Why do Moths Fly Towards Light?

Sue Marchant

Chris Smith

Why are moths attracted to light?  How do red-leaved plants photosynthesise?  Why don't hayfever sufferers become tolerant to pollen? We take on these questions in this week's show as well as discover if our planet changes its weight, how our brains store information and whether the Sun has any gravity.  Plus, we discuss if man will ever land on Mars!