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At the link below is an article on the recent discovery of the protective roll
of solar wind within the Heliosphere against high energy cosmic radiation,
such as gamma rays. shielding life on this planet (and other planets) from such radiation.
I would like to discuss here the implications of this discovery for optical and radio astronomy.
specifically the probability of attenuation and filtering of stellar radiowave and visible light
emissions from stars outside the Heliosphere.
Main Article from the website of
The Insitute for Physics and Astronomy
Ruhr University Bochum, Germany
URL: http://www.pm.rub.de/pm2009/msg00331.htm
for those of you who cannot read german
I have translated the text into english here :
The protective cocoon of the solar system
NASA probe reveals unexpected structures
Ruhr University Bochum Scientist Presents Two Papers
The solar wind envelops our solar system like a cocoon:
This continuous plasma stream emanating from the sun, protects us from the interstellar medium,
primarily from cosmic radiation at the boundry of the Heliosphere.
the NASA probe IBEX (Interstellar Boundary Explorer) for the first time
delivered measurements of energetic hydrogen atoms from this region, and also a surprise:
They suggest completely unexpected structures in the flow of these particles.
All previous calculations have excluded the magnetic field of the interstellar medium
so no one had expected such a strong influence.
Dr. Horst Fichtner (Institute for Theoretical Physics - Ruhr University Bochum)
presents these observations, and improved models of the cocoon,
to international colleagues, in two scientific articles.
Electron exchange at the edge of the heliosphere
Last October the IBEX probe was launched into Earth orbit with new detectors
pointed away from Earth into space,
recording as many high-energy hydrogen atoms from all directions per unit of time.
Gradually, as IBEX scanned the entire sky and delivered the first full-sky map of the particle flux,
conclusions about the physical processes at the outer edges of our solar system revealed:
On the edge of the heliosphere - plasma cocoons resulting from solar wind in the interstellar medium,
the solar wind consists mostly of fast moving protons,
while the interstellar medium to a large extent consists of slow moving hydrogen atoms.
When they come very close, there is a certain probability of electron exchange,
with electrons moving from slow hydrogen atoms to fast moving protons.
"When the particles exchange roles," explains Dr. Fichtner,
"the fast proton converting to fast hydrogen atom and vice versa.
The result of this exchange, we can. Measure '.
Calculation without the interstellar magnetic field
The result of such measurements obtained from IBEX, however, surprised the scientists.
It responded only partially to the previously calculated theoretical models
that were based on the assumption that the flux of energetic atoms is essentially determined by the solar wind.
It was instead a "diagonal" of the sky map with edge bands of strong intensity,
ie relatively large number of exchange processes between slow and fast neutral,
charged particles.
"Now we know why," said Horst Fichtner. "This band fits the magnetic field in the interstellar medium.
This size was previously neglected in the model. "
New scenarios
The second contribution of Science, the researchers are now designing scenarios to explain the discovered facts.
"We suspect that the dynamic role of the magnetic field
leads to a compression of the heliosphere at the boundry, " said Fichtner.
The magnetic field forces emanating from the sun virtually apply the brakes to the plasma current,
which allowed it to accumulate particles. As in a traffic jam, the probability of a "clash" is larger,
and also of an increase in the electronic exchange.
Tense wait for more data
"These initial results of the IBEX mission is a milestone on the path to a deeper understanding of the heliosphere and the galactic environment, as well as conditions of life on Earth, according to Horst Fichtner, whose group has long been researching the heliosphere. The findings on the heliosphere could also be applied to other stars, and help to understand the importance of stellar heliospheres to exo-planets outside our solar system. The IBEX measurements also show the first signs of a temporal variability of the flow of Neutralatome and thus the structure of the heliosphere,
"This is what we expect on the basis of our calculations as a result of the solar activity cycle," said Dr. Fichtner.
The detection of such a variation, however, could only succeed with measurements over a longer period.
"The other measurements of IBEX, the expected minimum detection period of two years,
is likely to be extended, so we eagerly anticipate the results!
IBEX
IBEX is the latest of low-cost, rapidly developed Small Explorer missions of NASA.
Together with a team of American and international partners,
was led by the Southwest Research Institute in San Antonio, Texas,
developed and carried out the mission.
