Are we alone?
It's a question a lot of us ponder when we look up to the sky and consider the vast amount of space beyond it.
But aliens might just be that bit closer than most of us think.
There have been countless reports of strange things in the sky believed to be alien aircraft. Just look on YouTube and you're bound to come across plenty of UFOs (unidentified flying objects) caught on camera.
But as real as it is for some, there are just as many people out there who will say "it's fake" or that there is a reasonable explanation for what has been observed.
The Ministry of Defence has published lists
link source - Leicester Mercury