That's no sunspot. It's the International Space Station (ISS) caught passing in front of the
Sun. Sunspots, individually, have a
dark central umbra, a lighter
surrounding penumbra, and no Dragon capsules attached. By contrast, the ISS is a complex and multi-spired
mechanism, one of the largest and most complicated spacecraft ever created
by humanity. Also, sunspots circle the Sun, whereas the ISS orbits the Earth. Transiting the Sun is not very unusual for the ISS, which orbits the Earth about every 90 minutes, but getting one's
location, timing and equipment just right for a great image is rare. The featured picture combined three images all taken from the
same location and at nearly the same time. One image -- overexposed -- captured
the faint prominences seen across the top of
the Sun, a second image -- underexposed -- captured the complex texture of
the Sun's chromosphere, while the third image
-- the hardest to get -- captured the space station as it shot across the Sun in a
fraction of a second. Close inspection of the space
station's silhouette even reveals a
docked Dragon Crew capsule.
.