Volatile Sunspot Makes Third Trip around the Sun

One of the Sun's most recently active sunspot regions has made its third migration around the star, NASA reported Friday.

Sunspots are magnetically strong regions of the solar surface that are generally cooler than their surrounding regions, leading to their dark appearance on the solar surface.

With each revolution of a sunspot, which NASA said occurs about every 27 days, it takes on a new name. Thus, the active sunspot region now named AR11990, has previously been known as AR11967 and AR11944.

Scientists track sunspots because they are the origin of solar flares and coronal mass ejections (CMEs). Earlier this week, this same sunspot region belted out one of the most powerful solar flares in recent memory. Solar fares are powerful bursts of radiation. Although they cannot pass through the Earth's atmosphere and harm humans on the ground, the radiation can disturb GPS systems and other radio equipment.

The X4.9-class solar flare was reported by NASA's Solar Dynamics Observatory (SDO) at 00:49 GMT on Tuesday, Feb. 25 (7:49 p.m. Monday, Feb. 24 EST). The event, which the SDO said occurred in sunspot region AR 11990, lasted 22 minutes.

The resulting CME that erupted from the sunspot at a blazing velocity of 4.4 million mph (nearly 2,000 kilometers per second), just grazed by Earth, producing some incredible aurora borealis over Greenland, Iceland and parts of Europe, according to Spaceweather.com, which published a photo of the aurora. Had the CME been a direct hit, it could have caused significant damage to satellites and electrical equipment.

According to NASA sunspot region AR 11990 has produced two significant X-class solar flares, as well as numerous mid-level and smaller flares.

Sunspots, NASA, said are generally fleeting, lasting only a few weeks between appearances.

"Studying what causes active regions to appear and disappear over time, as well as how long they remain stable, is key to understanding the origins of space weather that can impact Earth's technological infrastructure," NASA said in a statement.