A team of American scientists has observed an unprecedented space weather phenomenon: rains of ultrafast electrons emanating from the radiation belts encircling our planet.
Phenomena on an unprecedented scale
Electron showers are nothing new, nor are they particularly problematic most of the time. The electrons and other charged particles accumulate in the magnetosphere from Terre, literally bouncing between the north and south poles. Wind and solar storms can rip some of them off, sending them into Earth’s atmosphere where they can contribute to auroras.
Researchers from theuniversity of california have discovered a new mechanism that causes electron rain on an unprecedented scale. In this specific case, electromagnetic waves sibilant » pass through the plasma of the magnetosphere and accelerate the electrons it contains, leading to the rapid and massive fall of the latter on the Earth’s atmosphere.
Detailed in the review Nature Communicationsthis work involved the analysis of data collected by the pair of microsatellites ELFINplaced in low Earth orbit and capable of detecting and measuring electron rain, and of the satellite network THEMIS from NASA, which made it possible to establish the whistling wave levels. The combination of these two sets revealed a clear link between the latter and the showers of ultrafast electrons, logically proving to be more frequent during solar storms.
An essential consideration
According to the researchers, it is important that our models take into account such space weather phenomena, which can disrupt satellites in low orbit, damage devices on board passing spacecraft or affect the health of astronauts.
« Although space is commonly thought to be separate from our upper atmosphere, the two are inextricably linked. “, remember Vassilis Angelopoulos, lead author of the study. ” Understanding the nature of these links is essential, both for the vehicles in orbit, but also for humans.. »
