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martes, 30 de agosto de 2016

ESA : FLEX takes on mutants .- Fluorescence Explorer – FLEX adquiere mutantes


FLEX takes on mutants

Mutant strip
25 August 2016
Because a plant isn’t green doesn’t mean it can’t photosynthesise as well as its more usual counterpart, but when measured by satellites, these non-green varieties skew results on plant health. FLEX is different. Experiments using ‘mutants’ show that colour won’t be an obstacle in this new mission’s task of mapping plant health from space.
Planned to be launch around 2022, ESA’s Fluorescence Explorer – FLEX – will use a novel technique to track the health of the world’s vegetation.
This technique involves detecting and measuring the faint glow that plants give off as they use sunlight to convert carbon dioxide into energy-rich carbohydrates – photosynthesis.
FLEX will improve our understanding of the way carbon moves between plants and the atmosphere and how photosynthesis affects the carbon and water cycles.
Moreover, accurate information about the health and stress of the planet’s vegetation is important as the growing global population places increasing demands on the production of food and animal feed.
As part of the development of this new satellite mission, scientists in Italy and Germany have been studying different crops to understand the relationship between the light reflected by different plants and their carbon uptake.
Mutants on the right
The latest field campaigns focus on the natural mutant soybean MinnGold, which only has 20% of the chlorophyll of ‘normal’ green plants.
Such chlorophyll deficiency changes the properties of the leaves, which are a yellowy colour. As such, these mutant soybean leaves reflect much more sunlight than their green cousins, leaving the plant with less energy to photosynthesise.
Although they have less energy, these mutants are surprisingly more efficient at fixing carbon dioxide from the air.
Traditional satellite techniques rely on measuring aspects of reflected light to estimate plant productivity and cannot account for unusual coloured plants.
FLEX concept

Radoslaw Juszczak from the Poznań University of Life Sciences in Poland explained, “Chlorophyll-deficient plants have similar photosynthetic rates as their green counterparts.
“But, indeed, they pose a challenge for conventional reflectance-based remote sensing methods to estimate photosynthesis.”
Since FLEX takes a different approach by measuring the fluorescence that plants give off as they photosynthesise, plant colour will no longer be an obstacle.
Nevertheless, field experiments are needed to confirm that this is the case.
Setting up mutant experiment
The latest campaign uses the HyPlant sensor – an airborne demonstrator developed for FLEX by FZ-Juelich in Germany. It comprises two ‘imaging spectrometers’, which are essentially cameras that see the reflected and the emitted light from the surface at different wavelengths.
Dirk Schuettemeyer, ESA’s campaign coordinator, said, “For the first time, we can test these new ideas related to plant physiology that can be detected by airborne instruments, paving the way for the FLEX instrument under development.
“In the first instance, HyPlant can clearly see the long strip of soybean mutants next to the green fields. The next step is to quantify fluorescence for the different fields to prove the theory of similar photosynthetic rates for mutant and original soybean crops.”
The campaign teams are now busy processing and analysing the data collected. The first results will be presented at a workshop in January.

Related articles

Plant power from above03 February 2015
Guillermo Gonzalo Sánchez Achutegui
Inscríbete en el Foro del blog y participa : A Vuelo De Un Quinde - El Foro!

ESA : Rosetta captures comet outburst .- La Sonda Espacial Rosetta, capta imágenes de explosión de un cometa


Comet outburst

Rosetta captures comet outburst

25 August 2016
In unprecedented observations made earlier this year, Rosetta unexpectedly captured a dramatic comet outburst that may have been triggered by a landslide.
Nine of Rosetta’s instruments, including its cameras, dust collectors, and gas and plasma analysers, were monitoring the comet from about 35 km in a coordinated planned sequence when the outburst happened on 19 February.
“Over the last year, Rosetta has shown that although activity can be prolonged, when it comes to outbursts, the timing is highly unpredictable, so catching an event like this was pure luck,” says Matt Taylor, ESA’s Rosetta project scientist.
“By happy coincidence, we were pointing the majority of instruments at the comet at this time, and having these simultaneous measurements provides us with the most complete set of data on an outburst ever collected.”

Evolution of a comet outburst

The data were sent to Earth only a few days after the outburst, but subsequent analysis has allowed a clear chain of events to be reconstructed, as described in a paper led by Eberhard Grün of the Max-Planck-Institute for Nuclear Physics, Heidelberg, accepted for publication in Monthly Notices of the Royal Astronomical Society.

Which instruments detected the outburst?

A strong brightening of the comet’s dusty coma was seen by the OSIRIS wide-angle camera at 09:40 GMT, developing in a region of the comet that was initially in shadow.
Over the next two hours, Rosetta recorded outburst signatures that exceeded background levels in some instruments by factors of up to a hundred. For example, between about 10:00–11:00 GMT, ALICE saw the ultraviolet brightness of the sunlight reflected by the nucleus and the emitted dust increase by a factor of six, while ROSINA and RPC detected a significant increase in gas and plasma, respectively, around the spacecraft, by a factor of 1.5–2.5.
In addition, MIRO recorded a 30ºC rise in temperature of the surrounding gas.
Shortly after, Rosetta was blasted by dust: GIADA recorded a maximum hit count at around 11:15 GMT. Almost 200 particles were detected in the following three hours, compared with a typical rate of 3–10 collected on other days in the same month.
At the same time, OSIRIS narrow-angle camera images began registering dust grains emitted during the blast. Between 11:10 GMT and 11:40 GMT, a transition occurred from grains that were distant or slow enough to appear as points in the images, to those either close or fast enough to be captured as trails during the exposures.
In addition, the startrackers, which are used to navigate and help control Rosetta’s attitude, measured an increase in light scattered from dust particles as a result of the outburst.
The startrackers are mounted at 90º to the side of the spacecraft that hosts the majority of science instruments, so they offered a unique insight into the 3D structure and evolution of the outburst. 
Astronomers on Earth also noted an increase in coma density in the days after the outburst.

