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A KBO Target for New Horizons

What we’ll eventually want is a good name. 2014 MU69 is the current designation for the Kuiper Belt Object now selected as the next destination for New Horizons, one of two identified as possibilities, and the one the New Horizons team itself recommended. Thus we have a target — a billion and a half kilometers beyond Pluto/Charon — for the much anticipated extended mission, but whether that mission will actually occur depends upon NASA review processes that are not yet complete. Still, the logic of putting the spacecraft to future use is hard to miss, as John Grunsfeld, chief of the agency’s Science Mission Directorate, is the first to note:

“Even as the New Horizon’s spacecraft speeds away from Pluto out into the Kuiper Belt, and the data from the exciting encounter with this new world is being streamed back to Earth, we are looking outward to the next destination for this intrepid explorer. While discussions whether to approve this extended mission will take place in the larger context of the planetary science portfolio, we expect it to be much less expensive than the prime mission while still providing new and exciting science.”


Image: Path of NASA’s New Horizons spacecraft toward its next potential target, the Kuiper Belt object 2014 MU69, nicknamed “PT1” (for “Potential Target 1”) by the New Horizons team. Although NASA has selected 2014 MU69 as the target, as part of its normal review process the agency will conduct a detailed assessment before officially approving the mission extension to conduct additional science. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Alex Parker.

We wind up with a situation where action precedes future decision. While the extended mission proposal will not be turned in to NASA until next year, the spacecraft can’t delay its preparations for a rendezvous with 2014 MU69 — trajectory changes factor into the equation. New Horizons, as this JHU/APL news release points out, will perform four maneuvers in late October and early November to make the necessary course changes for a January 1, 2019 flyby.

In anticipation of probable work beyond Pluto/Charon, New Horizons has the necessary hydrazine for a KBO intercept, and we’ll be able to monitor its communications and data return for years to come. Researchers had their eye on the kind of primitive object out of which dwarf planets like Pluto themselves may have been made, and the new target fits the bill.

“2014 MU69 is a great choice because it is just the kind of ancient KBO, formed where it orbits now, that the Decadal Survey desired us to fly by,” said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute (SwRI) in Boulder, Colorado. “Moreover, this KBO costs less fuel to reach [than other candidate targets], leaving more fuel for the flyby, for ancillary science, and greater fuel reserves to protect against the unforeseen.”

As to that new name, 2014 MU69 is already being called PT1, for ‘potential target 1,’ but will want something a bit more muscular, and certainly more poetic. You’ll recall how tricky it was to find a KBO for this encounter in the first place (see, for example, New Horizons: Potential KBO Targets Identified). Among those found after the search began in 2011, none were within range of the craft’s fuel supply. It took the Hubble Space Telescope to discover, in the summer of 2014, the two prime candidates. And it’s easy to understand Alan Stern’s enthusiasm. 2014 MU69. at about 45 kilometers across, is ten times times bigger than the average comet and a thousand times more massive, even if it’s about 1/10,000th the mass of Pluto.

It wasn’t that long ago — in August of 1992, to be specific — that David Jewitt and Jane Luu discovered the first trans-Neptunian object beyond Pluto/Charon, one that gave rise to the term ‘cubewano,’ named after the latter part of its designation, (15760) 1992 QB1. Jewitt and Luu liked the name ‘Smiley’ for the KBO, but there is already an asteroid with that name (1613 Smiley), so like 2014 MU69, even the first identified KBO could use a new monicker. Whatever we call it, 2014 MU69 should give us a look at the early days of Solar System formation some 4.6 billion years ago, preserved by distance and the outer system deep freeze.


Comments on this entry are closed.

  • Andrew LePage August 31, 2015, 9:52

    Choosing a post-Pluto encounter target for New Horizons certainly proved to be a longer than expected ordeal! Thankfully, a suitable target has been found with an encounter date on my 57th birthday, no less (what a great gift that will be!). Hopefully, this will be just the first of many KBO encounters to come. With this in mind, perhaps it is time to start considering a follow on mission to Pluto (maybe as part of a larger project to reach Uranus and Neptune for the first time in a half a century as well as other targets beyond) with subsequent flybys of KBOs in the 2040s.


  • Alex Tolley August 31, 2015, 11:09

    Something to look forward to in 2019. Should we be placing bets on what we expect it will look like?

  • I Brouwer August 31, 2015, 16:38

    The follow up mission to 2014 MU69 will happen as it`s just too much a waste of money not to. And there`s hoping for some extra`s beyond that considering the cautious use of propellant. There`s also thinking that New horizons will measure the heliopause in more detail then Voyager did, if it has the tools.

