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New Horizons: The KBO Hunt Continues

Of the many interesting questions Nick Nielsen raised in last Friday’s post, the one that may be most familiar to the interstellar community is the question of potential breakthroughs. What happens if an unexpected discovery in propulsion makes all the intervening stages — building up a Solar System-wide infrastructure step by step — unnecessary? If we had the kind of disruptive breakthrough that enabled starflight tomorrow, wouldn’t the society that grew out of that capability be fundamentally different than one in which starflight took centuries to achieve?

I was mulling this over yesterday when I read Pluto-bound Probe Faces Crisis, a short article in Nature that several readers had passed along. With the New Horizons probe pressing on for a close-pass of Pluto/Charon next year, the assumption all along has been that it would make a course correction after the encounter to set up a flyby of a Kuiper Belt Object (KBO). The trick there is that the New Horizons team is running out of time to find the right KBO. The sense of urgency is revealed in the fact that mission scientists have asked for 160 orbits of observing time on the Hubble instrument, which the article calls a ‘rare request’ for an already operational mission.

Alexandra Witze sums up the reason for the delay in identifying a target in the Nature story:

In theory, project scientists should have identified a suitable KBO long ago. But they postponed their main search until 2011, waiting for all the possible KBO targets to begin converging on a narrow cone of space that New Horizons should be able to reach after its Pluto encounter. Starting to look for them before 2011 would have been impossible, says [mission co-investigator Will] Grundy, because they would have been spread over too much of the sky.


The Voyagers, Galileo, New Horizons and their ilk represent a familiar evolutionary model of our expansion into the outer Solar System as opposed to the kind of disruptive breakthrough Nick was speculating about. In this model, we learn from mission to mission, making each more capable, adding technologies that can get instruments to their destinations at a faster clip. We can’t predict disruptive technologies, but we can see a rational line of development of current tech as we tune up our deep space craft, one in which the ongoing New Horizons issues play a major role.

Image: Artist’s impression of the New Horizons spacecraft encountering a Kuiper Belt object. The Sun, more than 4.1 billion miles (6.7 billion kilometers) away, shines as a bright star embedded in the glow of the zodiacal dust cloud. Jupiter and Neptune are visible as orange and blue “stars” to the right of the Sun. Although you would not actually see the myriad other objects that make up the Kuiper Belt because they are so far apart, they are shown here to give the impression of an extensive disk of icy worlds beyond Neptune. Credit: Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute (JHUAPL/SwRI)

The next year is going to be filled with New Horizons news and, let’s hope, a resolution of the KBO issue. Fifty new KBOs have thus far been identified in the hunt, which has used the resources of the 8.2-metre Subaru Telescope in Hawaii and the 6.5-metre Magellan Telescopes in Chile. None, as it turns out, is close enough to New Horizons’ trajectory to make it feasible given the constraints on the spacecraft’s ability to maneuver. And as I’ve mentioned in these pages before, the search field is tricky, looking directly out along the plane of the galaxy, which means the faint signature of a KBO is readily lost in the starfield. The good news is that by adding Hubble into the mix — and a decision on this won’t be reached until June 13 — the chances of a detection soar over what they would be using ground-based telescopes alone.

Make no mistake, even a long-distance observation of a KBO from New Horizons’ 21-centimeter telescope would trump what we can see from Earth orbit, but obviously a much closer look at a primordial survivor from the Solar System’s early history would be preferable. We wait and hope for the best. Meanwhile, we in the interstellar community should be tracking this mission with great interest. New Horizons is pushing into terra incognita with instruments designed for the job, and represents, as Michael Michaud recently commented to me, a more relevant transition to our deep space future than the Voyager spacecraft. It should energize our designs for future craft that will push further into the Kuiper Belt and beyond. This incremental model works, and if along the way a disruptive breakthrough occurs, then so much the better.


Comments on this entry are closed.

  • ljk May 27, 2014, 10:17

    Paul Gilster says in the main article:

    “What happens if an unexpected discovery in propulsion makes all the intervening stages — building up a Solar System-wide infrastructure step by step — unnecessary? If we had the kind of disruptive breakthrough that enabled starflight tomorrow, wouldn’t the society that grew out of that capability be fundamentally different than one in which starflight took centuries to achieve?”

    Considering our current state of affairs, I cannot help but wonder in this regard what if the early European explorers of the New World had jet fighters, machine guns, and Agent Orange?