Location of the outburst
By examining all of the available data, scientists believe they have identified the source of the outburst.
“From Rosetta’s observations, we believe the outburst originated from a steep slope on the comet’s large lobe, in the Atum region,” says Eberhard.
The fact that the outburst started when this area just emerged from shadow suggests that thermal stresses in the surface material may have triggered a landslide that exposed fresh water ice to direct solar illumination. The ice then immediately turned to gas, dragging surrounding dust with it to produce the debris cloud seen by OSIRIS.
“Combining the evidence from the OSIRIS images with the long duration of the GIADA dust impact phase leads us to believe that the dust cone was very broad,” says Eberhard.
“As a result, we think the outburst must have been triggered by a landslide at the surface, rather than a more focused jet bringing fresh material up from within the interior, for example.”
“We’ll continue to analyse the data not only to dig into the details of this particular event, but also to see if it can help us better understand the many other outbursts witnessed over the course of the mission,” adds Matt.
“It’s great to see the instrument teams working together on the important question of how cometary outbursts are triggered.”
Notes for Editors
The 19 Feb. 2016 outburst of comet 67P/CG: A Rosetta multi-instrument study,” by E. Grün et al is published in the Monthly Notices of the Royal Astronomical Society. doi: 10.1093/mnras/stw2088
For further information, please contact:
Eberhard Grün
Max-Planck-Institute for Nuclear Physics, Heidelberg, Germany
Email: eberhard.gruen@mpi-hd.mpg.de
Matt Taylor
ESA Rosetta project scientist
Email: matthew.taylor@esa.int
Markus Bauer 

ESA Science and Robotic Exploration Communication Officer

Tel: +31 71 565 6799

Mob: +31 61 594 3 954

Email: markus.bauer@esa.int

country > Spain

Emisión en el Cometa

Rosetta captura una potente emisión

26 agosto 2016 Durante una serie de observaciones sin precedentes a principios de este año, Rosetta capturó inesperadamente una espectacular emisión en 67P/Churyumov-Gerasimenko, quizá provocada por un deslizamiento de tierra.
Cuando se produjo, el 19 de febrero, nueve de los instrumentos de Rosetta, incluidas sus cámaras, colectores de polvo y analizadores de gas y plasma, vigilaban el cometa a unos 35 km de distancia, en una secuencia programada y coordinada.
Como comenta Matt Taylor, científico del proyecto Rosetta de la ESA: “A lo largo del pasado año, Rosetta ha demostrado que, aunque la actividad que provocan puede prolongarse, estas emisiones son altamente impredecibles, por lo que capturar un evento así fue cuestión de suerte”.
“Dio la casualidad de que, en ese momento, la mayoría de los instrumentos apuntaban al cometa y, ahora, todas esas mediciones simultáneas nos ofrecen los datos más completos jamás recogidos sobre una emisión”. 
Evolución de la emisión
Pocos días tras producirse la emisión, los datos recopilados se enviaron a la Tierra, donde su posterior análisis ha permitido reconstruir claramente la cadena de eventos, que se describen en un artículo dirigido por Eberhard Grün, del Instituto Max-Planck de Física Nuclear en Heidelberg, Alemania, y publicado en la revista Monthly Notices of the Royal Astronomical Society
¿Qué instrumentos detectaron la emisión?
A las 09:40 GMT, la cámara de gran angular OSIRIS captó en la coma un fuerte brillo que se desarrollaba desde una región del cometa inicialmente en la sombra.
A lo largo de las dos horas siguientes, Rosetta registró datos de la emisión que multiplicaban hasta por cien los niveles base de algunos instrumentos. Por ejemplo, entre las 10:00 y las 11:00 GMT, ALICE detectó el brillo ultravioleta de la luz solar reflejada en el núcleo y un fuerte aumento del polvo emitido, que se sextuplicó. Al mismo tiempo, ROSINA y RPC captaron un aumento significativo de gas y plasma (multiplicándose su densidad por un factor de 1,5–2,5) alrededor del satélite.
Por su parte, MIRO registró un aumento de 30 ºC en la temperatura del gas colindante y, poco después, Rosetta fue azotada por una nube de polvo: el analizador GIADA registró un máximo hacia las 11:15 GMT y, durante las tres horas siguientes, se detectaron casi 200 partículas, cuando en otros días del mismo mes lo normal era detectar de 3 a 10.
Al mismo tiempo, el teleobjetivo de la cámara OSIRIS comenzó a fotografiar los granos de polvo emitidos durante la emisión. Entre las 11:10 GMT y las 11:40 GMT, se produjo una transición en las imágenes, que pasaron de mostrar granos distantes o lo bastante lentos como para aparecer en forma puntos a mostrar estas partículas como estelas debido a su cercanía o velocidad.
Además, los sensores de estrellas utilizados para la navegación y el control de la actitud de Rosetta midieron un aumento en la luz emitida por las partículas de polvo como consecuencia de la emisión.
Gracias a su situación, montados a 90º en el lateral del satélite que aloja la mayoría de los instrumentos científicos, los sensores pudieron ofrecer datos únicos sobre la estructura tridimensional y la evolución de la emisión.
Los astrónomos en la Tierra también detectaron un incremento en la densidad de la coma durante los días siguientes a la emisión.
Lugar de la emisión
Una vez examinados los datos disponibles, los científicos creen haber identificado la fuente de la emisión.
“A partir de las observaciones de Rosetta, creemos que se originó en una pendiente pronunciada en el lóbulo mayor del cometa, en la región de Atum”, explica Eberhard.
El hecho de que la emisión comenzara cuando esta área acababa de salir de la sombra sugiere que la tensión térmica en el material superficial podría haber provocado un deslizamiento de tierra que dejó hielo de agua expuesto a la radiación solar. El hielo se habría evaporado rápidamente, arrastrando polvo consigo hasta producir la nube de residuos detectada por OSIRIS.
“La combinación de las imágenes recogidas por las cámaras de OSIRIS con los datos recopilados por GIADA durante la fase de impacto del polvo nos lleva a pensar que el diámetro del cono de polvo fue de gran tamaño —admite Eberhard—. Por eso creemos que la emisión pudo deberse a un deslizamiento de tierra en la superficie, y no a una ráfaga concreta que expulsara materia desde el interior, por ejemplo”.
Matt añade: “Seguiremos analizando los datos para profundizar en los datos de este evento en concreto, y también para ver si nos ayuda a comprender la multitud de emisiones que hemos detectado a lo largo de nuestra misión”.
“Es fantástico ver cómo los distintos equipos responsables de los instrumentos colaboran para estudiar cómo se originan estas emisiones en los cometas”.

