Last year, 100 million tonnes of plastic were produced by industry. At the same time sufficient waste plastic was found floating in the world's oceans to make a string of bottles long enough to make it to the Moon. This week we find out what plastic is, how it is made, how to recycle it and why, in the future, it might literally grow on trees. Plus, reading Roman scrolls buried 2000 years by a volcano, how the magnetic history of a meteorite sheds light on the early Solar system, and an antidote to radiation...