AUDIO OVERLAY
SLIDE 1: INTRODUCTION: Last December, a colossal wave swept across the entire solar
surface within minutes, bulldozing everything in its path. The rare tsunami-like
shockwave formed on the heels of a major flare that erupted from an Earth-size sunspot
15 minutes earlier. Though that storm didn't have a major impact on Earth, we aren't
always so lucky. The Earth's magnetic shield protects us from the worst effects of solar
storms (and even astronauts on the International Space Station can take cover in a heavily
shielded module), but technology suffers greatly. Atmospheric and magnetic fluctuations
that the storms cause can also disable satellites, burn out transformers, and take down
power grids. One CME in 1989 left all of Quebec without power for nine hours.
SLIDE 2: LET THERE BE PUFF! (INTERACTION WITH EARTH’S ATMOSPHERIC
COMPOSITION Part 1): Eight minutes after a flare erupts, Earth's atmosphere absorbs
the radiation pulse. This pulse produces extra ions and electrons, causing the atmosphere
to puff out. The expanded atmosphere increases drag on satellites and degrades radio and
GPS signals. Apart from disrupting cellular calls and television broadcasts, this can
interfere with air-traffic control GPS-based systems by throwing of the calculations of
airplanes’ locations and velocities. But the worst is yet to come.
SLIDE 3: AURORA BOREALIS IS CROSING THE BORDER (INTERACTION WITH
EARTH’S ATMOSPHERIC COMPOSITION Part 2): Potentially more destructive than
a flare's radiation pulse, Coronal Mass Ejections boost the speed of the solar wind and
create a shockwave of energetic protons. That shockwave distorts Earth's magnetic
shield, and the protons stream down on the poles creating geomagnetic disturbances like
the Northern Lights. During the 1958 Solar Maximum, for example, a disturbance that
was similar to and classified as the Northern Lights was seen at three different times in
Central Mexico. Tiberius Caesar mistook their red glows for a fire in progress and
dispatched an army to Ostia in 34 A.D. to inspect damage.
SLIDE 4: STOP! HAMMERTIME! (INTERACTION WITH EARTH’S MAGNETIC FIELD
Part 1): Coronal Mass Ejections pummel Earth's magnetic field like a sledgehammer 1
million kilometers wide and upset the delicate balances of trapped particles in the Van
Allen radiation belts and elsewhere within the boundaries of Earth's magnetic field. Apart
from the luminous displays of heightened Northern lights, these disturbances cause
something far more damaging. The motion of other populations of charged particles
within Earth's magnetic field causes great currents of charged particles to circulate in
space like a 10,000-kilometer-wide river. These invisible stratospheric rivers can alter the
geomagnetic field temporarily and produce "magnetic storms", which can disrupt shortwave communications for hours at a time.
SLIDE 5: MAGNETIC STORMS (INTERACTION WITH EARTH’S MAGNETIC FIELD Part
2): English physicist Michael Faraday discovered in his lab that, if you take a magnet and
move it near a loop of wire, electrical current flows in the wire. The moving field induced
a corresponding motion of charge in the wire. Faraday's "magnetic induction" soon was
put to use in the first electric generator. Exactly the same thing happens when a
“magnetic storm” thunders through the Earth’s magnetic field, affecting thousands of
kilometers of underwater cabling as well as thousands of square kilometers of power
grids. Even worse effects can take place at higher latitudes. In August 1972, a 230,000volt transformer at the British Columbia Hydroelectric Authority blew up when shifting
magnetic fields induced an intolerably large current spike. On March 13, 1989, a
magnetic storm plunged Quebec into a complete power blackout, affecting millions.
SLIDE 6: SOLAR STORMS ARE A DRAG (IMPACT ON ORBITING SATELLITES Part 1):
Apart from the effects felt on the surface due to interactions with Earth’s atmosphere and
magnetic field, there are also very serious effects that are felt high above the surface,
where we have numerous orbiting satellites that regulate everything from television and
phone calls to the Global Position System. Most of these satellites are in Low Earth
Orbit, only a few hundred kilometers above the surface, and when the atmosphere puffs
out due to the extra ions and electrons caused by the solar storms, the added drag is
enough to upset the delicate orbit in which they are placed. Before these effects became
apparent and measures were beginning to be made against them, they resulted in the
premature demise of such satellites as the Solar Maximum Mission in 1990 and Skylab in
1979
SLIDE 7: WORKING AGAINST FRICTION (IMPACT ON ORBITING SATELLITES Part 2):
Following the demises of LEO satellites due to drag, all planned and current objects
designed for LEO will have to be periodically reboosted following Solar Storms, among
them the currently in-progress International Space Station. Atmospheric friction causes
other headaches. During the Quebec blackout in March 1989, the U.S. Space Command
had to recompute orbits for more than 1,300 objects affected by momentarily increased
air resistance. Nonetheless, LEO is considered prime orbital real estate for the latest
generations of communication satellite networks. One of the biggest problems arises from
the fact that it is currently impossible to predict just how much drag will result from solar
storms and for how long they will affect LEO orbits, which means that all the reboosting
calculations have to be performed after the storms themselves have passed.
SLIDE 8: LOOKING ON THE BRIGHT SIDE (IMPACT ON ORBITING SATELLITES Part
3): Almost every day for two weeks in early September of 2005, solar flares issued from
a giant sunspot named "active region 798/808." X-rays ionized Earth’s upper atmosphere.
Solar protons peppered the Moon. It was considered to be a bad time to be in space, but
studies show that there might be a bright side to CMEs. During the storms, something
strange happened onboard the International Space Station (ISS): radiation levels dropped.
"The crew of the ISS absorbed about 30% fewer cosmic rays than usual," says Frank
Cucinotta, NASA's chief radiation health officer at the Johnson Space Center. "The
storms actually improved the radiation environment inside the station." When cosmic
rays hit Earth's upper atmosphere, they produce a shower of secondary particles that can
reach the ground. By monitoring these showers he noticed, contrary to intuition, that
cosmic ray doses dropped when solar activity was high. Coronal Mass Ejections that hurl
their way to Earth contain not only gas but also magnetic force fields, knots of magnetism
ripped away from the sun by the rupture of the sunspot. Magnetic fields deflect charged
particles, so when a CME sweeps past Earth, it also sweeps away many of the
electrically-charged cosmic rays that would otherwise strike our planet. This is known as
the "Forbush Decrease."