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Why is it called a standstill? A lot of words in that article and not much information. https://en.wikipedia.org/wiki/Lunar_standstill#Origin_of_name https://e
by kristianp 2y ago
Why is it called a standstill? A lot of words in that article and not much information.
https://en.wikipedia.org/wiki/Lunar_standstill#Origin_of_name https://en.wikipedia.org/wiki/Lunar_standstill#Origin_of_nam...
- kulahan 2y agotl;dr for the lazy (but I'm not very smart so don't trust me): the moon and earth orbit each other such that the moon cycles between rising high in the sky and low in the sky every ~2 weeks. Lunar Standstill is when our orbits align each other such that if you were to casually stargaze at the moon for a few nights in a row, it would seem to keep going to the same spot. Pretty cool imo, but I think you'd have to really be into the topic to appreciate it. It's pretty obscure knowledge!
- QuercusMax 2y agoSeems like you have to be a real moonhead to appreciate this event.
- hatthew 2y agoSo basically the moon's position follows a combination of several sine(ish) waves, and this is (close to) a global maxima of that combination? You and the article both say "high" which I would usually assume to mean "high altitude", but in this case it means "northerly azimuth"?
- vikingerik 2y agoYou're close, but it's not a few nights in a row, it's a few months in a row - the standstill is that it returns to the same angle above the horizon on each orbital pass (month), and thus to the same spot in the sky. (Night to night, the moon isn't in the same spot, because it's revolving along its ellipse to a different true anomaly position.)
- kulahan 2y agoThe event lasts months, but as I read, but if you compared the position over the course of more than a week, you’ll notice a difference in position. Sorry if I wasn’t clear!
- vikingerik 2y agoPossibly a better explanation than the sibling comment: The plane of the moon's orbit wobbles relative to the Earth's equator, with a period of 18.6 years. The "standstill" says that the moon apparently follows the same track from each orbital pass (month) to the next - it refers to the change in the moon's declination (angle above the horizon) at the same point in its orbit on successive months. At the time of a standstill, this change is at its minimum value, because the difference between the moon's orbital plane and earth's equator is momentarily at one extreme of the wobble (the peak or trough of a sinusoid.) "First in >18 years" is a clickbait headline - the interval is always that, there's nothing special about this one. It's as regular as saying "first full moon in 29.5 days".
- ysofunny 2y ago> It's as regular as saying "first full moon in 29.5 days". "the first sunrise in 24 hours!"