This week, we're diving into the science of clean water, finding out why rivers and ponds are essential for wildlife, and how alien invaders are colonising our waterways. Plus, how a diet of glycerol makes yeast live longer, how microbes in mosquitoes can block malaria and how planting trees could reduce your electricity bills. We hear about the European Space Agency's Planck and Herschel missions to study the formation of galaxies and the fate of the universe, and in Kitchen Science, we explore the carbonated chemistry of fizzy water! Like this podcast? Please help us by supporting the Naked Scientists)