Nota para los editores
El artículo “The 19 Feb. 2016 outburst of comet 67P/CG: A Rosetta multi-instrument study,” de E. Grün et al., está publicado en la revista Monthly Notices of the Royal Astronomical Society. doi: 10.1093/mnras/stw2088
Para más información:
Eberhard Grün
Max-Planck-Institute for Nuclear Physics, Heidelberg, Germany
Correo electrónico: eberhard.gruen@mpi-hd.mpg.de
Matt Taylor
ESA Rosetta project scientist
Correo electrónico: matthew.taylor@esa.int
Markus Bauer 

ESA Science and Robotic Exploration Communication Officer

Teléfono: +31 71 565 6799

Móvil: +31 61 594 3 954

Correo electrónico: markus.bauer@esa.int

Guillermo Gonzalo Sánchez Achutegui
Inscríbete en el Foro del blog y participa : A Vuelo De Un Quinde - El Foro!

ESA : Llamaradas en la Estrella Polar .- Planck’s flame-filled view of the Polaris Flare


Llamaradas en la Estrella Polar

22 agosto 2016
Esta imagen del satélite Planck de la ESA parece fruto de la imaginación: una figura emerge de las llamas a modo de espectro rojo y se desplaza hacia la izquierda de la fotografía en un remolino de cálidos colores.
Esta potente ilusión es, en realidad, la nube molecular conocida como “Polaris Flare”. Esta formación, de unos 10 años luz de diámetro, está compuesta por una maraña de filamentos de polvo alrededor de Polaris, en la constelación de la Osa Menor, a unos 500 años luz de distancia.
La nube se encuentra cerca del Polo Norte Celeste, un punto en el firmamento alineado con el eje de rotación de la Tierra. Esta línea imaginaria, que atraviesa los hemisferios norte y sur, apunta a los dos polos celestes. Para encontrar el Polo Celeste Norte, el observador solo tiene que localizar la Estrella Polar, o Polaris, que es la estrella más brillante de la constelación de la Osa Menor.
Algunos de los secretos de “Polaris Flare” fueron desvelados hace algunos años por el observatorio Herschel de la ESA. Gracias a una combinación de las observaciones de Herschel y a una simulación por ordenador, los científicos han llegado a la conclusión de que los filamentos de la red de Polaris podrían haberse formado mediante ondas de choque atravesando lentamente una densa nube interestelar, es decir, una acumulación de gas y polvo cósmico frío situada entre las estrellas de nuestra Galaxia.
Estas ondas de choque, similares a los estampidos sónicos en la Tierra, habrían sido generadas por la explosión de estrellas cercanas que, con su muerte, perturbaron el espacio a su alrededor, provocando una serie de turbulencias. Estas ondas hicieron que el gas y el polvo se elevase a su paso, formando los serpenteantes filamentos que se aprecian en la imagen.
Esta imagen no es una vista a color real ni una reproducción simulada de la red de filamentos, sino que comprende observaciones realizadas por el satélite Planck entre 2009 y 2013. Planck peinó y cartografió la totalidad del firmamento, incluyendo el plano de la Vía Láctea, en busca de signos de luz antigua (lo que se conoce como la radiación cósmica de fondo) y emisiones de polvo cósmico. Y fue precisamente una emisión de polvo lo que permitió a Planck crear este mapa único del firmamento: un mapa magnético.
Las líneas en relieve muestran la dirección aproximada del campo magnético de nuestra galaxia en la región de Polaris. La imagen fue creada utilizando la emisión observada de polvo cósmico polarizado (forzado en una dirección determinada). Los granos de polvo en la Vía Láctea y sus alrededores se ven afectados por el campo magnético de la Galaxia, entrelazándose con él y alineándose preferencialmente en el espacio. Este efecto se ha trasladado a la emisión de polvo, que también muestra una orientación preferencial, orientación detectada aquí por Planck.
Las emisiones de polvo cósmico se calculan a partir de una serie de observaciones realizadas por Planck a 353, 545 y 857 GHz, mientras que la dirección del campo magnético se deriva de los datos de polarización tomados por Planck a 353 GHz. Esta fotografía abarca un área de 30 x 30º en el firmamento y los colores representan la intensidad de la emisión de polvo.

