1/10Dr Chris and Dr Xand learn about gravity.(R)
2/10Dr Chris and Dr Xand learn about meteorites and what happens when they land on Earth.(R)
3/10Dr Maggie discovers some clever coral that can tell the time.(R)
4/10Dr Chris and Dr Xand find out about the moon and how it affects our oceans and tides.(R)
5/10Dr Maggie fires lasers at the moon to measure just how far away it is.(R)
