The barrier to the particle motion was discovered inwards the Van Allen radiations belts, ii doughnut-shaped rings higher upwards public that are filled amongst high-energy electrons in addition to protons, said Distinguished Professor Daniel Baker, manager of CU-Boulder’s Laboratory for Atmospheric in addition to Space Physics (LASP). Held inwards house yesteryear Earth’s magnetic field, the Van Allen radiations belts periodically cracking in addition to shrink inwards answer to incoming liberate energy disturbances from the sun.
As the get-go meaning uncovering of the infinite age, the Van Allen radiations belts were detected inwards 1958 yesteryear Professor James Van Allen in addition to his squad at the University of Iowa in addition to were constitute to live composed of an inner in addition to outer belt extending upwards to 25,000 miles higher upwards Earth’s surface. In 2013, Baker — who received his doctorate nether Van Allen — led a squad that used the twin Van Allen Probes launched yesteryear NASA inwards 2012 to regain a third, transient “storage ring” betwixt the inner in addition to outer Van Allen radiations belts that seems to come upwards in addition to become amongst the intensity of infinite weather.
The latest mystery revolves around an “extremely sharp” boundary at the inner border of the outer belt at roughly 7,200 miles inwards height that appears to block the ultrafast electrons from breeching the shield in addition to moving deeper towards Earth’s atmosphere.
“It’s almost similar theses electrons are running into a drinking glass wall inwards space,” said Baker, the study’s Pb author. “Somewhat similar the shields created yesteryear strength fields on Star Trek that were used to repel alien weapons, nosotros are seeing an invisible shield blocking these electrons. It’s an extremely puzzling phenomenon.”
H5N1 newspaper on the dependent champaign was published inwards the Nov. 27 number of Nature.
The squad originally idea the highly charged electrons, which are looping around public at to a greater extent than than 100,000 miles per second, would tardily drift downward into the upper atmosphere in addition to gradually live wiped out yesteryear interactions amongst air molecules. But the impenetrable barrier seen yesteryear the twin Van Allen belt spacecraft stops the electrons earlier they larn that far, said Baker.
The grouping looked at a number of scenarios that could exercise in addition to hold such a barrier. The squad wondered if it powerfulness accept to exercise amongst Earth’s magnetic champaign lines, which trap in addition to command protons in addition to electrons, bouncing them betwixt Earth’s poles similar beads on a string. The too looked at whether radio signals from human transmitters on public could live scattering the charged electrons at the barrier, preventing their downward motion. Neither explanation held scientific water, Baker said.
“Nature abhors potent gradients in addition to to a greater extent than oftentimes than non finds ways to polish them out, in addition to hence nosotros would aspect some of the relativistic electrons to displace inward in addition to some outward,” said Baker. “It’s non obvious how the slow, gradual processes that should live involved inwards motion of these particles tin give the sack conspire to exercise such a sharp, persistent boundary at this location inwards space.”
Another scenario is that the giant cloud of cold, electrically charged gas called the plasmasphere, which begins most 600 miles higher upwards public in addition to stretches thousands of miles into the outer Van Allen belt, is scattering the electrons at the boundary amongst depression frequency, electromagnetic waves that exercise a plasmapheric “hiss,” said Baker. The hiss sounds similar white dissonance when played over a speaker, he said.
While Baker said plasmaspheric hiss may play a purpose inwards the puzzling infinite barrier, he believes in that location is to a greater extent than to the story. “I intend the fundamental hither is to operate along observing the share inwards exquisite detail, which nosotros tin give the sack exercise because of the powerful instruments on the Van Allen probes. If the Sun actually blasts Earth’s magnetosphere amongst a coronal volume ejection (CME), I suspect it volition breach the shield for a catamenia of time,” said Baker, too a faculty fellow member inwards the astrophysical in addition to planetary sciences department.
“It’s similar looking at the phenomenon amongst novel eyes, amongst a novel fix of instrumentation, which give us the exceptional to say, ‘Yes, in that location is this hard, fast boundary,'” said John Foster, associate manager of MIT’s Haystack Observatory in addition to a written report co-author.