NASA's Goddard Space Flight Center in Greenbelt, Maryland, USA,
organized the Explorer program for NASA's Science Mission Directorate in Washington.
of solar wind within the Heliosphere against high energy cosmic radiation,
such as gamma rays. shielding life on this planet (and other planets) from such radiation.
I would like to discuss here the implications of this discovery for optical and radio astronomy.
specifically the probability of attenuation and filtering of stellar radiowave and visible light
emissions from stars outside the Heliosphere.
Main Article from the website of
The Insitute for Physics and Astronomy
Ruhr University Bochum, Germany
URL: http://www.pm.rub.de/pm2009/msg00331.htm
for those of you who cannot read german
I have translated the text into english here :
The protective cocoon of the solar system
NASA probe reveals unexpected structures
Ruhr University Bochum Scientist Presents Two Papers
The solar wind envelops our solar system like a cocoon:
This continuous plasma stream emanating from the sun, protects us from the interstellar medium,
primarily from cosmic radiation at the boundry of the Heliosphere.
the NASA probe IBEX (Interstellar Boundary Explorer) for the first time
delivered measurements of energetic hydrogen atoms from this region, and also a surprise:
They suggest completely unexpected structures in the flow of these particles.
All previous calculations have excluded the magnetic field of the interstellar medium
so no one had expected such a strong influence.
Dr. Horst Fichtner (Institute for Theoretical Physics - Ruhr University Bochum)
presents these observations, and improved models of the cocoon,
to international colleagues, in two scientific articles.
Electron exchange at the edge of the heliosphere
Last October the IBEX probe was launched into Earth orbit with new detectors
pointed away from Earth into space,
recording as many high-energy hydrogen atoms from all directions per unit of time.
Gradually, as IBEX scanned the entire sky and delivered the first full-sky map of the particle flux,
conclusions about the physical processes at the outer edges of our solar system revealed:
On the edge of the heliosphere - plasma cocoons resulting from solar wind in the interstellar medium,
the solar wind consists mostly of fast moving protons,
while the interstellar medium to a large extent consists of slow moving hydrogen atoms.
When they come very close, there is a certain probability of electron exchange,
with electrons moving from slow hydrogen atoms to fast moving protons.
"When the particles exchange roles," explains Dr. Fichtner,
"the fast proton converting to fast hydrogen atom and vice versa.
The result of this exchange, we can. Measure '.
Calculation without the interstellar magnetic field
The result of such measurements obtained from IBEX, however, surprised the scientists.
It responded only partially to the previously calculated theoretical models
that were based on the assumption that the flux of energetic atoms is essentially determined by the solar wind.
It was instead a "diagonal" of the sky map with edge bands of strong intensity,
ie relatively large number of exchange processes between slow and fast neutral,
charged particles.
"Now we know why," said Horst Fichtner. "This band fits the magnetic field in the interstellar medium.
This size was previously neglected in the model. "
New scenarios
The second contribution of Science, the researchers are now designing scenarios to explain the discovered facts.
"We suspect that the dynamic role of the magnetic field
leads to a compression of the heliosphere at the boundry, " said Fichtner.
The magnetic field forces emanating from the sun virtually apply the brakes to the plasma current,
which allowed it to accumulate particles. As in a traffic jam, the probability of a "clash" is larger,
and also of an increase in the electronic exchange.
Tense wait for more data
"These initial results of the IBEX mission is a milestone on the path to a deeper understanding of the heliosphere and the galactic environment, as well as conditions of life on Earth, according to Horst Fichtner, whose group has long been researching the heliosphere. The findings on the heliosphere could also be applied to other stars, and help to understand the importance of stellar heliospheres to exo-planets outside our solar system. The IBEX measurements also show the first signs of a temporal variability of the flow of Neutralatome and thus the structure of the heliosphere,
"This is what we expect on the basis of our calculations as a result of the solar activity cycle," said Dr. Fichtner.
The detection of such a variation, however, could only succeed with measurements over a longer period.
"The other measurements of IBEX, the expected minimum detection period of two years,
is likely to be extended, so we eagerly anticipate the results!
IBEX
IBEX is the latest of low-cost, rapidly developed Small Explorer missions of NASA.
Together with a team of American and international partners,
was led by the Southwest Research Institute in San Antonio, Texas,
developed and carried out the mission.
NASA's Goddard Space Flight Center in Greenbelt, Maryland, USA,
organized the Explorer program for NASA's Science Mission Directorate in Washington.
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