From Wikimedia. The original image is heavily spotted throughout as well as having other flaws that I removed with Photoshop. The image became noticeably darker in the zones where I had removed the spots. There were spots of all sizes reminiscent of Swift's jingle,
"Big fleas have little fleas upon their backs to bite 'em.
And little fleas have lesser fleas and on ad infinitum."
So there are small spots remaining in their manifold thousands.