A
coronal mass ejection (CME) is a significant release of plasma and
accompanying magnetic field from the corona of the sun. CME's often
follow solar flares and are normally present during a solar
prominence eruption. Do they hit earth? Sure – one most recently
in 1859. What would happen if a CME strikes again?
The
solar storm of 1859 (also known as the Carrington Event) was a
powerful geomagnetic storm during Solar Cycle 10 (1855–1867). A
solar coronal mass ejection hit Earth's magnetosphere and induced the
largest geomagnetic storm ever recorded on September 1–2, 1859. The
storm caused strong auroral displays and wrought havoc with telegraph
systems, essentially frying all the lines. A solar storm of this
magnitude occurring today would cause unimaginably widespread
electrical disruptions, blackouts and damage due to extended outages
of the electrical grid.
A
solar storm in 2012 was of similar magnitude, but it passed Earth's
orbit without striking the planet, missing us by nine days. If the
huge solar eruption in 2012 had hit the Earth, the effects would have
been so devastating that those of us remaining would still be
recovering from it. A huge CME or cloud of hot plasma erupted from
the sun on July 23, 2012. The CME did go through Earth's orbit, and
had it happened only nine days earlier, our planet would have been in
the way and faced severe technological consequences.
There
would have been three waves of damage associated with the extreme
solar storm. First, X-rays and ultraviolet radiation from the solar
flare would have produced radio blackouts and GPS navigational
errors. The second part would have seen satellites fried by energetic
particles like electrons and protons, arriving only minutes to hours
later. Finally, magnetized plasma from the CME would have struck our
planet within the next day. Power blackouts would have been
devastating, wiping out the power grid, making it difficult to even
flush the toilet because most urban areas use electric water pumps.
Earth and its inhabitants were incredibly fortunate that the 2012
eruption happened when it did.
Experts generally expect a bad solar
storm to reach Earth about once every century. Scientists drilling at
the poles and taking ice core samples see the evidence of large solar
flares hitting the Earth every 100-150 years. It seems we are
overdue. A solar storm of the same magnitude as 1859 and 2012
occurring today would cause widespread electrical disruptions,
blackouts and damage due to extended outages of the electrical grid.
Solar
Cycle 25 should begin between mid-2019 and late 2020 and should reach
its maximum between 2023 and 2026, when between 95 and 130 sunspots
are projected. What are the chances that we experience a CME in the
next decade? Probably good. It is all a roll of the dice, but there
is an absolute 100 percent certainty it will happen at some time in
the future.
How
many people could die due to a large flare? When scientists are
asked, their response is that should a large electromagnetic pulse
(EMP) or geomagnetic disturbance (GMD) event occur due to a CME, as
many as 9 out of 10 people in the United States could die.
Civilization as we know it would essentially end along with our
technological capabilities. But who knows? So, on that cheery note,
open another bottle and pour me a glass, and would you pass the
pretzels please?
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