Solar Radiation
October 23, 2003: Newly uncovered scientific data of recorded
history's most massive space storm is helping a NASA scientist
investigate its intensity and the probability that what occurred on
Earth and in the heavens almost a century-and-a-half ago could
happen again.
In scientific circles where solar flares, magnetic storms and other
unique solar events are discussed, the occurrences of September 1-2,
1859, are the star stuff of legend. Even 144 years ago, many of
Earth's inhabitants realized something momentous had just occurred.
Within hours, telegraph wires in both the United States and Europe
spontaneously shorted out, causing numerous fires, while the
Northern Lights, solar-induced phenomena more closely associated
with regions near Earth's North Pole, were documented as far south
as Rome, Havana and Hawaii, with similar effects at the South Pole.
What happened in 1859 was a combination of several events that
occurred on the Sun at the same time. If they took place separately
they would be somewhat notable events. But together they caused the
most potent disruption of Earth's ionosphere in recorded history.
"What they generated was the perfect space storm," says Bruce
Tsurutani, a plasma physicist at NASA's Jet Propulsion Laboratory.
To begin to understand the perfect space storm you must first begin
to understand the gargantuan numbers with which plasma physicists
like Tsurutani work every day. At over 1.4 million kilometers
(869,919 miles) wide, the Sun contains 99.86 percent of the mass of
the entire solar system: well over a million Earths could fit inside
its bulk. The total energy radiated by the Sun averages 383 billion
trillion kilowatts, the equivalent of the energy generated by 100
billion tons of TNT exploding each and every second.
But the energy released by the Sun is not always constant. Close
inspection of the Sun's surface reveals a turbulent tangle of
magnetic fields and boiling arc-shaped clouds of hot plasma dappled
by dark, roving sunspots.
Once in a while--exactly when scientists still cannot predict--an
event occurs on the surface of the Sun that releases a tremendous
amount of energy in the form of a solar flare or a coronal mass
ejection, an explosive burst of very hot, electrified gases with a
mass that can surpass that of Mount Everest.
What transpired during the dog days of summer 1859, across the 150
million-kilometer (about 93 million-mile) chasm of interplanetary
space that separates the Sun and Earth, was this: on August 28,
solar observers noted the development of numerous sunspots on the
Sun's surface. Sunspots are localized regions of extremely intense
magnetic fields. These magnetic fields intertwine, and the resulting
magnetic energy can generate a sudden, violent release of energy
called a solar flare. From August 28 to September 2 several solar
flares were observed. Then, on September 1, the Sun released a
mammoth solar flare. For almost an entire minute the amount of
sunlight the Sun produced at the region of the flare actually
doubled.
"With the flare came this explosive release of a massive cloud of
magnetically charged plasma called a coronal mass ejection," said
Tsurutani. "Not all coronal mass ejections head toward Earth. Those
that do usually take three to four days to get here. This one took
all of 17 hours and 40 minutes," he noted.
Right: SOHO coronagraphs captured this movie of a coronal mass
ejection (CME) heading toward Earth on Oct. 22nd. NOAA forecasters
expect the CME to cause a geomagnetic storm when it reaches Earth on
or about Oct. 24th, but not as severe as the superstorm of 1859.
Not only was this coronal mass ejection an extremely fast mover, the
magnetic fields contained within it were extremely intense and in
direct opposition with Earth's magnetic fields. That meant the
coronal mass ejection of September 1, 1859, overwhelmed Earth's own
magnetic field, allowing charged particles to penetrate into Earth's
upper atmosphere. The endgame to such a stellar event is one heck of
a light show and more -- including potential disruptions of
electrical grids and communications systems.
Back in 1859 the invention of the telegraph was only 15 years old
and society's electrical framework was truly in its infancy. A 1994
solar storm caused major malfunctions to two communications
satellites, disrupting newspaper, network television and nationwide
radio service throughout Canada. Other storms have affected systems
ranging from cell phone service and TV signals to GPS systems and
electrical power grids. In March 1989, a solar storm much less
intense than the perfect space storm of 1859 caused the Hydro-Quebec
(Canada) power grid to go down for over nine hours, and the
resulting damages and loss in revenue were estimated to be in the
hundreds of millions of dollars.
"The question I get asked most often is, 'Could a perfect space
storm happen again, and when?'" added Tsurutani. "I tell people it
could, and it could very well be even more intense than what
transpired in 1859. As for when, we simply do not know," he said.
