Mr Max and Chris are back out for an evening walk in the Sun, rejoicing in the nearly once-in-a-lifetime view of the aurorae that much of the world enjoyed last week. We find out what causes the Northern and Southern lights, why last week was quite so good, and what the chances are of a similar show in the near future. We respect the lights, while being very good and Not Barking at things. There are loads of great aurora pictures in the Sky at Night Flickr group: https://www.flickr.com/groups/bbcskyatnight/?rb=1 Aurorawatch is here: https://aurorawatch.lancs.ac.uk/ and for those in the US there's the NOAA site here: https://www.swpc.noaa.gov/products/aurora-viewline-tonight-and-tomorrow-night-experimental A reminder that you can buy Chris' book here: https://www.amazon.co.uk/Our-Accidental-Universe-Discovery-Asteroids/dp/1911709186 (It's out in the US in June, so you'll have to be patient if you're there!)