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.
Related Stories
2014 MU69, which New Horizons will fly by on January 1, 2019, appears to have an elongated shape or may be comprised of two objects:
Based on the occultation data, 2014 MU69 definitely appears to have an odd shape. In a press release, NASA officials said that it's either football shaped or a type of object called a contact binary. The size of MU69 or its components also can be determined from these data. It appears to be no more than 20 miles (30 km) long, or, if a binary, each about 9-12 miles (15-20 km) in diameter.
By comparison, Comet 67P/Churyumov–Gerasimenko consists of a large lobe measuring about 4.1 × 3.3 × 1.8 km and a small lobe of about 2.6 × 2.3 × 1.8 km.
New Horizons has taken images of the "Wishing Well" star cluster and the Kuiper belt objects 2012 HZ84 and 2012 HE85 using its LORRI instrument. New Horizons was over 6.12 billion kilometers (40.9 AU) away from Earth when it took the images (archive), beating the previous record by Voyager 1:
New Horizons was even farther from home than NASA's Voyager 1 when it captured the famous "Pale Blue Dot" image of Earth. That picture was part of a composite of 60 images looking back at the solar system, on Feb. 14, 1990, when Voyager was 3.75 billion miles (6.06 billion kilometers, or about 40.5 astronomical units [AU]) from Earth. Voyager 1's cameras were turned off shortly after that portrait, leaving its distance record unchallenged for more than 27 years.
[...] During its extended mission in the Kuiper Belt, which began in 2017, New Horizons is aiming to observe at least two-dozen other KBOs, dwarf planets and "Centaurs," former KBOs in unstable orbits that cross the orbits of the giant planets. Mission scientists study the images to determine the objects' shapes and surface properties, and to check for moons and rings. The spacecraft also is making nearly continuous measurements of the plasma, dust and neutral-gas environment along its path.
Previously: New Horizons Measures the Brightness of Galaxies Before Going Into Hibernation
New Horizons Target 2014 MU69 May be a "Contact Binary"
New Horizons Flyby Plan Finalized; Pluto Features Named
Tiny Moon Possibly Orbiting 2014 MU69
NASA's New Horizons team will again attempt observations of a stellar occultation of 2014 MU69, provisionally nicknamed Ultima Thule. Previous observations made when the object passed in front of a background star suggested that it was a contact binary and may have a small moon:
The goal is to learn as much as possible about 2014 MU69, nicknamed Ultima Thule, which New Horizons will zoom past on Jan. 1, 2019. "This occultation will give us hints about what to expect at Ultima Thule and help us refine our flyby plans," New Horizons occultation-event leader Marc Buie, of the Southwest Research Institute in Boulder, Colorado, said in a statement.
This is not the mission team's first shadow rodeo. Last summer, scientists traveled to Argentina and South Africa for occultation observations; the Argentina crew hit the jackpot, gathering data that helped set the planned flyby distance at 2,175 miles (3,500 kilometers).
[...] Ultima Thule lies about 1 billion miles (1.6 billion km) beyond Pluto, which New Horizons famously flew by in July 2015. Scientists think Ultima Thule is about 20 miles (32 km) across if it's a single object; if it's two bodies, each component is probably 9 miles to 12 miles (15 to 21 km) long.
An occultation was used to determine that the dwarf planet Haumea may have a ring system in addition to its two known moons.
(Score: 0) by Anonymous Coward on Thursday December 14 2017, @06:37AM (3 children)
If there's at least one moon, there may be many. That poses a danger to the probe because by the time it's close enough to photograph the area, it will be too late to change course. The probe is moving quite fast. Radio waves take about 6 hours to get there such that a round trip plus analysis time will only catch semi-larger moons in time.
I suppose they could add auto-detection-and-move software, but that's asking a lot for a probe so far away.
Or, they could fly further away, but then you don't get crisp info. Being this is a "bonus" part of the mission, they'll probably accept some risk.
(Score: 2) by Immerman on Thursday December 14 2017, @03:21PM (2 children)
If an object has gravity, it potentially has many "moons". Finding one, especially a relatively large one, probably actually reduces the number of other satellites you'd expect to find, since it will destabilize the orbits of anything it's not in orbital resonance with it. (If not collide with them outright, sweeping the area clean)
Plus, even relatively densely populated space is still ridiculously empty. A three-mile moon at a distance of 120 miles fills only 1/6,400th of the space within its orbit, you could have hundreds of such moons within that space and still have less than a 1/10th chance of hitting anything as you flew through.
(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.
(Score: 2) by GreatAuntAnesthesia on Thursday December 14 2017, @10:11AM (1 child)
"Moony McMoonFace" sadly absent from list of potential names.
(Score: 2) by takyon on Thursday December 14 2017, @04:18PM
https://soylentnews.org/article.pl?sid=17/11/08/2134252 [soylentnews.org]
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(Score: 2) by takyon on Friday December 15 2017, @04:04PM
http://www.spaceflightinsider.com/missions/solar-system/engine-burn-refines-new-horizons-journey-kbo-2014-mu69/ [spaceflightinsider.com]
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