Black flying saucer caught over Halifax, UK

On January 22, 2016, a person was walking his dog in a park located in Halifax (United-Kingdom) when he has photographed a black disc-shaped UFO in the sky. What is it?

Witness statement:

On Friday early evening i was walking my dog in the local park when i noticed that the moon look good in the sky. Using my samsung galaxy S4 i took 2 photos (with a gap of about 20 secs. between the pics) of the moon through the tree's, then put my phone away and forgot about it until today.

I checked my photo's today and spotted something strange on the 2nd of the 2 pics taken. There seemed to be something passing (at speed) in front of the moon. I zoomed into this object and found it to be saucer shaped. I do not know how big or how far away the object was. It wasn't generating any noise that i could hear.

It could have been a bird as i was in a wooded area but at the time i never noticed anything whilst taking the photo's.

Sorry if I've wasted anyone's time but i thought i would report it just in case.