Saucer shape, Silver in colour, rotating coloured lights, silent.

It hovered, zipped to another area at incredible speed, stopped, then disappeared into the clouds

I am 58 years old now, but always remembered that sighting with a friend out walking to a wood. With hindsight and knowledge of G forces, I believe these objects may only be robotic probes, as anything clothed in flesh would be too fragile or short lived to withstand the immense forces imposed upon a body, which would be expensive to transport and might carry back some human infection, but the fact remains, if they're out there, so is the intelligence.