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Ultima Thule at Highest Resolution

One of the most enjoyable interviews I’ve been involved with lately was with Ryan Ferris, who runs the podcast Cosmic Tortoise from Christchurch, New Zealand. Ryan’s questions were sharp and of a philosophic bent, plumbing issues like the purpose and direction of human exploration. From Thor Heyerdahl’s extraordinary experiments at shipbuilding and navigation to the impulses that took Polynesian sailors into unknown waters as they settled Pacific islands, is there an innate human impulse to explore? We kicked all this around, along with SETI, the ‘Oumuamua object, and the need for a re-orienting long-term approach to civilization.

Ultima Thule and the recent exploration of it by New Horizons fit comfortably within the narrative Ryan and I discussed, as an example of satisfying that drive to push into the unknown, and also as an early marker for the growth of infrastructure in the Solar System. The Kuiper Belt pushes us hard for now, but we learn with each mission. In the meantime, forays of growing complexity to the Moon and Mars, as well as nearby asteroids, will teach us many things about human and robotic operations in ways that can extend them more frequently to system’s edge.

I’m still jazzed about Ultima Thule. The New Horizons team is saying the recently released images have the highest resolution of any the spacecraft has taken during its mission. Note the surface detail including several bright areas, roughly circular, as well as dark pits near the terminator. We’ve got so much data yet to come as New Horizons continues to return its information, so there is much to figure out at this point. “Whether these features are craters produced by impactors, sublimation pits, collapse pits, or something entirely different, is being debated in our science team,” said John Spencer, deputy project scientist from SwRI.

Image: The most detailed images of Ultima Thule — obtained just minutes before the spacecraft’s closest approach at 12:33 a.m. EST on Jan. 1 — have a resolution of about 33 meters (110 feet) per pixel. Their combination of higher spatial resolution and a favorable viewing geometry offer an unprecedented opportunity to investigate the surface of Ultima Thule, believed to be the most primitive object ever encountered by a spacecraft. This processed, composite picture combines nine individual images taken with the Long Range Reconnaissance Imager (LORRI), each with an exposure time of 0.025 seconds, just 6 ½ minutes before the spacecraft’s closest approach to Ultima Thule (officially named 2014 MU69). The image was taken at 5:26 UT (12:26 a.m. EST) on Jan. 1, 2019, when the spacecraft was 6,628 kilometers (4,109 miles) from Ultima Thule and 6.6 billion kilometers (4.1 billion miles) from Earth. The angle between the spacecraft, Ultima Thule and the Sun – known as the “phase angle” – was 33 degrees. Credit: NASA/Johns Hopkins Applied Physics Laboratory/Southwest Research Institute, National Optical Astronomy Observatory

The success at Ultima Thule and the possibility of another KBO encounter in an extended mission will keep New Horizons in our thoughts for a long time to come — even after its KBO adventures have ended, we’ll still be tracking a live, outbound spacecraft just as we follow the Voyagers. The degree of precision exhibited in the Ultima Thule work is made possible by the stellar occultations we’ve discussed here in past months as well as data from the European Space Agency’s Gaia mission, so critical for star locations during the occultation campaigns.

Image: New Horizons scientists created this movie from 14 different images taken by the New Horizons Long Range Reconnaissance Imager (LORRI) shortly before the spacecraft flew past the Kuiper Belt object nicknamed Ultima Thule (officially named 2014 MU69) on Jan. 1, 2019. The central frame of this sequence was taken on Jan. 1 at 5:26:54 UT (12:26 a.m. EST), when New Horizons was 6,640 kilometers (4,117 miles) from Ultima Thule, some 6.6 billion kilometers (4.1 billion miles) from Earth. Ultima Thule nearly completely fills the LORRI image and is perfectly captured in the frames, an astounding technical feat given the uncertain location of Ultima Thule and the New Horizons spacecraft flying past it at over 14.3 kilometers per second. Credit: NASA/Johns Hopkins Applied Physics Laboratory/Southwest Research Institute.

Closing to within 3,500 kilometers of its target, the spacecraft moved three times closer to Ultima than when it flew past Pluto/Charon in July of 2015. No wonder Alan Stern is exultant:

“Getting these images required us to know precisely where both tiny Ultima and New Horizons were — moment by moment – as they passed one another at over 32,000 miles per hour in the dim light of the Kuiper Belt, a billion miles beyond Pluto. This was a much tougher observation than anything we had attempted in our 2015 Pluto flyby.

