A major mission that's underway: is a Chinese spacecraft heading back to Earth, carrying the first ever samples from the far side of the Moon. So, why are these samples so significant? And who will be able to study them? Guest: Dr Jonathan Webb, ABC Science Editor Brainteaser (answer in the audio): What could come next in this sequence: Canberra, Brussels, Beijing, Copenhagen, Cairo, ? For more of the latest science news, look for the science section on the ABC News website and sign up to a weekly email newsletter.