Walkabout The Galaxy

The second most energetic cosmic ray (really a particle) ever observed smashed into the Earth a couple of years ago, raising more questions about the origins of these incredibly energetic particles. Solar wind particles meanwhile smash into the planets, and now a green glow from Mars' atmosphere has been observed by one of the many spacecraft exploring the red planet. We also discuss a surprising exoplanet discovery, moon trivia, space news and more.