No, that's a dust spot on your sensor... :p

More seriously, fantastic shots, man! I find the whole business of seeing other bodies in the solar system to be fascinating. I remember the first time I saw Jupiter's moons through my camera lens. Blew me away. I didn't actually realise at the time that you could see them from Earth that easy. This was about 30 years ago. And just the other month while Jupiter was really close again I showed my son and daughter the moons of Jupiter through my son's telescope. They were equally blown away. :)