Have you read the news lately? You know that little tidbit about the dancing moons round my home planet, Neptune?
You haven’t? Really? Truly?
Oh dear, the important things in life, and you miss out…
Let me explain it you. Neptune 14 known moons – Naiad, Thalassa, Despina, Galatea, Larissa, Hippocamp, Proteus, Triton, Nereid, Halide, Sao, Laomedeia, Psamathe and Neso. Those in the list from Triton onwards are irregular moons, probably captured by Neptune.
Now the ‘dance of avoidance’ is supposedly going on between Naiad and Thalassa. Their orbits are 1,150 miles apart. Yes I do mean miles and not astronomical units or parsecs or lightyears. Miles is miles!
The dance ensures they stay 2,200 miles, since Naiad moves up and down every time it passes by Thalassa, which moves more slowly. Sitting on Thalassa, as I do when I want some peace and quiet from existence and the universe, Naiad’s movements take on a very strange, zigzagging dance. The moon would pass by twice from above, and then twice from below, repeating again and again and ad nauseum.
Got that? Good.
You humans call is orbital resonance, which you would expect to be fairly common.
What do you mean, why?
Well, when you have resonance you have stability and stability means it stays like that for a long long time. It’s this time that makes resonant orbits look more frequent that people who don’t-stop-to-think-through-the-subject think it’s happening in our neighbourhood too freaking often.
Right now we’ve got that sorted, I need to do some serious star gazing…
C.A.T. Blogdom 