Astronomers May Have Spotted a Tiny Moon in The Outer Solar System

In the far reaches of the Solar System, past the orbit of Neptune, things start getting trickier and trickier to see.

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Tau.Neutrino said:

Astronomers May Have Spotted a Tiny Moon in The Outer Solar System

In the far reaches of the Solar System, past the orbit of Neptune, things start getting trickier and trickier to see.

more…

Oh, I see. So there have been two independent observations of (84522) 2002 TC302. The two disagree, so one possible solution to the discrepancy is that (84522) 2002 TC302 has a moon. ¿Is that the best you can do, a brighter albedo would have the same effect.

But I do like the observation using occultation. “Telescopes in Italy, France, Slovenia and Switzerland made 12 positive detections of the occultation event, as well as four negative detections.”

It’s not all that big. I count anything smaller than Ixion as fairly small.

By the way, the name Gonggong is new to me. It used to be called 2007 OR10. “Following the Kepler spacecraft’s large revision of Gonggong’s size in 2016”. The name was first announced on 5 February 2020. That makes it the 5th largest dwarf planet, including Pluto and Eris. By comparison, Ixion is the 27th and (84522) 2002 TC302 ranks about 60th.

That’s no moon

There’s a moon called Dactyl in orbit around the asteroid 243 Ida; Dactyl is about 1200×1600×1400m, and approximately spherical.

wookiemeister said:

That’s no moon

Hmm, you may or may not have a point there. The official term would be “natural satellite”. Would I be right in equating this to the common usage term “moon”?

A subtlety perhaps is that no comet has yet been observed to have a natural satellite

Natural satellites of trans-neptunian objects (TNOs) also officially count as TNOs in their own right. But moons of asteroids do not count as asteroids in their own right?