> MTG-S1 is the first geostationary meteorological sounder satellite to fly over Europe
I was confused for a minute on how it's both _geostationary_ and _over Europe_ -- you can't be geostationary if your orbit is not over the equator!
Turns out[1] the MTG-S1 satellite is in fact geostationary and parked at exactly 0°00'00"N 0°00'00"E (off the coast of Ghana), 42164 km up from the center of Earth, it's just pointing at Europe at an angle.
NOAA/NASA (USA), EUMETSAT (European organization), JMA (Japan), KMA (Korea), and CMA (China) all have a geostationary satellite (one or more actually). So, northern hemisphere countries, but the coverage is global thanks to the fact that you need to be, as you say, above the equator.
I am surprised they would pick 0 for the latitude, it seems that most of Europe, whether it's the land or the people is east of that. Maybe some important weather systems develop over the Atlantic and they want to track that?
I had doubts about the "parked at exactly 0°00'00"N 0°00'00"E", thinking it was over Null Island just because the data wasn't updated yet and it was showing uninitialized values.
But you are right, [1] confirms "0° longitude".
[1] https://user.eumetsat.int/resources/user-guides/mtg-in-opera...