“These ‘stretch goal’ observations were risky, because there was a real chance we’d only get part or even none of Ultima in the camera’s narrow field of view,” he continued. “But the science, operations and navigation teams nailed it, and the result is a field day for our science team! Some of the details we now see on Ultima Thule’s surface are unlike any object ever explored before.”

The golden age of human discovery continues; indeed, it is just beginning. If you want to explore the raw imagery from the LORRI instrument, have a look at the New Horizons LORRI website. And give some thought to context. One thing we should recall as we ponder future exploration is a vast, island-dotted Pacific, and ancestors who navigated it by wind, currents and stars.


Comments on this entry are closed.

  • Michael Spencer February 26, 2019, 14:55

    How lucky we are that Ultima Thule isn’t another round rock. Ad nothing against round rocks! But until our sample size gets dramatically bigger there’s no way to know nothing about the range of shapes.

    I wonder if someone would explain something about how the last image was made?

    The huge relative velocity drives very short shutter speeds; that part is easy to understand. More difficult is this: Space is dark. Really, really dark.* That being the case, how are those very bright images obtained? I suppose the same principle/technique applies to images from Mars, and beyond?

    *With apologies to Mr. Adams

    • Charley February 26, 2019, 21:01

      Mr. Adams? who’s that ?

      • Paul Gilster February 27, 2019, 9:56

        Douglas Adams is the author of the Hitchhiker’s Guide to the Galaxy series. What Michael is referring to is his quote: “Space,” it says, “is big. Really big. You just won’t believe how vastly, hugely, mindbogglingly big it is. I mean, you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space.” This is also one of my favorite lines. Another: “There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened.”

        • ljk February 27, 2019, 11:32

          My favorite Douglas Adams quote is still this one from The Hitch-Hiker’s Guide to the Galaxy series, which started out on BBC Radio in 1978:

          “For instance, on the planet Earth, man had always assumed that he was more intelligent than dolphins because he had achieved so much—the wheel, New York, wars and so on—whilst all the dolphins had ever done was muck about in the water having a good time. But conversely, the dolphins had always believed that they were far more intelligent than man—for precisely the same reasons.”


          • Alex Tolley February 27, 2019, 14:22

            ….and there is the answer to the Fermi Question. ;)

            • ljk February 28, 2019, 10:48

              It certainly could be. Until the advent of electrical transmissions, it would have been very difficult for a distant observer to know there were intelligent beings on Earth. Even now our electromagnetic bubble is only about 200 light years across, in a galaxy of 400 billion star systems 100,000 light years wide.

              In all the time that humanity has existed, how many really bothered to consider the idea of intelligent extraterrestrial life? And of that number, how many made the effort to really search for it? And even further, how many attempted to communicate with it? All this from a society that supposedly is more ambitious and driven than the cetaceans. And with opposable thumbs at that.

        • Michael Spencer February 27, 2019, 12:59

          Paul: Thanks for cleaning up my hasty and clumsy question.

          The imaging system remains, at least to me, a stunning piece of technology, one that I want to understand more deeply. I suppose that the imaging system is state of the art, but physics still applies, and that’s what is driving my curiosity. How is such a stunning image even conceptualized, let alone created?

          Another commenter here (Andrei) characterizes ambient light at the surface of UT as comparable to moonlight (which can be variable, as we know). Dr. Stern, quoted in Yahoo News, describes the light level 4 billion miles from the sun (Ultima’s approximate orbit radius) as 1600 fainter than available on Earth; again a very wide margin. He has also said that the surface light level at Pluto was compare to the surface light level of Earth under clear skies and a full moon.

          I admit that my frame of reference is that of an amateur with ahigh end prosumer imaging device in mind, questioning aperture and shutter speed. Likely scientists have a different and more useful point of view.

          In the broadest, qualitative sense, I want to know: just how hard was it to get these images? Where does LORRI stand in the pantheon of similar devices? Given the “darkness” of UT, and given the very high relative velocities, and given the limitations, if any, of slewing the imager – how did these issues drive imager design and necessary compromises?

