Cambridge, MA- At approximately 5:54 a.m. EST this morning, a gigantic solar
flare erupted from sunspot 10486 on the surface of the Sun. That explosion
blasted tremendous amounts of energy and matter into space, sending a
coronal mass ejection (CME) directly toward the Earth. That CME is predicted
to create a major geomagnetic storm when it reaches our planet on Thursday.

“This is the real thing,” says John Kohl, a solar astrophysicist at the
Harvard-Smithsonian Center for Astrophysics (CfA) and principal investigator
for the Ultraviolet Coronagraph Spectrometer on board NASA’s Solar and
Heliospheric Observatory (SOHO) spacecraft. “The eruption was positioned
perfectly. It’s headed straight for us like a freight train, so a major
geomagnetic storm is bound to happen when it reaches us on October 29th or
30th.”

“Last week’s CME hit the Earth with only a glancing blow,” says Kohl,
although it was sufficient to disrupt airline communications. “Today’s
eruption was pointed directly at us, and is expected to have major effects.”

“This is the strongest flare we’ve seen in the past 30 years,” says Leon
Golub, CfA astrophysicist and author of “Nearest Star: The Surprising
Science Of Our Sun.” Today’s solar flare was classified as an X18-category
explosion, meaning that it can trigger planet-wide radio blackouts and
long-lasting radiation storms.

“We are waiting for the prediction of the geomagnetic storm level from NOAA
(the National Oceanic and Atmospheric Administration),” says Kohl. “What we
know at this point is that the flare was nearly perfectly positioned near
the center of the Sun, and that a halo coronal mass ejection has left the
Sun and is heading toward the Earth. The geomagnetic storm is likely to be a
strong one, and will last about 24 hours.”

NOAA classifies geomagnetic storms on a scale from 1 to 5. Initial
indications show that this has the potential to be a G5 storm – the top of
the scale. The most benign effect of such a storm would be bright auroras
visible from more southern latitudes than usual. However, the geomagnetic
storm triggered by the CME also could interfere with satellite
communications; disrupt power grids (as occurred in the 1989 Quebec
blackout); even short out orbiting satellites, rendering them permanently
inoperable.

“We’ve already had to shut down our SOHO instrument for safety reasons. It’s
getting blasted by high-energy particles from this solar flare,” says Kohl.
“Of more concern, geosynchronous communications satellites are likely to be
affected.” In California, where raging wildfires have damaged many
microwave communication antennas on the ground, satellite communications
have been crucial to emergency efforts. Emergency personnel should be
prepared for potential disruptions and communication interference.

“There’s no direct danger to people on the ground,” Kohl adds, “and I’m sure
that NASA is monitoring the situation for any potential effects on the space
station crew, and that they are taking appropriate precautions.”

According to NOAA, a G5-class geomagnetic storm can have the following
effects:

Power systems: Widespread voltage control problems and protective system
problems can occur, some grid systems may experience complete collapse or
blackouts. Transformers may experience damage.

Spacecraft operations: May experience extensive surface charging, problems
with orientation, uplink/downlink and tracking satellites.

Other systems: Pipeline currents can reach hundreds of amps, HF (high
frequency) radio propagation may be impossible in many areas for one to two
days, satellite navigation may be degraded for days, low-frequency radio
navigation can be out for hours, and aurora has been seen as low as Florida
and southern Texas (typically 40 degrees geomagnetic lat.).

Solar astronomers say to stay tuned. This eruption is coming our way!

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for
Astrophysics is a joint collaboration between the Smithsonian Astrophysical
Observatory and the Harvard College Observatory. CfA scientists, organized
into six research divisions, study the origin, evolution and ultimate fate
of the universe.

For more information, contact:

David Aguilar
617-495-7462
daguilar@cfa.harvard.edu

Christine Lafon
617-495-7463
clafon@cfa.harvard.edu