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martes, 30 de agosto de 2016

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

http://www.esa.int/Our_Activities/Observing_the_Earth/The_Living_Planet_Programme/Campaigns/FLEX_takes_on_mutants

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.

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Plant power from above03 February 2015
ESA
Guillermo Gonzalo Sánchez Achutegui
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ESA : Rosetta captures comet outburst .- La Sonda Espacial Rosetta, capta imágenes de explosión de un cometa

http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_captures_comet_outburst
                               

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

ESA
Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com
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ESA : Llamaradas en la Estrella Polar .- Planck’s flame-filled view of the Polaris Flare

http://www.esa.int/esl/ESA_in_your_country/Spain/Llamaradas_en_la_Estrella_Polar
http://www.esa.int/spaceinimages/Images/2016/08/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

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  • 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

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Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
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