          –Michael Spencer

    • Andrei February 27, 2019, 5:39

      The camera were made to take images at Pluto comparable to moonlight on Earth. The image is then very much processed, look at the original images here:
      They suffer from compression and there’s a lot of lines.
      So I wonder if the image presented is stacked from several of the images of that page.
      Image processing might bring out a bit more detail, but not much.
      The closest image released is from 6549 km but the spacecraft closest point were about 3500 km, so there might be one image showing part of U-T surface being sent later – I did read they were supposed to take some such images. But am not entirely certain now when reading the commentary about the image we see above, as that is said to be the best image – that seem to be a contradiction.

  • Daniel February 26, 2019, 16:11

    While these are the highest resolution images captured, its not the end of the story. Thanks to modern (and still improving!) image processing techniques, even better images of Ultima Thule will be created. For example, by combining the captured images sub-pixel resolution should be achievable, bringing out even more details!

  • Charley February 26, 2019, 17:31

    My immediate reaction when I first saw the photographs from this asteroid was the amazement as to how much sunlight was present to illuminate the surface sufficiently to get clear pictures! I kind of thought that was amazing!
    My second reaction was that I found it totally natural that there existed the white banded neck region between the two main bodies, as for me personally I just made the assumption that this region was the result of innumerable amounts of corrosion at that particular juncture between a solid body. Yet there was a consensus that this was the joining point between two bodies that had gradually drifted into one another gravitationally and coalesced.
    For some reason or another, I don’t find this particularly an attractive viewpoint; would my view be possibly far more likely than two bodies who just gradually came into contact? Why would there be a particular white banded region that just happened to form ONLY at that particular juncture?

    • Harold Daughety February 27, 2019, 1:31

      Could the white neckband be glassy material from impact melting? And the white spots could be similar glassy material from impacts ?

      • Bruce D. Mayfield March 2, 2019, 17:32

        The white junction between the two parts looks to be the youngest terrain on UT. Melting is a reasonable surmise, but consider the shapes of the two halves before their merger. Currently the smaller part is said to resemble a walnut while the larger is pancake-like.

        What can account for these shapes and the brighter neck region? First, the pancake shaped Ultima gets that way due to rotation. Ultima and Thule are slowly orbiting each other in the same general plain as both bodies rotations. Their orbit is slow due to their low masses. Over time interactions with third bodies rob the system of momentum and the two objects become close enough that the high points on their equators begin to collide. These comparatively gentle collisions by faster spinning U with slower rotating T eventually carve an equatorial valley in T while progressively transferring rotational speed from U to T. The parts eventually match and lock together on a high point on T, but the parts rock about a bit, melting the junction before all motions between the two parts settle out and they freeze together permanently.

  • T. Pliska February 27, 2019, 0:57

    Just to add my totally uninformed speculation, is it possible the white ring visible in the center of Ultima is a ring left from where Thule was attached previously?

  • Michael Spencer February 27, 2019, 13:11

    Paul: I wanted to commend your appearance on the podcast “Cosmic Tortoise*” to other readers.

    Those of us interested in interstellar research are often seen through a lens that includes the loud, flashy voices of the ‘crazies’; our votes suffer, but sadly so too the subject.

    Rarely does a voice come forward supported by many years’ dispassionate discussion of current science. This is what makes your voice so important.

    I’d encourage you to expand your portfolio beyond this blog whenever opportunity presents.

    You know. In your space time…

    Michael Spencer


    • Paul Gilster February 27, 2019, 21:03

      Doing the Cosmic Tortoise interview was a pleasure because Ryan Ferris really does his homework on whatever topic he’s looking into at the time. Thanks for your thoughts on such opportunities, which I welcome.

  • ljk February 28, 2019, 11:05


    The Planet Nine Hypothesis

    Konstantin Batygin, Fred C. Adams, Michael E. Brown, Juliette C. Becker

    (Submitted on 26 Feb 2019)

    Over the course of the past two decades, observational surveys have unveiled the intricate orbital structure of the Kuiper Belt, a field of icy bodies orbiting the Sun beyond Neptune. In addition to a host of readily-predictable orbital behavior, the emerging census of trans-Neptunian objects displays dynamical phenomena that cannot be accounted for by interactions with the known eight-planet solar system alone.

    Specifically, explanations for the observed physical clustering of orbits with semi-major axes in excess of ∼250 AU, the detachment of perihelia of select Kuiper belt objects from Neptune, as well as the dynamical origin of highly inclined/retrograde long-period orbits remain elusive within the context of the classical view of the solar system.

