Peter Kohler is the founder and director of The Plastic Tide, a charity made up of ocean, science and tech enthusiasts obsessed with working out ways to keep our beaches and seas clear of marine litter and plastics. This week, he's chatting to Dan about how plastic is affecting our oceans, what we can do to help and using drones. 

Plus Dangerous Dan is heading back 74,000 years to one of the most powerful volcanic eruptions ever, we're finding out how feeding birds in your garden may not be such a good idea and what happens if we spew in space!