Click on the image for a larger animation . There's no cause for alarm. If the shock wave is very strong, as this one might be, it can compress the magnetosphere and unleash a geomagnetic storm. In extreme cases, such storms can induce electric currents in the Earth that interfere with electric power transmission equipment. Satellite failures are possible, too.
Geomagnetic storms can also trigger beautiful aurorae.
Whether or not an auroral display is triggered by the blast depends on the orientation of the magnetic field within the CME's approaching shock wave. Magnetic fields with a southward directed component can create a weak point in Earth's magnetic defenses and make auroras more likely. The bright object near the horizon is the Moon. Also visible in the background are the Pleiades, Taurus, and Orion. The exposure time was one minute on Kodak Elite 100 slide film.