Two Suns in the Sky?

Straight from the horse's mouth, or cow's stomach, this week how scientists have found the genetic clue to better biofuels; also, the brain basis of addiction, the cause of false-positive HIV tests, what causes the colours in a peacock's feathers, is Betelgeuse about to blow up, and what's neurofibromatosis? Join Dr Chris on this week's whistlestop tour of the scientific cosmos as he looks for the answers to life, the Universe and everything...