What Is This?

“Time is free, but it's priceless. You can't own it, but you can use it. You can't keep it, but you can spend it. Once you've lost it you can never get it back.”--Unknown

Thought this was a water spot. Maybe an airplane. Pictures before and afterwards had no other anomaly. Went to Grand Canyon and took a few pictures. Was cleaning them autocorrecting on Microsoft Picture Manager. Notice this white spot in the middle of blue sky