Starship Asterisk*

Absolutely brilliant animation -- so much information packed into such an elegant presentation.

Not really "N-hemi-centric", beyond the universal convention that N is "up", but a version without the (distracting, barely legible) labels would be nice.

This reminds me that there seem to be a lot of tour operators who are promoting tours to northern (European) latitudes with claims along the lines of "NASA predicts the brightest northern lights display for 50 years this winter". Being pretty sceptical about such things, I've tried to find...

Turns out that it's really quite hard to determine the mass of/number of stars in our own galaxy very accurately, but even the range 10^11-10^12 solar masses is good enough to get a handle on the "grains of sand vs. numbers of stars" issue. I set this as an elementary question for an intro...