Three in a row! The same “hole” in the sun’s corona, seen here as the dark, keyhole-shaped blob at the center of the disk, may be spark a third successive round of aurora tonight. Holes are places where the solar particle wind can stream freely and swiftly away from the sun. They show best in photos taken in far ultraviolet light like these by NASA’s Solar Dynamics Explorer. NASA / SDO
A trifecta is within our grasp. The same coronal hole that’s been around since August is facing Earth again and blasting us with a wind of high-speed particles. This persistent feature sparked both the late August and September auroras. Why the repeat? The sun rotates on its axis once about every 4 weeks, making this the third time in a row we’ve come face to face with the hole.
This aurora, photographed on Aug. 31, 2019, originated from the same coronal hole now facing Earth. Holes can persist for months and spawn repeat auroras. Bob King
Space weather forecasters predict a minor geomagnetic storm with Kp index reaching 5 starting this afternoon (Oct. 24) and continuing through the night. Peak “winds” are expected to reach 375 miles per second ...