Brian Cox and Robin Ince host a close encounter of the first kind with comedian Lucy Beaumont, astronomer Maggie Aderin-Pocock, Prof Tim O’Brien and science presenter Dallas Cambell to ask if UFOs and aliens have visited Earth.

• Brian Cox
• Robin Ince
• Lucy Beaumont
• Maggie Aderin-Pocock
• Tim O'Brien
• Dallas Campbell
• Gill Adams
• Mike Covell