Can we see the lunar landing sites with a telescope? Why is it cooler at altitude despite being closer to the Sun? Why is there no salt in sea ice? Was it windier when the Earth turned faster? What will end life on Earth sooner, the cooling core or the Sun becoming a red giant? Is modern medicine damaging the gene pool? How old is the average atom? This week David Rothery, Caroline Steel, Andrew Holding and Adam Townsend join Kat Arney to answering the science questions that you've been sending in...