(Update: The aurora’s active tonight. Not a big storm, but if you live in the northern U.S. and the sky’s clear, head out for a look. A G1 storm (Kp=5) is underway with arcs and faint rays low in the northern sky. The activity, spawned by a coronal mass ejection (CME) from the sun earlier this week, arrived unexpectedly early. Keep in mind the full moon may make seeing this aurora tricky. Just the same, good luck!)
If you looked up at the sun today through a safe solar filter, you’d easily make out a couple black spots. They belong to two large sunspot groups, one of which, numbered 2567, has the potential to kick out flares strong enough to rattle Earth’s magnetic defenses.
According to the NOAA space weather 3-day forecast, both 2565 and 2567 have significant flare potential though the latter, with its messy magnetic field, has a greater chance for strong M-class solar flares. Should flares occur, the subatomic stew would make a beeline for Earth because the spots are near the center of the sun’s disk and facing our direction. Of course, that might mean aurora. Let’s wait and see.
In other sun-inspired news, on engineers instructed NASA’s Solar Dynamics Observatory (SDO) to roll 360° on one axis. SDO dutifully performed the seven-hour maneuver, while still taking pictures every 12 seconds. Strung together, they show the sun doing the impossible – spinning like a pinwheel! While merely a reflection of the observatory’s movement, there’s something oddly transfixing about it.
SDO flips twice a year in order to make precise measurements of the edge of the sun called the solar limb. That’s because our star isn’t a perfect sphere but a boiling globe with distortions in its outline, making it hard to pin down exactly where the sun’s edge is, according to NASA. The biannual roll lets each part of the camera look at the solar limb to help scientists determine its precise shape.