2014 MU69, which is still thought to be a contact binary or binary object, may also have a tiny moon (although additional observations are needed):
The object, known as 2014 MU69, is small, no more than 20 miles wide [30-40 km], but planetary scientists hope that it will turn out to be an ancient and pristine fragment from the earliest days of the solar system.
The moon, if it exists, might be about three miles [~5 km] wide, circling at a distance of about 120 miles [~190 km] from MU69, completing an orbit every two to four weeks, estimated Marc W. Buie, an astronomer at the Southwest Research Institute in Boulder, Colo.
He cautioned that the findings were tentative. "The story could change next week," he said.
Dr. Buie and others working on NASA's New Horizons mission provided an update on Tuesday at a meeting of the American Geophysical Union meeting here.
New Horizons is set to fly closer to 2014 MU69 than it did to Pluto (~3,500 km vs. 12,472 km). Flyby or collision course?
Voting for a possible new name for the object has been closed. Mjölnir (Thor's hammer) got the most votes. That name could fit the shape of 2014 MU69 somewhat.
Also at Sky & Telescope, Science News, and BBC.
(Score: 1, Informative) by Anonymous Coward on Thursday December 14 2017, @05:05PM (1 child)
Pluto has one large moon and 4 smaller ones.
It tends to push other moons into orbits having period resonance with it, correct. But that's not really the same as outright booting them away. Perhaps try to pass through the orbit of the main moon (when it's not in the area), since it's more likely to be cleaned up by the big moon. But, that may not be close enough for good observations of the main body.
(Score: 2) by Immerman on Friday December 15 2017, @04:04PM
That is quite true. My point was mainly that lesser orbital debris, unworthy of the name "moon", will tend to have their orbits rapidly destabilized. Whether they're nudged into a collision, ejection, or resonance where they'll be more likely to coalesce with other debris, the navigation hazards are much diminished.
I suspect you'll also tend to see far fewer out-of-plane satellites as well, as debris will be gradually tugged into alignment with the moon's orbit. Meaning that any flyby that avoids the moon's orbital plane is going to see far less debris than you would otherwise expect.