|The GRAPES-3 muon telescope, the largest and most sensitive cosmic ray monitor recorded a burst of galactic cosmic rays that indicated a crack in the Earth’s magnetic shield. Credit: TIFR|
by Science Daily Staff Writer, November 3rd 2016
The GRAPES-3 muon telescope recorded a burst of galactic cosmic rays of about 20 GeV, on 22 June 2015 lasting for two hours. The burst occurred when a giant cloud of plasma ejected from the solar corona, and moving with a speed of about 2.5 million kilometers per hour struck our planet, causing a severe compression of Earth’s magnetosphere from 11 to 4 times the radius of Earth. It triggered a severe geomagnetic storm that generated aurora borealis, and radio signal blackouts in many high latitude countries.
The burst occurred when a giant cloud of plasma ejected from the solar corona, and moving with a speed of about 2.5 million kilometers per hour struck our planet, causing a severe compression of Earth’s magnetosphere from 11 to 4 times the radius of Earth. It triggered a severe geomagnetic storm that generated aurora borealis, and radio signal blackouts in many high latitude countries.
Earth’s magnetosphere extends over a radius of a million kilometers, which acts as the first line of defence, shielding us from the continuous flow of solar and galactic cosmic rays, thus protecting life on our planet from these high intensity energetic radiations. Numerical simulations performed by the GRAPES-3 collaboration on this event indicate that the Earth’s magnetic shield temporarily cracked due to the occurrence of magnetic reconnection, allowing the lower energy galactic cosmic ray particles to enter our atmosphere. Earth’s magnetic field bent these particles about 180 degree, from the day-side to the night-side of the Earth where it was detected as a burst by the GRAPES-3 muon telescope around mid-night on 22 June 2015. The data was analyzed and interpreted through extensive simulation over several weeks by using the 1280-core computing farm that was built in-house by the GRAPES-3 team of physicists and engineers at the Cosmic Ray Laboratory in Ooty.
This work has recently been published in Physical Review Letters.
Solar storms can cause major disruption to human civilization by crippling large electrical power grids, global positioning systems (GPS), satellite operations and communications.
The GRAPES-3 muon telescope, the largest and most sensitive cosmic ray monitor operating on Earth is playing a very significant role in the study of such events. This recent finding has generated widespread excitement in the international scientific community, as well as electronic and print media.
Source: Tata Institute of Fundamental Research
P. K. Mohanty, K. P. Arunbabu, T. Aziz, S. R. Dugad, S. K. Gupta, B. Hariharan, P. Jagadeesan, A. Jain, S. D. Morris, B. S. Rao, Y. Hayashi, S. Kawakami, A. Oshima, S. Shibata, S. Raha, P. Subramanian, H. Kojima. Transient Weakening of Earth’s Magnetic Shield Probed by a Cosmic Ray Burst. Physical Review Letters, 2016; 117 (17) DOI: 10.1103/PhysRevLett.117.171101
Massive Crack in Earth’s Magnetic Shield Discovered
by Paul Seaburn, November 5th 2016
If you’re looking for something to take your mind off of the presidential election, this might do the trick. A giant crack has been discovered in the Earth’s magnetosphere – our first line of defense against those pesky cosmic rays that bring down electrical power grids, mess up global positioning systems, garble communications and make your skin look like the last rotisserie chicken in the grocery store oven at closing time. What’s worse, the crack opened over a year ago and we’re just learning about it now. Have you forgotten about who’s running yet?
The crack was discovered by researchers at Tata Institute of Fundamental Research’s (TIFR) Cosmic Ray Laboratory in Ooty, India, using data recorded by the GRAPES-3muon telescope (Gamma Ray Astronomy PeV EnergieS 3rd establishment), the world’s largest and most sensitive cosmic ray telescope. They noticed that data from June 22, 2015, showed a two-hour-long burst of cosmic radiation ramming Earth at 2.5 million km (1.55 million miles) per hour. The burst measured 20 GeV – that’s 20 gigaelectronvolt or 20 billion electron volts.
What happens when that kind of cosmic force meets Earth’s magnetosphere? According to the report published recently in Physical Review Letters, the protective sphere surrounding the planet was severely dented from 11 to four times the radius of the Earth. Simulations created by the GRAPES-3 researchers showed that the magnetosphere cracked during the two-hour bombardment, allowing lower energy galactic cosmic ray particles to enter the atmosphere.
Didn’t anyone notice this on June 22nd, 2015? The data shows a strong geomagnetic storm occurred at the time, causing an aurora borealis and radio blackouts in high-latitude countries near the poles, but nothing disastrous. Did we take a cosmic bullet in an area that only caused a flesh wound? The study suggests this, along with a warning.
The simultaneous occurrence of the burst in all nine directions suggests its origin close to Earth. It also indicates a transient weakening of Earth’s magnetic shield, and may hold clues for a better understanding of future superstorms that could cripple modern technological infrastructure on Earth, and endanger the lives of the astronauts in space.
OK, we’re all concerned occasionally about astronauts on the ISS and Elon Musk doesn’t want the passengers on his Mars ships to arrive at the Red Planet extra-crispy, but what about us on Earth? We all know what kind of problems a loss of the electrical and communications grid can cause and none of us want to wake up to the smell of frying skin. But what’s really disconcerting is that it’s taken over a year for the news of this crack in the magnetosphere to come out. Why did it take so long? What else haven’t we been told about it?
Still worried about the election?