    If you watch the new Cosmos series, you might be forgiven to think that the Main Planetoid Belt and the Kuiper Belt are as dense with objects as that asteroid field in the second Star Wars film. Clearly the reality is otherwise.
    However, how long is New Horizons expected to keep functioning? Its interstellar forbearers, Pioneer 10 and 11 and Voyager 1 and 2, give us hope that it could last long enough to reach even a distant KBO.

    Wherever NH might end up in this big galaxy, don’t forget to add your one-word greeting to the probe here:


    Details here:



  • ljk May 27, 2014, 10:35

    Will we find signs of tectonics on Pluto? And what would that mean?

    Posted by Joseph O’Rourke

    2014/05/26 14:45 UTC

    It’s very cold in the outer solar system. Yet, studying the agglomerations of ice and rock far from the Sun is a smokin’ hot area of research. The newest kid on the block—2012 VP113, aka “Biden”—earned a lot of press because it, along with Sedna, another cosmic oddball, may have a story to tell about the very early history of our Solar System. But scientists haven’t forgotten Pluto, the O.D.P. (Original Dwarf Planet, hah).

    In preparation for the New Horizons spacecraft‘s flyby of Pluto in mid-2015, people want to clarify the implications of possible observations. Of course, speculating now means discussing ideas that will ultimately prove incorrect. The alternative, however, is waiting until after the mission’s completion to think about the scientific details. Pluto will have everyone’s attention during the flyby, but this interest, alack, will probably dissipate (unless New Horizons gets, like, eaten). Scientists should maximize their window of opportunity—prepared to present a scientifically correct story for Pluto’s evolution alongside all the “gee whiz” photos from the flyby.

    This paper, for instance, explains the scientific implications of pretty pictures of Pluto that show preserved features from ancient tectonic activity, like troughs, ridges, or bands. The authors conclude that such evidence would indicate that Pluto once hosted a global, subsurface ocean.

    Full article here:


  • William Blight May 27, 2014, 10:55

    I am still not convinced regarding the optimism about disruptive breakthroughs . I don’t see the resources or national energy directed toward fringe science. For example, NASA’s breakthrough propulsion program was shut down. Very few resources are being aimed at either Woodward (none) or White ( a small lab). Elon Musk has the best take on this. Put your own energy and talent into making us a two planet species – and don’t expect much from the government. The massive disruption of colonizing the solar system is the means for going interstellar. Probably, you will need enormous space infrastructure (solar and laser) to propel interstellar craft. Some investment in breakthrough propulsion is wise, but elaborating any plans on this propulsion is not.

  • James M. Essig May 27, 2014, 14:31

    I want NASA to find lots of KBO with lots of Uranium or Thorium in them.

    Anyone know of any credible studies on the possibility of Uranium and/or Thorium deposits in KBO.

    The reason I ask is that we already know how to do fission reactors. I can imagine nuclear fission powered space arks plying the depths of the Milky Way.

    No doubt, long duration life support would be a major hurdle to overcome as well as crew compatibility if cryogenic or hibernation states are not practical.

  • Geoffrey Hillend May 27, 2014, 18:56

    It’s pretty obvious what will happen with an unexpected discovery or breakthrough. It will make today’s technology completely obsolete or look like Junk. We will never built solar sail, etc if that happens.

    It still think that a space infrastructure is not needed for type three interstellar spacecraft. It’s easier and cheaper to build things on land and don’t see that changing in the near future. Designing might be different.

    What is that infrastructure? The development of efficient fusion reactors, and larger particle colliders to find the graviton( if the LHC is not high energy to see it)and develop a knowledge to manipulate the force of gravity which are all needed to have a high enough energy to power a warp drive and understand how to build it. A warp drive needs a gravity wave generating device to contract the space in front of it. We don’t know how to do that yet but it is on the distant future horizon.

  • Geoffrey Hillend May 27, 2014, 19:00

    In other words, we still don’t have the technological infrastructure, but we might in the future.

  • Astronist May 27, 2014, 19:23

    “What happens if an unexpected discovery in propulsion makes all the intervening stages — building up a Solar System-wide infrastructure step by step — unnecessary? If we had the kind of disruptive breakthrough that enabled starflight tomorrow, wouldn’t the society that grew out of that capability be fundamentally different than one in which starflight took centuries to achieve?”

    I disagree. What, after all, is the purpose of going to the stars? I would suggest that it is to spread our civilisation from one star to many, spreading our heritage across the Galaxy. But if we’re going to colonise planetary systems, then why not start with the one which is vastly more accessible than any other, namely our own?

