Material from a second, more powerful ejection is expected Friday. The aurora, or northern and southern lights, are a shimmering glow in the sky caused when energetic particles from the sun strike atoms of gas in the upper atmosphere of the Earth. The Earth's magnetic field protects the planet from these solar particles, but the field dips low over the poles. For this reason, the aurora is most commonly seen at high northern and southern latitudes. Unusually powerful solar bursts can produce the blue and green lights in the night sky closer to the equator.
Experts say that the aurora is best viewed around midnight.
The corona mass ejection poses no health risk to people on the ground, but such solar bursts have been known to damage spacecraft and to disrupt electrical power grids. Most utility systems and satellites now are designed to resist such effects, however. The sun is at the peak of its 11-year cycle of intense activity. Use of this site signifies your agreement to the Terms of Service updated April 2000. Contact Online Sales Manager Gina Kaiser to inquire about becoming a sponsor.