What is the meaning of the word "rare" in the context of astronomy? It seems to me calling the object discussed in the article "rare" is about as logical as saying the Earth is rare: of course a single object is rare.
dmix•2h ago
Well there's a few thousand trans-neptunian objects that have been discovered. I presume rare here is for the orbit pattern being perfectly in sync with Neptune itself.
adrian_b•2h ago
There already are known many trans-neptunian bodies whose movements are synchronized with Neptune. Pluto is also among those.
However all the others are closer to Neptune, therefore the ratios between their revolution periods an that of Neptune are relatively small rational numbers, while for this new object the ratio is 10, which is much greater.
So for now, it is one such object among many, so it may be called "rare", at least until others are discovered. In any case it was unexpected that resonances still exist at such distances.
dreamcompiler•3h ago
3-body problems are fun and there are still potentially a ton of resonances that have never been found, and that cannot be found analytically. This seems to be one of those.
TheHeasman•12m ago
"The survey was designed to search for bodies with orbits that extend far above and below the plane of the Earth's orbit around the sun, part of the outer solar system that hasn’t been well-studied."
Christ. I didn't realise we hadn't looked at stuff not in Earth's plane. That's a tonne of space to explore, right in our own backyard.
ghssds•4h ago
dmix•2h ago
adrian_b•2h ago
However all the others are closer to Neptune, therefore the ratios between their revolution periods an that of Neptune are relatively small rational numbers, while for this new object the ratio is 10, which is much greater.
So for now, it is one such object among many, so it may be called "rare", at least until others are discovered. In any case it was unexpected that resonances still exist at such distances.