Trent Mason, 22, and Jack Holdsworth, 21, were stargazing when they reportedly saw an eerie object change colour and move around the sky for more than two hours.
They were said to be shocked as the object made circular and triangular patterns in the sky and changed colour from white to orange.
The two friends were camping near to the Ribblehead railway viaduct when they claim the object appeared.
Mr Mason said: “It just popped up on the horizon, then disappeared back where it came from. I was not sure if I saw it but looked at Jack and his face was white
“It was there one minute, then next it lit up like a bolt of lightening. It was like a flash and whoosh, it was gone. If I’d blinked I would have missed it.
“It was absolutely incredible. The stars were dots in the night sky and this was the size of a 5p. It was hard to judge how far away it was but it was definitely higher than the hills.”
The Yorkshire Dales area is said to attract thousands of hikers every year.
Yorkshire based UFO researcher Philip Mantle, a former director of investigations for the British UFO Research Association, said: “For decades now UFO sighting reports have come across my desk from areas in and around the Yorkshire Dales national park and surrounding areas.
“It therefore comes as no surprise to learn of the sighting by Mr Mason and Mr Holdsworth over the world famous Ribblehead viaduct.
“Over the last few years UFO sighting reports in this area have been few and far between, however, for whatever reason, 2017 has seen a sharp upturn in reports in this area.
“Why this is, I have no idea, but the sighting reported by these two gentlemen fits with other sightings I have had from this general area in the past.”