Sometimes, Earth mimics a supernova, producing a Terrestrial Gamma-ray Flash from the tops of thunderstorms. A new lightning sensor on the International Space Station could solve the mystery of these energetic bursts. [3:53]

Astronauts on the ISS are experimenting with a form of water that has a strange property: it can help start a fire. This fundamental physics investigation could have down-to-Earth benefits such as clean-burning municipal waste disposal...