Some believe in them, others think they're make believe.
But you might be surprised just how many people in the east reckon that UFOs do exist.
Almost half the population in our region are said to believe in aliens and it might have something to do with the sighting of an unexplained flying object at Rendlesham in Suffolk in the 1980s.
The incident hit the headlines when American servicemen stationed at RAF Woodbridge reported mysterious lights above nearby Rendlesham Forest.
It's widely been regarded as Britain's most famous close encounter ever since.
Tonight, the mystery will be revisited as part of a new ITV programme with Ben Shepard and Julia Bradbury called 'Mystery Map'.
Together, they'll aim to get to the bottom of the the country's mysteries and unexplained flying objects, starting with the Rendlesham case.
However, Julia Bradbury believes that sometimes it's best for a mystery to remain unexplained:
Like many of the mysteries featured in the series, the fact that more than an element of doubt remains over who was telling the truth over what happened on that dark Christmas night in 1980 means that we still can't be 100% sure that we are alone in space.
And as a region of UFO believers, we wouldn't want it any other way.
Click below to watch a report from David Wood
You can watch 'Mystery Map' tonight on ITV, with the programme starting at 20:00.