    Building a solar-system-wide infrastructure is not a diversion from interstellar flight, it is in my view the main purpose of interstellar flight. And in order to do that, we should begin with our own Solar System. The unexpected propulsion breakthrough which you postulate would then see its first application in our local planetary system. It would both accelerate the development of our system, and use that process in order to build up the reliability necessary before it could be entrusted to longer-range missions.

    Stephen A.

  • David W May 27, 2014, 20:41

    Most of the Western Hemisphere population was wiped out by novel diseases what if that had been known?
    Anyway we need a revolution in our understanding of physics to get to these magic breakthroughs (see Star Trek First Contact as an example of magic breakthrough) While possible it isn’t probable
    I like the ideas from hear earlier this year of small probes accelerated from our existing power grid. It is a here and now idea that could also be used for asteroid defense Now that it looks like we are going to play cold war again maybe we could get some money for a new space idea

  • Glaas May 28, 2014, 5:17

    Will the Gaia space telescope be of help finding a KBO for New Horizons? It is starting to collect science data about now. In half a year it will have gathered parallaxes of (almost) the entire sky which would separate KBOs from background stars, if it is sensitive enough to register them at all.

    I think that cheap quick flybys like the NH should be given more consideration. The next Jupiter orbiter is planned for the 2030s, that’s so far into the future. Every flyby could pass by Jupiter for gravity assist and close to one of its moons, then to Uranus or Neptune (or centaur asteroid) and one of its moon. Then to a KBO and finally to the border of interstellar space. Two flybys a decade could be better than one orbiter every quarter of a century. The instruments would be a decade more modern upon arrival and designed to target the specific questions raised by the discoveries made by last flyby. Continuity would also have bonuses for risk management and for academic careers.

  • Sedjak May 29, 2014, 10:22

    Glaas, we can look to Kepler, too, if desperate enough, since it already is being proposed for a new mission, K2. It has decent enough optics to find big KBOs.

  • ljk June 5, 2014, 21:45

    Pluto Mission Leader Challenges Neil deGrasse Tyson to a Planet Debate


    There’s a year and a month to go before NASA’s New Horizons probe flies by Pluto, but that rendezvous is already one of the big events for Alan Stern, the scientist in charge of the $728 million mission.

    He’s also pressing for a debate with astrophysicist Neil deGrasse Tyson over Pluto’s planetary standing — and for something completely different, he’s even giving some thought to Father’s Day on June 15.

    Stern has so many projects in the air that he sometimes seems more like a juggler than a researcher. In addition to his roles as New Horizons’ principal investigator and a planetary scientist at the Southwest Research Institute in Boulder, Colorado, he helped create Uwingu, a commercial venture focusing on space education and research; the Golden Spike Company, which is planning private-sector moon missions; and the Suborbital Applications Research Group, which is helping researchers get ready for suborbital space studies.

    You can hear more about Stern’s juggling act at 8 p.m. ET Wednesday during an hourlong chat on “Virtually Speaking Science.”

    Full article here:


  • ljk June 6, 2014, 23:46


    Pluto and its moon snuggle under a shared atmosphere

    15:44 06 June 2014 by Ker Than

    Snuggle up, Pluto. The cold and distant dwarf planet may share a thin cloak with its largest moon.

    Simulations show that nitrogen from Pluto’s atmosphere could be flowing over to its moon Charon. If this is confirmed, Pluto and Charon would be the first known example of a planet and its moon sharing an atmosphere.

    Charon is almost half the size of Pluto and orbits much closer to the dwarf planet than our moon does to Earth. Studies in the 1980s suggested the two bodies might be able to exchange gases, but that work assumed Pluto’s atmosphere is made up primarily of methane, and that the gas was escaping at relatively high speeds.

    Using telescopes on Earth, astronomers took a closer look at the light coming from Pluto and scanned it for clues about the planet’s composition. It turns out that Pluto’s atmosphere consists mainly of nitrogen, a heavier gas than methane, and that the escape rate is lower. “People thought that even if Charon did gain an atmosphere through this process, it was too thin to ever detect,” says Robert Johnson at the University of Virginia in Charlottesville.

    Puffy atmosphere

    Now Johnson and his team have updated models of Pluto’s upper atmosphere, taking into account the way the nitrogen molecules would move and collide with each other. Their simulations show that the dwarf planet’s atmosphere could be warmer than thought, and so may be up to three times as thick as previously predicted.

    That means it may extend far enough into space for some gas to be pulled across by Charon’s gravity, giving it a tenuous covering. NASA’s New Horizons spacecraft is set to fly through the Pluto system in July 2015. It is carrying instruments that could detect any atmosphere that exists around Charon and figure out what it is made of, says mission leader Alan Stern at the Southwest Research Institute in Boulder, Colorado.