Planck’s flame-filled view of the Polaris Flare

Planck’s flame-filled view of the Polaris Flare


  • Title Planck’s flame-filled view of the Polaris Flare
  • Released 22/08/2016 11:52 am
  • Copyright ESA and the Planck Collaboration
  • Description
    This image from ESA’s Planck satellite appears to show something quite ethereal and fantastical: a sprite-like figure emerging from scorching flames and walking towards the left of the frame, its silhouette a blaze of warm-hued colours.
    This fiery illusion is actually a celestial feature named the Polaris Flare. This name is somewhat misleading; despite its moniker, the Polaris Flare is not a flare but a 10 light-year-wide bundle of dusty filaments in the constellation of Ursa Minor (The Little Bear), some 500 light-years away.
    The Polaris Flare is located near the North Celestial Pole, a perceived point in the sky aligned with Earth’s spin axis. Extended into the skies of the northern and southern hemispheres, this imaginary line points to the two celestial poles. To find the North Celestial Pole, an observer need only locate the nearby Polaris (otherwise known as the North Star or Pole Star), the brightest star in the constellation of Ursa Minor.
    Some of the secrets of the Polaris Flare were uncovered when it was observed by ESA’s Herschel some years ago. Using a combination of such Herschel observations and a computer simulation, scientists think that the Polaris Flare filaments could have been formed as a result of slow shockwaves pushing their way through a dense interstellar cloud, an accumulation of cold cosmic dust and gas sitting between the stars of our Galaxy.
    These shockwaves, reminiscent of the sonic booms formed by fast sound waves here on Earth, would have been themselves triggered by nearby exploding stars that disrupted their surroundings as they died, triggering cloud-wide waves of turbulence
    These shockwaves, reminiscent of the sonic booms formed by fast sound waves here on Earth, were themselves triggered by nearby exploding stars that disrupted their surroundings as they died, triggering cloud-wide waves of turbulence. These waves swept up the gas and dust in their path, sculpting the material into the snaking filaments we see.
    This image is not a true-colour view, nor is it an artistic impression of the Flare, rather it comprises observations from Planck, which operated between 2009 and 2013. Planck scanned and mapped the entire sky, including the plane of the Milky Way, looking for signs of ancient light (known as the cosmic microwave background) and cosmic dust emission. This dust emission allowed Planck to create this unique map of the sky – a magnetic map.
    The relief lines laced across this image show the average direction of our Galaxy’s magnetic field in the region containing the Polaris Flare. This was created using the observed emission from cosmic dust, which was polarised (constrained to one direction). Dust grains in and around the Milky Way are affected by and interlaced with the Galaxy’s magnetic field, causing them to align preferentially in space. This carries through to the dust’s emission, which also displays a preferential orientation that Planck could detect.
    The emission from dust is computed from a combination of Planck observations at 353, 545 and 857 GHz, whereas the direction of the magnetic field is based on Planck polarisation data at 353 GHz. This frame has an area of 30 x 30º on the sky, and the colours represent the intensity of dust emission.
  • Id 364216


Guillermo Gonzalo Sánchez Achutegui
Inscríbete en el Foro del blog y participa : A Vuelo De Un Quinde - El Foro!

ESA : Proba-3: seeing through shadow to view Sun’s corona .- Proba-3: ver a través de la sombra para ver la corona del Sol



Proba-3 formation flying satellites
22 August 2016
Every 18 months or so, scientists and sensation-seekers gather at set points on Earth’s surface, to await awe-inspiring solar eclipses. The Moon briefly blocks the Sun, revealing its mysterious outer atmosphere, the corona. Though what if researchers could induce such eclipses at will?
That’s the scientific vision behind ESA’s double-satellite Proba-3, the world’s first precision formation-flying mission, planned for launch in 2019.
An ‘occulter’ satellite will fly 150 m ahead of a second ‘coronagraph’ satellite, casting a precise shadow to reveal the ghostly tendrils of the solar corona, down to 1.2 solar radii, for hours on end.
“We have two scientific instruments aboard,” explains Damien Galano, Proba-3 Payload Manager. “The primary payload is ASPIICS, a coronagraph to observe the corona in visible light while the DARA radiometer on the occulter measures the total solar irradiance coming from the Sun – a scientific parameter about which there is still some uncertainty. 
Proba-3 revealing corona
“The corona is a million times fainter than the Sun itself, so the light from the solar disk needs to be blocked in order to see it. The coronagraph idea was conceived by astronomer Bernard Lyot in the 1930s – and since then has been developed and has been incorporated into both Earth-based and space telescopes.
“But because of the wave nature of light, even within the cone of shadow cast by the occulter, some light still spills around the occulter edges, a phenomenon called ‘diffraction’.
“To minimise this unwanted light, the coronagraph can be positioned closer to the occulter – and therefore deeper into the shadow cone. However the deeper it is, the more the solar corona will also be occulted by the occulter. 
Coronagraph on single satellite
“Hence the advantage of a larger occulter and the maximum possible distance between the occulter and the coronagraph. Obviously a 150-m-long satellite is not a practical proposition, but our formation flying approach should provide us with equivalent performance.
“Furthermore, the ASPIICS coronagraph itself contains a smaller, secondary occulter disk, to cut down on diffracted light still further.
Coronagraph across two satellites

