Ok… this is not strictly UFOs, but it might interest you?
The BBC have an interesting sci-fi adventure by cult Writer, Piers Anthony , which you can listen to on Radio 7. It is called ‘ Ghost Galaxies ‘.
There are 2 episodes, the first one (is available to listen too for the next 4 days) and the second episode, is online for 5 more days.
Unfortunately, i’m not sure if you can listen to it from outside the UK?
The link can be found here .