Title text:
I’ve had countless nights where the line never left the bottom zone of the graph, but the few moments where it’s climbed all the way to the top have made up for them all.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3196/
This is good to know. I’ve seen the aurora once and it was like the bottom of the graph describes it - a very faint glow, barely noticeable to the naked eye, but it turned up much better in photos.