“Precision is all – the aperture of the ASPIICS instrument measures 50 mm in diameter, and for corona observation performance it should remain as much as possible in the centre of the shadow, which is about 70 mm across at 150 m.
"So we’ll need to achieve millimetre-scale positioning control between the two spacecraft, effectively forming a single giant instrument across space.”
ASPIICS (Association of Spacecraft for Polarimetry and Imaging of the Corona of the Sun) is being developed for ESA by a consortium led by Centre Spatial de Liège in Belgium, made up of 15 companies and institutes from five ESA Member States.
Diffraction of light
“Many of these companies are new to ESA, and they’ve proved to be very motivated and eager to show their capabilities,” remarks Damien. “We’ve produced various prototypes of instrument elements, and our first complete ‘structural and thermal model’ should be complete in the autumn, ahead of our end-of-year Critical Design Review.
“We’re also looking into various optical aspects, such as the best occulter edge shape to minimise diffraction.”
There’s a lot of broader interest in this external occulter approach – especially for the imaging of Earth-like exoplanets, which would require the blocking out of their parent stars.
“It’s a similar challenge, the main difference being that the star in question is a point source of light rather than the extended source that our Sun is.
“So it could be that formation-flown external occulters become versatile scientific tools, opening many new vistas in astronomy.”
Proba-3: Dancing with the stars

Guillermo Gonzalo Sánchez Achutegui
Inscríbete en el Foro del blog y participa : A Vuelo De Un Quinde - El Foro!

NSF : Discovery .- Biodiversity in salt marshes builds climate resilience .- La biodiversidad en las marismas construye la resistencia al clima

Los ecosistemas costeros de todo el mundo están sintiendo el calor del cambio climático. En el sureste de EE.UU., marismas han sufrido enormes hierba mortandad como consecuencia de la intensa sequía, lo que puede afectar todo, desde la pesca a la calidad del agua.

Relationship between mussels and marsh grass protects species, prevents grass die-off
Ribbed mussels support salt marsh grasses during a 2016 drought at Sapelo Island, Georgia.

Ribbed mussels support salt marsh grasses during a 2016 drought at Sapelo Island, Georgia.
Credit and Larger Version

August 19, 2016
Coastal ecosystems worldwide are feeling the heat of climate change. In the Southeastern U.S., salt marshes have endured massive grass die-offs as a result of intense drought, which can affect everything from fisheries to water quality.
Now, new research shows that a mutualistic relationship -- where two organisms benefit from each other's activities -- between ribbed mussels and salt marsh grasses may play a critical role in helping salt marshes bounce back from extreme climate events such as drought.
The results, reported this week in the journal Nature Communications, found that mussels piled up in mounds around salt grass stems helped to protect the grasses by improving water storage around their roots and reducing soil salinity. With the mussels' help, marshes can recover from drought in less than a decade. Without their help, it can take more than a century.
"This is a very good example of how the diversity of life in a salt marsh promotes resilience to climate and environmental change," said David Garrison, program director in the National Science Foundation (NSF) Division of Ocean Sciences, which co-funded the research with NSF's Division of Environmental Biology.
Marsh grass, mussels and mutual dependence
"It's a story of mutual benefit between marsh grass and mussels," said Christine Angelini, a scientist at the University of Florida and lead author of the paper.
The mussels, she said, "protect then accelerate the healing of drought-stricken marshes."
Saving the marshes has environmental and economic benefits.
"Marsh die-off and loss can affect land value, fisheries and water quality," Angelini said. "Even if just a little bit of vegetation survives, it makes a huge difference in how quickly the marsh comes back."
Angelini and the paper's co-authors became interested in the topic when three severe droughts in the Southeast over the past 17 years caused a major die-off of cordgrass, the region's dominant, marsh-structuring plant.
Using Google Earth, the team selected nine sites that contained relatively large marsh areas likely to experience drought-associated grass die-offs. The sites, which were chosen at the end of a severe, two-year drought in June 2012, spanned 150 miles of coastline from southern Georgia to central South Carolina.
The marine biologists found that wherever there were clusters of mussels embedded in the mud around the base of the grass stems, the grass survived. In fact, grass growing in mussel clusters had a 64 percent probability of surviving, compared to a one percent probability in areas without mussels.
The researchers suspected that mussels, by paving the marsh surface with their ribbed shells, attracted burrowing crabs that excavate underground water storage compartments.
Backyard study site
One marsh study site was in the backyard of Dale Aren.
Sixteen years ago, Aren and her family bought property on Coburg Creek in Charleston, South Carolina. The scenery, which included a large marsh area, played a major role in their decision to buy the land.
Aren noticed, however, that the marsh behind her home was dying.
"We were worried," she said. "The Spartina [grass] is beautiful but the increasing area of mudflats did not look healthy."
Eventually Aren found a paper that described the problem. Brian Silliman, the University of Florida biologist who wrote the paper, is also a co-author of the current Nature Communications paper.
On the Aren property, researchers noticed that, in spite of the grass die-off, little patches of grass remained in the mudflats, mostly where there were mussels. They found that once the drought subsided, these dispersed grass patches expanded rapidly, healing the mudflats from the inside out.
Three years later, the mudflats on Aren's property have largely recovered and reverted back to healthy marsh.
Mussel transplants?
According to Angelini, the next step is figuring out whether transplanting mussels into drought-vulnerable marshes could offer a low-cost solution to improve marshes' resilience.
The scientists are also testing whether other at-risk ecosystems -- such as seagrass meadows and coral reefs -- may be similarly protected by mutualistic relationships between keystone species.
Other institutions involved in the research include Swansea University in the United Kingdom; the University of Groningen and Radboud University in the Netherlands; the Royal Netherlands Institute for Sea Research; and Duke University.
Cheryl Dybas, NSF (703) 292-7734
Steve Orlando, University of Florida (352) 846-3903

