New Aurora Pictures: Sky Shows Sparked by Sun Eruption

Explosive Aurora

Photograph by Thilo Bubek

Sparked by charged particles that had been ejected by the sun three days earlier, an aurora borealis streaks into view in the wee hours of September 15 over Ersfjord, Norway. The same night, similar shows enlivened skies over northern Canada and elsewhere in Europe.

When a charged-particle cloud enters the upper atmosphere of Earth, it smashes into and breaks up gas molecules, creating the northern lights (or in the Southern Hemisphere, the southern lights).

"Like gas inside a neon sign, as the atoms smash together they begin to glow—producing a great light show," Manuel said.

The colors a sky-watcher sees depends on what type of gas is being hit and how high it is. For example, the green aurora pictured was the result of oxygen-atom collisions about 60 to 120 miles (100 to 200 kilometers) up.

(Related: "Light Pillar Pictures: Mysterious Sky Shows Explained.")

Published September 21, 2010

Curtains on the Clouds

Photograph by Thilo Bubek

Northern lights, or aurora borealis, stride across clouds above Ersfjord, Norway, shortly before 1 a.m. on September 15.

The display was all the more impressive because the moon had already set, scientists say. When it's above the horizon, the moon can wash out all but the most intense of displays with its light.

(Also see "Aurora 'Power Surges' Triggered by Magnetic Explosions.")

Published September 21, 2010

Bridge of Sighs

Photograph by Thilo Bubek

An aurora borealis appears to touch down on an illuminated bridge in Sommarøya in northern Norway on September 8.

In addition to the September 11 coronal mass ejection (CME)—a giant bubble of charged solar particles—multiple bursts of solar magnetic activity shot CMEs toward Earth in the first few days of September.

The Solar Dynamics Observatory caught sight of the initial explosive flare emanating from a giant group of sunspots. The flare sent a CME racing toward Earth at 250 miles (400 kilometers) per second. When the particles smacked Earth's magnetic field on the eighth, auroral sparks flew.

See more pictures and wallpapers of aurorae >>

Published September 21, 2010