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A region with the lowest intensity of the Earth's magnetic field, located over the South American continent, has effects that can be felt from a hundred kilometers altitude
When the Hubble Space Telescope pbades through it, its instruments are extinguished.
Ignoring it can be fatal. In 2016, a brand new Japanese satellite, the powerful Hitomi, designed to study black holes and clusters of galaxies, infiltrated it inconsiderately and paid the price: it collapsed and shattered in the despair of Japanese astronomers.
When the International Space Station (ISS), in orbit around the Earth, crosses its territory, astronauts on mission at the station report strange visions: explosions of light, such as fires. artifice.
We are talking about the Magnetic Anomaly of South America (AMAS), a region of lower intensity of the Earth's magnetic field, located above South American territory, whose most obvious effects may be to be felt at a hundred kilometers altitude.
It has been identified a century ago and, although it affects the functioning of artificial satellites – with economic and human impact – the anomaly is little known and does not receive the l & # 39; deserved attention by the international scientific community, say Brazilian scientists.
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In an interview with BBC News Brazil, three researchers from the National Institute of Especial Research (Inpe), to São José dos Campos (SP), explains in turn the phenomenon – and why it interests us.
"The Earth is enveloped in a magnetic field generated internally on the planet and protects us from all that comes from space",
. says the physicist Antônio Lopes Padilha
This magnetic field, explains Padilha, is generated in the liquid core of the Earth, thousands of kilometers deep. The core is formed mainly of iron and nickel. The conditions of the place, where the temperature and pressure are very high, generate a large amount of free electrons that are constantly circulating.
"The movement of these electrons generates an electric current and this current generates the Earth's magnetic field."
The magnetic field, however, is not the same over the entire surface of the planet. In some areas it is stronger than in others.
Image caption
Imagine if the communication satellite has stopped transmitting at this point in time? Satellites are much more vulnerable to particle precipitation when they cross the Magnetic Anomaly of South America
"The region of the South American Anomaly, historically called the South Atlantic Anomaly, is the region of least intensity of the magnetic field on the surface of the Earth," says Padilha .
The dimensions of this "hole" vary according to the altitude, it explains […]
"It covers a large part of the South American continent, its presence causes certain phenomena, mainly in the so-called ionosphere region , above 100 km Inpe team
At 500 km height (the approximate orbit of the International Space Station), the AMAS area extends between -50 ° and 0 ° of geographic latitude and -90 ° and + 40 ° of longitude Periodically, sudden changes in the magnetic field of the sun cause a sudden release of large amounts of energy
How are we?
Periodically, sudden changes in the magnetic field of the Sun cause a sudden release of large amounts of energy.These phenomena, known as solar explosions, release electromagnetic radiation that spreads at the speed of e light, reaching the Earth in 8 minutes. They also accelerate particles out of the Sun, which can generate so-called magnetic clouds, or coronal mbad ejections (CMEs). The cloud moves in space and sometimes reaches the Earth.
There are particles – protons and electrons. It is a mbad of plasma that takes one to three days to reach the Earth, and when it does, it causes magnetic storms, precipitating these highly energetic particles on the planet.
"The most beautiful effect of magnetic storms is the aurora (polar): when there is a dawn, one can search a few days before the solar explosion", explains the Brazilian engineer and Doctor of Space Science Clézio Marcos De Nardin, Director General of the Brazilian Space Weather Program, Embrace / INPE.
As the magnetic field that protects the Earth from these particles is weaker in the AMAS region, when there are solar explosions, the risks that the energy particles released by the Sun cross the field Magnetic in this area are much larger. : Anomaly satellites are much more affected by radioactive particles – and require additional protection. [1965909] Image caption
Satellite images may be affected by the anomaly
"The amount of particles reaching the satellites that go into the anomaly is much greater here than in any other part of the globe, except for aurora regions," De Nardin explains.
"We know, for example, that Austrian satellites are extinguished when they enter the magnetic anomaly and are closed when they go out at the other end. avoid problems in the computer devices, because such a particle can damage the computer or change the attitude of the satellite, leading to its loss. "
C is what is arrived at the Japanese satellite Hitomi, explain the researchers.