Investigators Brian Silliman
Christine Angelini
Related Institutions/Organizations Duke University
University of Florida
Related Awards #1546638 EAGER: Secondary foundation species as drivers of ecosystem resilience
#1445834 CAREER: Small Grazers, Multiple Stressors and the Proliferation of Fungal Disease in Marine Plant Ecosystems
Total Grants $491,722
Related WebsitesGrass-planting change boosts coastal wetland restoration success: https://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=136663
Dead stalks of salt marsh grasses in a Sapelo Island marsh; the grasses died in a 2011-2012 drought.
Dead stalks of salt marsh grasses in a Sapelo Island marsh; the grasses died in a 2011-2012 drought.
Credit and Larger Version
Ribbed mussels help maintain salt marsh grasses during a 2012 drought in Charleston, South Carolina.
Ribbed mussels help maintain salt marsh grasses during a 2012 drought in Charleston, South Carolina.
Credit and Larger Version
A mound of ribbed mussels is embedded in the mud around healthy salt marsh grass stems.
A mound of ribbed mussels is embedded in the mud around healthy salt marsh grass stems.
Credit and Larger Version
Mussels pave the surface around salt marsh grass stems in a Georgia marsh.
Mussels pave the surface around salt marsh grass stems in a Georgia marsh.
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Marsh grasses killed by soil salinity stress in a Sapelo Island salt marsh in July 2016.
Marsh grasses killed by soil salinity stress in a Sapelo Island salt marsh in July 2016.
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The National Science Foundation (NSF)
Guillermo Gonzalo Sánchez Achutegui
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ESA : The longest call .- La llamada más larga hasta ahora en el espacio..........desde el planeta Saturno hasta La Tierra...

El 10 de agosto de 2016, la estación de la ESA de seguimiento en New Norcia, con una antena   35 m de diámetro,  y 630 toneladas de peso,  enfocando al  espacio profundo en Australia Occidental recibe las señales transmitidas por el orbitador Cassini de la NASA; desde el planeta  Saturno, a través de 1,44 millones de kilómetros de espacio.


  • Title The longest call
  • Released 18/08/2016 10:23 am
  • Copyright ESA/D. O'Donnell
  • Description
    On 10 August 2016, ESA’s tracking station at New Norcia, Western Australia, hosting a 35 m-diameter, 630-tonne deep-space antenna, received signals transmitted by NASA’s Cassini orbiter at Saturn, through 1.44 billion km of space.
    “This was the farthest-ever reception for an ESA station, and the radio signals – travelling at the speed of light – took 80 minutes to cover this vast distance,” says Daniel Firre, responsible for supporting Cassini radio science at ESOC, ESA’s operations centre in Darmstadt, Germany.
    The signal reception was part of a series of tests to prepare several ESA stations to support Cassini’s radio science investigations, planned to begin later in 2016.
    This image shows New Norcia station as seen in 2014 by Dylan O’Donnell, an amateur photographer based in Byron Bay, Australia (the blob of light apparently hovering above the antenna is a light artefact, ‘lens flare’).
    More information
    New Norcia station
    Estrack ground station network
  • Id 364134



Guillermo Gonzalo Sánchez Achutegui
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ESA : Most distant catch for ESA station .- La mayor captación muy distante para la estación de la ESA

In 2016, NASA's Cassini mission will begin its final 'Grand Finale' and ESA’s superbly sensitive deep-space tracking stations will be called in to help gather crucial radio science data.
Cassini during Grand Finale
18 August 2016
An ESA tracking station has acquired signals from the international Cassini spacecraft orbiting Saturn, across more than 1.4 billion km of space.
Following a seven-year journey to Saturn, the NASA/ESA/ASI Cassini orbiter delivered Europe’s Huygens probe to the surface of Saturn’s mysterious moon Titan in January 2005, just a few months after becoming the first spacecraft to enter orbit around the giant gas planet.
Since then, Cassini and Huygens have returned a wealth of information on the Saturnian system to the global scientific community, helping us understand the massive planet, its multiple moons and its hauntingly beautiful system of rings.
Starting later this year, the mission will begin its final phase (see Cassini's Grand Finale) and ESA’s superbly sensitive deep-space tracking stations will be called in to help gather crucial radio science data.

The longest call

In an initial test on 10 August, ESA’s tracking station at New Norcia, Western Australia, hosting a 35 m-diameter, 630-tonne deep-space antenna, received signals transmitted by Cassini through 1.44 billion km of space.
ESA's New Norcia station (DSA-1) is designed to communicate with deep-space missions, typically at ranges in excess of 2 million km
New Norcia station
“This was the farthest-ever reception for an ESA station, and the radio signals – travelling at the speed of light – took 80 minutes to cover this vast distance,” says Daniel Firre, responsible for supporting Cassini radio science at ESOC, ESA’s operations centre in Darmstadt, Germany.
“We had to upgrade some software at ESOC, as we discovered that one file used for pointing the antenna did not have enough digits to encode the full distance to Cassini, but the test worked and demonstrated we can catch Cassini’s transmissions.”

Listening across the void

Some types of radio science observations use a ground station to detect signals transmitted from a spacecraft that have reflected off a planet or moon’s surface, or passed through the various layers of its atmosphere – or, in the case of Saturn, its rings.
Effects on the signals provide valuable information on the composition, state and structure of whatever they have passed through.
ESA's Estrack tracking station control room at ESOC, the European Space Operations Centre, Darmstadt
Tracking stations control room at ESOC
Numerous missions, including ESA’s Venus Express and Mars Express, have used this technique in the past. All three of ESA’s deep-space tracking stations (New Norcia in Australia, Cebreros in Spain and Malargüe in Argentina) were specifically designed to enable a radio science capability.
The Cassini mission has performed radio science observations many times during its time at Saturn. Previously, the mission relied solely on the antennas of NASA's Deep Space Network for these observations.
Now, the addition of ESA tracking capability will help provide the continuous radio contact needed during Cassini radio science activities. The data received by ESA will be delivered to NASA for subsequent scientific analysis.

