noctilucent

Those look like noctilucent clouds in the north, or possibly more aurora.

Yeah, there seems to be a lot of noctilucent clouds this year.

So while I'm no expert on noctilucent cloud formation and happy to be given more info, the prima facia case seems to favor rocket launches seeding noctilucent clouds much more readily than volcanic eruptions.

I googled and found out that the highest clouds are the noctilucent clouds.

One of the perks of living at 60°N: noctilucent clouds are a fairly frequent phenomenon in the summer, moreso than northern lights in the winter in fact.

I had missed the noctilucent clouds and transit of Phobos.

Just to throw in some round figures: noctilucent clouds are formed between 80 and 85 km altitude [2] large volcanic eruption plumes top out somewhere between 31 and 45 km [3] Falcon 9 launches stage at 80 km [4], meaning 23% of their propellant mass [5] is converted to exhaust at that altitude or higher.

"Recent studies suggests that increased atmospheric methane emissions produce additional water vapor once the methane molecules reach the mesosphere - creating, or reinforcing existing noctilucent clouds.[1]"

FTA: "It’s not hard to see how a warming Earth could change those dynamics: as the globe heats up, the top of the atmosphere should get colder." But if that were the case, noctilucent clouds would normally be an equatorial -- not a polar -- phenomenon.

Noctilucent clouds are the only natural-occuring ice on the planet that isn't hexagonal, instead having mostly cubic crystals, which are stable in the low temp/low pressure environment.

Noctilucent clouds are not that uncommon in higher latitudes.

Noctilucent clouds, for example, can only be seen from latitudes of 45–80° both north and south, and they form around 75–85 kilometres above Earth’s surface, at the top of the mesosphere, the highest part of our atmosphere.