From Live Science:

The first photos from yesterday’s total solar eclipse are here, and they’re spectacular.
Captured Wednesday (Aug. 12) by NASA scientists during a special eclipse livestream from Spain, the images show the moon completely blocking the visible surface of the sun, plunging the daytime sky into twilight for roughly 90 seconds and allowing our star’s elusive corona (its wispy outer atmosphere) to shine through. In this incredible image taken with a solar-filtered telescope, the moon appears as a black circle, cloaking the sun. The white spikes of light encircling the moon are the corona, a mysterious part of the sun that is rarely visible to the naked eye. (Why is it so mysterious? For one thing, the corona is millions of degrees hotter than the sun’s surface, and scientists aren’t sure why.)