Radio science during the Grand Finale

Starting in December and running into July 2017, Cassini will conduct a daring series of orbits in which the spacecraft will repeatedly climb high above Saturn’s poles, initially passing just outside its narrow F ring, and then later diving between the uppermost atmosphere and the innermost ring.
In 2016, NASA's Cassini mission will begin its final 'Grand Finale' and ESA’s superbly sensitive deep-space tracking stations will be called in to help gather crucial radio science data.
Grand Finale orbits
When Cassini plunges past Saturn, an ESA station will listen, recording radio signals that will be relayed to NASA.
These data will provide detailed maps of Saturn’s gravity, revealing the planet’s inner composition and possibly helping solve the mystery of just how fast the interior is rotating. They will also help scientists study the rings.
Until December, a half-dozen more test passes using ESA’s New Norcia and Malargüe stations to receive Cassini signals are planned, after which the two will be used during some two-dozen Grand Finale orbits.

Inter-agency cooperation is a key element

The support is particularly challenging, as listening passes can last up to 30 hours, during which reception will be handed over multiple times between the two ESA stations and NASA’s Canberra deep-space communication complex in Australia; NASA’s Madrid complex will also take part.
“We need uninterrupted signal reception to optimise the Cassini radio science data, so the ESA and NASA stations really have to work in close coordination for recording and handover,” says Manfred Lugert, responsible for ESA’s Estrack ground station network.
Due to geometry, the two ESA stations – located in the southern hemisphere – are ideally able to support Cassini radio science. Northern/southern hemispheric coverage was one factor taken into account when ESA built its station in Argentina in 2012.
“We are really pleased that we can work closely with our NASA colleagues and contribute to Cassini’s incredibly valuable radio science goals,” says Manfred, adding: “It’s an impressive display of what two agencies working together can achieve.”

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Guillermo Gonzalo Sánchez Achutegui
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NSF : Discovery.- Turn your eyes to the skies for the latest explorers.- Girar los ojos a los cielos en busca de los últimos exploradores


6 ways NSF-supported research is improving unmanned aerial systems for scientific and societal benefit
Low-level flight test