    As for a Follow up mission to Pluto: unless they can do a lander or orbiter I would say going to Pluto again would make little sense as we already have the snapshot. Going to Neptune/Triton makes more sense and it will be so much easier to achieve orbit and do the `Cassini-manoeuvre` there. Also Neptune and Uranus are due some scientific attention, Triton has a lot going for it with something of an atmosphere and maybe an internal sea and active geology.

    Another Kuiperbelt visit will be cool but i would only grant it if you can create a trajectory that would string a multitude of these objects in one mission, like the voyagers had all the major planets in their flightpath. That would be interesting, due to their distances not very likely.

  • Charlie August 31, 2015, 18:01

    I really like the name 2014 MU6. To me it’s just a good name as any and why shouldn’t the body have a irregular name rather than something from a Roman or Greek mythology? I think is quite appropriate and sounds kind of nifty too.

  • Charlie August 31, 2015, 18:01

    Oh I forgot to add, is there any plans at all to allow for another body beyond the one they are anticipating or will the fuel be exhausted at this point?

  • Carl Keller August 31, 2015, 19:47

    Belt Object 2014 MU69 might be named Niflheim. If it belongs to another body, then other names should be forwarded.

    Niflheim is from the Elder and Younger Eddas. The lore of the beginning was in song, preserved in the Old Norse. There was Ginnungagap, the “grinning void”, in which there was a region of great heat, Muspel, and one of great cold, Niflheim. Their interaction produced mists. From this, it was sung, came all that follows in our phenomenal universe.

  • Michael September 1, 2015, 5:21

    As we get further from the Sun there is going to be less and less light but it should still be enough to see by.

  • Joy September 2, 2015, 4:00


    The Webb telescope has been delayed so many times that the current launch date has to be taken with a huge block of salt. But, the Webb is now supposed to launch Oct 2018, which would be before the 2014 MU69 encounter. The fuel should not be exhausted post encounter – the target was chosen for the fuel safety margin. If there are any more distant KBOs within the very narrow cone that New Horizons could maneuver in, the Webb could spot them. Other than Webb, we wouldn’t have the ability to detect any fainter targets.

  • ljk September 9, 2015, 8:46

    New Horizons has gone to Pluto, and now comes the Great Beyond

    The big encounter with Pluto is over. The void is dead ahead.

    NASA’s New Horizons spacecraft is hurtling through the Kuiper Belt, a cold, dark realm of tiny, icy objects and the occasional dwarf planet such as Pluto. The spacecraft’s science instruments are detecting plasma and dust, but its cameras have been turned off. For the moment, there’s nothing to see and not much to do other than measure the loneliness of deep space.

    New Horizons has a bit of an existential, or perhaps astronomical, dilemma: After you pass Pluto, there’s a whole lot of nothing.

    The spacecraft can maneuver slightly, but whatever it is going to look at next has to be more or less directly straight ahead. A couple of weeks ago, the New Horizons team decided to aim the spacecraft at a small object, roughly 28 miles in diameter and known as 2014 MU69. The spacecraft will fly past it on Jan. 1, 2019.

    Full article here:


    To quote:

    New Horizons still has to surmount a bureaucratic obstacle. NASA hasn’t yet approved an “extended mission” for the spacecraft. The New Horizons team has until spring to put together a proposal that lays out what an extended mission would cost. NASA would consult with the broader science community before signing off on the extension.

    In some respects, it seems like an easy decision: New Horizons is a healthy spacecraft. It passed through the Pluto system without any nasty collisions with damaging particles, and it has a radioactive power source that can keep it operational for a couple of decades at least. It has half a tank of propellant.

    “We don’t have to buy any rocket, we don’t have to fly across 3 billion miles of space, we don’t have to build a spacecraft,” said the team leader, planetary scientist Alan Stern.

    After Pluto, a spacecraft learns what space is really like: big and mostly empty.

    Mike Brown, the California Institute of Technology astronomer who has discovered a number of dwarf planets in the outer solar system, has to admit that it’s a rarefied realm: “Each one of them is further away from the next cool thing than the Earth is from Jupiter. It is a vast, almost completely empty region.”

  • ljk September 11, 2015, 14:02
  • Alex Tolley September 11, 2015, 14:27

    Solar power only works out to Jupiter:

    That needs to be qualified. What they mean is that using current arrays that the mass cost gets too high compared to nuclear power sources. Thin film solar, concentrators, etc can greatly extend the range of solar power. O’Neill postulated using solar power to create earth-like conditions in his habitats out to 2.7 light days, assuming the mirrors massed mo more than the habitat itself.