Humans are running a dangerous experiment on our planet. We're putting more and more carbon dioxide and other gases into the atmosphere, which are trapping the sun's energy, and lo and behold, our planet is heating up in response. To fix this, we could cut carbon dioxide emissions, but that’s been hard. What if there were a shortcut? What if we could reflect some of the sun’s energy away before it had a chance to get trapped? Like… maybe with space mirrors?!