Discover how the end of the dinosaurs was just one of five global extinction events that saw millions of species die – and how we can pull the planet back from the sixth mass extinction. Also this issue: meet the new Mars rover, how the human ear works, what makes food go bad, weird Aussie animals, hydrocar power, ghost towns, and much more. Plus, grab yourself three free How It Works Bookazine specials, digital posters and wallpapers worth over £30, for every reader.