In science news, a new study has discovered that reindeers can sleep while they're eating. So, how on earth did scientists figure this out?

Two and a half months ago, a small sample of dust and rock from an asteroid was dropped into the desert in Utah by a NASA spacecraft. Scientists have been busy trying to analyse the sample since then - so what have they found?

Guest: Dr Jonathan Webb, ABC Science Editor

BRAINTEASER:

You've lost your bearings on the road between Truthtown, whose citizens never lie, and Liarsville, whose citizens always lie.A citizen from one of the towns is walking past. What single question should you ask them, to find out which way is which?