    Knowing the identities and concentrations of any gases around Charon will be essential for determining whether the moon’s atmosphere is borrowed from Pluto or created by some other means. It is also possible that gas from Charon’s interior is escaping through geysers or vents to create a thin atmosphere. And Stern’s latest study suggests that comet impacts on the moon’s surface could release clouds of gas to create a transient atmosphere.

    But if Pluto and Charon do share a shroud, the system could provide a real example of gas transfer between two bodies, helping us refine models of the phenomenon elsewhere in the galaxy.

    “It’s thought to happen all the time in astronomy, such as in the case of binary stars or exoplanets located close to their stars,” says Johnson. “Calculations and computer models are one thing. But here we have a spacecraft that’s going to fly by and directly test our simulations, which is quite exciting.”

    Journal references: Icarus, DOI: 10.1016/j.icarus.2014.05.002 and DOI: 10.1016/j.icarus.2014.03.008

  • ljk June 9, 2014, 8:50

    Do Pluto and Charon Share the Same Atmosphere?

    By Paul Scott Anderson

    Atmospheres are, of course, a common feature of planets and even some moons. Most of the planets in our solar system and a few moons have their own unique atmospheres, but now there may be evidence for something new – a shared atmosphere between a planet and moon, a situation never seen before.

    The dwarf planet Pluto is known to have a thin nitrogen atmosphere, and now new computer simulations suggest that it may be sharing that atmosphere with its largest moon, Charon. A very interesting finding if confirmed by the New Horizons probe due to reach Pluto in the summer of 2015.

    Back in the 1980s it was thought that the two bodies might be able to exchanges gases, since Charon, which is almost half the size of Pluto, orbits much closer than our Moon does to Earth. If Pluto’s atmosphere was mostly methane, as seemed reasonable, that might just work. It turned out, however, from later studies, that Pluto’s atmosphere is actually composed mostly of nitrogen, which would most likely be too heavy to escape from Pluto.

    So far, our best views of Pluto are still very fuzzy. New Horizons will give us our first clear close-up look at this intriguing world. Image Credit: NASA/JPL

    As Robert Johnson at the University of Virginia in Charlottesville, notes, “People thought that even if Charon did gain an atmosphere through this process, it was too thin to ever detect.”

    Full article here:


  • ljk June 10, 2014, 18:00

    ‘Something Wonderful!’: Preparing To Illuminate The Realms Of The Planetary Underworld – An Interview With Dr. Alan Stern

    By Leonidas Papadopoulos

    Pluto, magnanimous, whose realms profound
    Are fix’d beneath the firm and solid ground,
    In the Tartarian plains remote from fight,
    And wrapt forever in the depths of night.

    – Orphic Hymns, 6th century BC

    Renowned for his legendary ability to entrance and captivate gods and mortals alike with the beauty of his divine music, Orpheus was one of the celebrated heroes of Ancient Greek mythology who was able after a dangerous journey, to enter the Kingdom of Hades and face the god of the Underworld.

    In real life, following a multi-year journey through the Solar System, NASA’s New Horizons spacecraft enters the final leg of preparations for the start of its long-range reconnaissance of Pluto next January.

    Full article here:


  • ljk June 16, 2014, 13:37

    June 16, 2014

    RELEASE 14-167

    NASA Hubble to Begin Search Beyond Pluto for a New Horizons Mission Target

    After careful consideration and analysis, the Hubble Space Telescope Time Allocation Committee has recommended using Hubble to search for an object the Pluto-bound NASA New Horizons mission could visit after its flyby of Pluto in July 2015.

    “I am pleased that our science peer-review process arrived at a consensus as to how to effectively use Hubble’s unique capabilities to support the science goals of the New Horizons mission,” said Matt Mountain, director of the Space Telescope Science Institute (STScI) in Baltimore, Maryland.

    Fully carrying out the KBO search is contingent on the results from a pilot observation using Hubble data.

    The space telescope will scan an area of sky in the direction of the constellation Sagittarius to try and identify any objects orbiting within the Kuiper Belt. To discriminate between a foreground KBO and the clutter of background stars in Sagittarius, the telescope will turn at the predicted rate that KBOs are moving against the background stars. In the resulting images, the stars will be streaked, but any KBOs should appear as pinpoint objects.

    If the test observation identifies at least two KBOs of a specified brightness it will demonstrate statistically that Hubble has a chance of finding an appropriate KBO for New Horizons to visit. At that point, an additional allotment of observing time will continue the search across a field of view roughly the angular size of the full moon

    Full article here: