New Aurora Pictures: Sky Shows Sparked by Sun Eruption

New Aurora Pictures: Sky Shows Sparked by Sun Eruption

An aurora borealis, or northern lights, twists across the heavens above Ersfjord (map), Norway, in the first hour of September 15.

Three days earlier NASA's Solar Dynamics Observatory, a sun-monitoring satellite, witnessed a magnetic eruption on the sun, which unleashed a gigantic cloud of charged particles into space. The southern part of the particle cloud, or solar wind, grazed Earth's magnetic field on the 14th and 15th, resulting in a particularly good night for aurorae.

During the Northern Hemisphere's autumn and spring, solar magnetic fields are oriented in just the right way to cause "rips" in Earth's magnetic field. The resulting increase in solar wind on Earth encourages auroral sky shows but can also damage satellite technology and electrical grids on the ground.