A low-level flight test by Michael Shafer and his team at Northern Arizona University.
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August 18, 2016
From strengthening wildlife conservation efforts to improving disaster response, researchers are finding new ways to use small, unmanned aerial vehicles (UAVs) -- also known as drones or unmanned aerial systems (UAS) -- to gather data, improve communication, and explore environments where humans and larger aircraft dare not go.
These advances are due, in part, to improvements in UAV technology, as well as clearer ground rules that govern the many uses of unmanned aircraft. Increased federal funding, including a recent $35 million commitment from the National Science Foundation (NSF), will advance the basic research needed to design UAVs that can save lives, improve safety, and enable more effective science.
"Designing and developing highly-capable UAS platforms requires basic research in the theoretical principles of UAS, including sensing, perception, control and communications," says Lynne Parker, NSF director of the division of information and intelligent systems. "Once these agile and robust UAS systems are developed, they can be extended to operate in a variety of challenging domains, such as serving as vital tools for scientific exploration."
Since 2010, NSF has funded dozens of UAV research projects related to computing, engineering, earth science and biology, and supported entrepreneurs through its Small Business Innovation Research program.
The examples below demonstrate the potential for researchers to advance their scientific knowledge and provide benefits to society through the use of unmanned aircraft.
Wildlife conservation
With their ability to travel at altitudes and in environments where manned aircraft cannot, UAVs can study species in difficult-to-reach locations, and to help researchers address a number of important questions about ecosystems.
Michael Shafer, an assistant professor of mechanical engineering at Northern Arizona University, is working on an NSF-funded project to better track wildlife -- particularly small animals such as bats and birds -- in non-intrusive manner. By developing low-cost, UAV-mounted radio telemetry systems that can receive radio signals from tagged wildlife, and by making the pre-engineered systems available to wildlife researchers via open source publishing, he hopes to significantly reduce the barriers to tracking animals in the wild.
Shafer's lightweight modules leverage the flight capabilities of UAVs to better detect signals from wildlife transmitters. This involves developing signal-processing algorithms to assist in detecting and localizing very high frequency radio tags, and assembling a radio system capable of providing the required sensitivity. It also involves designing a system compact enough to fit on a UAV, along with special vehicles for field researchers and the radio-sensing modules they carry.
In addition to the technical development effort, Shafer and his team plan to work with the Upward Bound program at Northern Arizona University to guide first-generation, low-income high school students from the Four Corners region -- Arizona, Utah, Colorado and New Mexico -- toward successful college careers.
Increasing the accuracy of weather forecasts
UAVs are particularly well-suited for gathering data in the lower atmosphere (1,000-4,000 meters), where many weather phenomena begin and where manned aircraft are too dangerous or expensive to fly. Radar cannot always track conditions at this level and weather balloons have too short of a duration at these altitudes.
Through the $6 million, four-year Collaboration Leading Operational UAS Development for Meteorology and Atmospheric Physics (CLOUD-MAP) project, Oklahoma State University, the University of Oklahoma, the University of Kentucky, and the University of Nebraska will work together to develop the capabilities of meteorologists and atmospheric scientists to use unmanned aircraft as an everyday research tool.
The CLOUD-MAP project recently completed its first flight campaign, which resulted in nearly 250 unmanned flights of 12 separate UAV platforms over a three-day period -- one of the largest scientific unmanned aircraft operations ever. The effort, which brought together more than 65 researchers and students, collected important meteorological, climatological and operational data that will increase the accuracy of weather forecasts, ultimately saving lives and property.
Enhancing communications in a disaster
NSF CAREER awardee Yan Wan from the University of North Texas is developing aerial networking systems that use directional antennas on UAVs to deliver on-demand communication to first responders in emergency response situations.
Typical wireless communications have a range of only 100 meters, or just over the length of a football field. Wan and her colleagues, however, developed technology that extends the Wi-Fi reach of drones to 8 kilometers, or about 5 miles.
Wan and her team have worked with emergency agencies across Texas to test their system's ability to quickly establish emergency communications in disaster drills and exercises. In May 2015, working with researchers from Worcester Polytechnic Institute and the Austin Fire Department, she demonstrated how UAVs can establish aerial communication in a search-and-rescue operation, providing emergency responders with the aerial views they need to direct robots to find victims quickly and transmitting video streams of survivors to control centers. For this, and other activities, she and her colleagues won the Dallas-Fort Worth Metroplex's 2015 Tech Titan Award.
UAVs in hurricane and nuclear disasters
Robin Murphy, the director of the Center for Robot-Assisted Search and Rescue (CRASAR) at Texas A&M University, has deployed UAVs to some of the worst natural and man-made disasters in recent memory.
In the wake of Hurricane Katrina, Murphy directed UAVs to explore buildings along the Gulf Coast -- the first time an unmanned aircraft was used for emergency structural inspections. During the nuclear meltdown at the Fukushima Daiichi plant in Japan, she was part of a team that flew UAVs to determine radiation levels and inspect damage at the reactors. And in the days following the 2015 floods in Texas, Murphy led a team that deployed UAVs to inspect the storm-ravaged area.
Murphy determined that one 20-minute drone flight would generate roughly 800 photographs, each of which takes a minute to inspect. This led her to conclude that data analysis tools, deployed alongside unmanned aircraft, are necessary to make UAV technology useful in time-sensitive situations.
Working with collaborators and students, Murphy has developed software that uses computer vision and machine learning to improve UAV flight paths, as well as anomaly detection techniques to better locate survivors with UAVs.
Combining the capabilities of UAVs with tools that allow them to work in a targeted way is the secret to developing effective search-and-rescue UAVs, Murphy believes.
Sea ice mapping
Last year, scientists aboard the Nathaniel B. Palmer research vessel carried out two separate UAV trials as part of a research cruise in the Southern Ocean. The flights evaluated the aerial mapping of sea ice to determine the distribution of floating sea ice. [Watch a video of the flights.]
Researchers on the trip were exploring the vulnerability of Antarctic ice to melting due to the presence of relatively warm ocean water below it. Melting ice would drive glaciers into the sea faster and raise sea levels worldwide. This data will inform for future integrated observation programs.
In remote and dangerous locations such as Antarctica, UAVs can help to gather critical information without endangering human pilots, which is why the NSF-managed U.S. Antarctic Program is developing a policy on the safe and environmentally sound use of UAVs in Antarctic research.
Safer, cheaper infrastructure monitoring
As U.S. infrastructure ages, its operators need more efficient and affordable techniques to monitor and assess bridges, railroads, power lines, dams and other large systems. UAVs enable innovative approaches for monitoring the health and stability of structures from above and below.
Ivan Bartoli of Drexel University leads a project that focuses not just on UAVs, but on what those unmanned aircraft look at. Using novel manufacturing processes, his team designs special surface coatings -- like paint -- that enable UAVs to rapidly collect multi-spectral imaging data. Advanced algorithms then analyze that data to find structural deformations, allowing engineers to quickly identify damage to critical components of monitored structures.
Scientists and engineers are already moving many of these technologies out of the lab and into the marketplace. Hung La of the University of Nevada, Reno is building on NSF-funded research to create low-cost UAVs and robotic systems that can efficiently inspect steel and concrete bridges.
La is part of an NSF Innovation Corps Team that has completed more than 160 customer interviews, helping him focus on customer uses as the research team finalizes the drone and robotic platform and thinks about the long-term commercialization of the technology. The product has been tested and deployed in the field, and La is working with his university to patent the technology.
These and other new ways of thinking about infrastructure are leading to a safer, more stable future.
-- Aaron Dubrow, National Science Foundation (703) 292-4489 adubrow@nsf.gov

Investigators Hung La
Yan Wan
Bob McKee
Jingang Yi
Shengli Fu
Jamey Jacob
Adam Houston
Ivan Bartoli
Robin Murphy
Frank Nitsche
Paul Flikkema
Suzanne Smith
Carol Chambers
Michael Shafer
Nenad Gucunski
Phillip Chilson
Antonios Kontsos
Matthew McCarthy
Related Institutions/Organizations Drexel University
Columbia University
Oklahoma State University
University of North Texas
Northern Arizona University
Rutgers University New Brunswick
Texas A&M Engineering Experiment Station
Related Programs Supporting Fundamental Research in Unmanned Aerial Systems
Total Grants $4,892,685
University of Nevada researchers are developing an efficient, low-cost tool for inspecting bridges.
University of Nevada researchers are developing an efficient, low-cost tool for inspecting bridges.
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CO2-sensing UAV
Oklahoma State University research engineer Taylor Mitchell launches a CO2-sensing UAV.
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Drones and Robots to Save Lives: Smart Emergency Response System (SERS) Demonstration
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UAVs can transmit real-time monitoring videos to a control center, enhancing emergency response.
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Northern Arizona University UAV Demonstration
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A member of Michael Shafer's research team testing a UAV equipped with a radio telemetry system.
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The National Science Foundation (NSF)
Guillermo Gonzalo Sánchez Achutegui
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