Fast-Growing Sunspots

These sunspots didn't exist when the weekend began. Now they are many times larger than Earth. NASA's Solar Dynamics Observatory recorded their rapid development in this two-day movie:

NOAA has numbered these active regions AR3582 (right) and AR3583 (left). Both show signs of developing mixed-polarity magnetic fields that could pose a threat for Earth-directed solar flares. If their rapid growth continues apace, they will be the largest spots on the solar disk by the end of today.

SOURCE: https://www.spaceweather.com/