Many of these photos are copyright protected by https://500px.com/cmoonview
Not citing the source of photos, or using copyrighted photos, is plagiarism. Here is a post on why this is bad, and here is how easy it is to find allowed photos.
In addition, this has nothing to do with the steemitphotochallenge, as these are not your photos.
Please also refrain from using #photography for posting other users photos without permission. Abusing tags can lead to people flagging you, even from dan himself.
Due to the above reasons I am flagging you.