first and foremost a technology demonstration, exploring the potential of precise formation flying in orbit, but achieving meaningful scientific results will also help to prove its approach works.


    Proba-3: Dancing with the stars

    See the full article here .

    Please help promote STEM in your local schools.

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    Stem Education Coalition

    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

    ESA50 Logo large

     
  • richardmitnick 12:30 pm on August 29, 2016 Permalink | Reply
    Tags: , , Solar Observation, , SwRI Solar Instrument Pointing Platform (SSIPP)   

    From SwRI: “SwRI to demonstrate low-cost miniature solar observatory” 

    SwRI bloc

    Southwest Research Institute

    August 29, 2016
    Deb Schmid
    (210) 522-2254

    1
    The SwRI Solar Instrument Pointing Platform (SSIPP) is a miniature, low-cost solar observatory designed to conduct solar research from the near-space environment. SwRI hang tested the SSIPP payload, which will be demonstrated in August carried aloft by a stratospheric balloon.
    Image Courtesy of Southwest Research Institute

    Southwest Research Institute will flight test a miniature solar observatory on a six-hour high-altitude balloon mission scheduled for the end of August. The SwRI Solar Instrument Pointing Platform (SSIPP) is a complete, high-precision solar observatory about the size of a mini fridge and weighing 160 pounds.

    “This novel, low-cost prototype was developed for less than $1 million, which is one-tenth the cost of other comparable balloon-borne observatories,” said Principal Investigator Dr. Craig DeForest, a principal scientist in SwRI’s Space Science and Engineering Division. “Funded by NASA’s Game-Changing Technologies program, SSIPP is a reusable, optical table-based platform. This novel approach breaks down barriers to science by allowing low-cost solar research.”

    SSIPP collects solar data using infrared, ultraviolet, or visible light instruments on an optical table, similar to those used in ground-based observatories but from a near-space environment. This arcsecond-class observatory provides optical precision equivalent to imaging a dime from a mile away. Originally conceived to fly aboard a commercial suborbital rocket, SSIPP has now been adapted for balloon flight. Collecting data from the edge of space — around 20 miles above the Earth’s surface — avoids image distortions caused by looking through the atmosphere.

    “SSIPP could support the development of a range of new instruments for the near-space environment at relatively low cost,” DeForest said. “Using a standard optical table platform increases flexibility, allowing scientists to try new things and develop new technologies without designing a custom observatory.”

    During the demonstration, scientists will spend two hours commissioning the observatory and searching for visible signatures of “high-frequency” solar soundwaves, which are actually some eight octaves below the deepest audible notes. By contrast, the most studied sound waves in the Sun (the solar “P-modes” used to probe the solar interior) are five octaves deeper still.

    The surface of the Sun is covered with granular convection cells analogous to a pot of water at a rolling boil. Continuously, every 5 minutes, a million of these cells erupt, creating sound waves at a range of frequencies. SSIPP will image the solar atmosphere to understand their heat and noise properties. The comparatively high frequency of the “solar ultrasound” waves makes them undetectable by ground-based observatories.

    “The transfer of heat to the surface of our star is a violent and tremendously loud process,” DeForest said. “Soundwaves heat the solar atmosphere to extremely high temperatures, but it’s a poorly understood process. Existing measurements of the solar infrasound cannot account for all the energy required.”

    SSIPP will launch aboard a World View stratospheric balloon, funded by NASA’s Flight Opportunities Program under the Space Technology Mission Directorate. The program is managed by NASA’s Armstrong Flight Research Center in Edwards, California.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    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.

     
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