"It was an X-ray satellite, an astrophysical satellite." He pbaded into the anomaly and suffered so much particle bombardment that he was lost. He began to turn around the axis and he crashed.After, the Japanese Space Agency came to the public explain why they had lost the satellite, they did not take into account the Predictions of space weather, which predicts the arrival of a magnetic cloud, which would increase the precipitation of particles in the anomaly, "says De Nardin.
As far as we know, the importance of the magnetic anomaly for us humans is badociated with the potential risks that it brings to the planet's satellite network – explains the scientist.
And as modern societies are increasingly based on artificial satellites for multiple activities – communications, navigation, meteorology, defense, Earth observation and exploration of the Universe – the search for strategies to dodge Anomaly becomes more and more vital
"In the last ten years we have developed a lot of weather forecasts in the space," says De Nardin.The program Embrace, led by him, is among the first five in the world to predict the space weather
Dribble the anomaly
Predicting space time is important for the entire planet – but it is fundamental near the poles (where magnetic storms can affect the systems of transmission of energy) and in the region of the magnetic anomaly
At AMAS, what is at stake, it is the large number of satellites that circulate in the zone or stationed there
"For example, it is around the geographical equator that most communication satellites and other geostationary meteorological satellites reside," De Nardin explains.
Aurora borealis occurs after solar explosions, which in turn generate magnetic storms. The north and south poles are the regions of least intensity of the Earth's magnetic field. Then there is the AMAS region.
"Satellite imagery uses three main strategies to" dribble "the anomaly."
"Imagine we do not expect tornadoes in the Gulf of Mexico and the United States?"
"First, build more robust systems that resist the precipitation of particles." Second, designing on-board computers that allow the satellite to operate longer without control, with larger internal disks capable of storing more information, to control operations so as not to coincide with magnetic storms (which is done on the prediction of space weather), "says De Nardin.
Aircraft are the most affected in the anomaly?
" The plane flies much lower at an altitude of 10 to 12 km , I'm talking about commercial flights.
However, there are ongoing studies on the subject, adds the physicist and doctor in space geophysics Marcelo Banik of Padua.
"Research is currently underway to try to measure AMAS effects on avionics, but we do not expect to find relevant variations: it is normal to have a higher dose in flight , because you are bigger. (19659014) Space Station
What we do know is that we will not be able to measure it. When the ISS goes into the anomaly area It is common for astronauts to see bursts of light, like shooting stars, even if they have their eyes closed.
"This does not just happen in the anomaly, but it does happens more often ", explains Banik de Padua.
Legend of the image
Legend of the image
During the pbadage of the ISS by the AMAS region, the badociated risks to solar explosions also increase
A possible explanation for this phenomenon is that the optic nerve, deep in the eye of the astronauts, would be affected by the particles that precipitate it.
In other words, a solar explosion occurred if the arrival time of the cloud of particles coincides with the pbadage of the ISS in the & [[[[[[[[[[[[[[[[[[[[[[anomalythechancesthattheyrainparticlesonthestationincreasealot"ThereisanISSshieldedroomforastronautstostayinCMEarrivalpredictions-hencetheimportanceofspaceweatherforecastingcenterssuchastheEmbrace/INPE"hesays
Extra-vehicular activities are prohibited during these periods.
"If there is extravehicular activity at the space station – that is, if the astronaut leaves the ship for repairs or experiments – and coincides with a magnetic storm at that moment, the astronaut will be much more vulnerable. "
] De Nardin points out that solar flares – and hence magnetic storms – are still a risk for the ISS and its personnel.
"Shortly after a solar explosion, the first particles to arrive are those that accelerated out of the sun immediately after radiation, they are so violent that they were baptized"
"They can cross the armor of the ISS as a knife cuts the butter, they can cross the electronic circuits, burn their memory, hit the instruments, destroy the processors "
Brazil
De Nardin says that in his lectures, a common question is: what effect will the anomaly have on human beings – in Brazil
"In principle, the precipitation of particles does not directly affect people here. There is no connection with skin cancer, none of this – we are talking about things that are important over a hundred miles. "
] But there is at least one type of possible impact. "Because the average citizen is increasingly connected to the world in real time, let's take the example of the Russian World Cup and imagine that the Brazilian national team is shooting at the goal of the last match." De Nardin
"Do you want the communication satellite to stop transmitting at this very moment?"
"Yes, if you have a magnetic storm and it is not ready for that, and if there is no other backup satellite, this could be a reality, "concludes the researcher.
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