Erm. nice thought and possible explanation but theres no way cosmic dust could cause some of the anomolies and wierd orbs complete with trails that I have seen (or seen pictures of!)

Additionally, how would you explain cosmic dust getting inside my car that was being renovated inside a sealed lockup unit? (second floor down a ramp like an underground car park type affair)

Because thats where I accidentally got 2 of my best Orb ohotos EVER!! complete with a large trail and a shadow behind it proving it is not anything on the camera lense

I was taking photos as I am selling the car and didnt notice the Orb until I loaded them up to print them!