    This newly outlined dynamical architecture of the distant solar system points to the existence of a new planet with mass of m 9 ∼5−10M ⊕ , residing on a moderately inclined orbit (i 9 ∼15−25° ) with semi-major axis a 9 ∼400−800 AU and eccentricity between e 9 ∼0.2−0.5 .

    This paper reviews the observational motivation, dynamical constraints, and prospects for detection of this proposed object known as Planet Nine.

    Comments: 92 pages, 28 figures, published in Physics Reports

    Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

    DOI: 10.1016/j.physrep.2019.01.009

    Cite as: arXiv:1902.10103 [astro-ph.EP]
    (or arXiv:1902.10103v1 [astro-ph.EP] for this version)

    Submission history

    From: Konstantin Batygin [view email]

    [v1] Tue, 26 Feb 2019 18:31:17 UTC (7,069 KB)


  • ljk February 28, 2019, 14:32


    Sharpest Ultima Thule

    Image Credit: NASA, Johns Hopkins University APL, Southwest Research Institute, National Optical Astronomy Observatory

    Explanation: On January 1, New Horizons swooped to within 3,500 kilometers of the Kuiper Belt world known as Ultima Thule. That’s about 3 times closer than its July 2015 closest approach to Pluto.

    The spacecraft’s unprecedented feat of navigational precision, supported by data from ground and space-based observing campaigns, was accomplished 6.6 billion kilometers (over 6 light-hours) from planet Earth. Six and a half minutes before closest approach to Ultima Thule it captured the nine frames used in this composite image.

    The most detailed picture possible of the farthest object ever explored, the image has a resolution of about 33 meters per pixel, revealing intriguing bright surface features and dark shadows near the terminator.

    A primitive Solar System object, Ultima Thule’s two lobes combine to span just 30 kilometers. The larger lobe, referred to as Ultima, is recently understood to be flattened like a fluffy pancake, while the smaller, Thule, has a shape that resembles a dented walnut.

  • ljk February 28, 2019, 15:23

    I think they need to start coming up with a more creative naming system, or at least one that will become less cumbersome:


  • ljk March 5, 2019, 11:35

    Planet 9 hypothesis gets a boost

    By Paul Scott Anderson in Space | March 3, 2019

    A large, unknown Planet 9 in our solar system continues to elude astronomers. But a new review article in Physics Reports explains why some scientists still think they’ll find it.


  • ljk March 5, 2019, 11:40


    New Horizons data indicates small Kuiper Belt Objects are rare

    by Laurel Kornfeld

    March 3, 2019

    The relatively small number of craters NASA’s New Horizons spacecraft found on Pluto’s largest moon Charon indicates very small objects are rare in the Kuiper Belt, according to a new study published in the journal Science.

    Craters on planets and moons are records of impacts by small bodies over long periods of time. These impactors are far too small to be seen from Earth, even by space telescopes. This is why data from New Horizons, which is now traveling through the doughnut-shaped region of icy objects beyond Neptune and Pluto, is so valuable in helping scientists better understand this distant region.

    Kelsi Singer of the Southwest Research Institute (SwRI) and New Horizons co-investigator, led a team of scientists who studied data from the spacecraft’s 2015 Pluto system flyby in an effort to determine whether small impactors ranging from 300 feet to one mile (91 meters to 1.6 kilometers) are common or rare in the Kuiper Belt.

    “These smaller Kuiper Belt Objects (KBOs) are much too small to really see with any telescopes from such a great distance,” Singer said in a press release. “New Horizons flying directly through the Kuiper Belt and collecting data there was key to learning about both large and small bodies of the Belt.”

    Because Pluto is geologically active, resurfacing has obscured its history of impacts. However, Charon, which is not geologically active, does present an impact history, and its surface has revealed far fewer impact craters than scientists expected prior to the flyby.

    Early results from this year’s Jan. 1 flyby of KBO Ultima Thule also reveals fewer craters than scientists expected to see on its surface.

    Asteroids and KBOs are objects left over from the solar system’s formation 4.6 billion years ago when the Sun and planets formed from a collapsing molecular cloud.

    “This surprising lack of small KBOs changes our view of the Kuiper Belt and shows that either its formation or evolution, or both, were somewhat different than those of the asteroid belt between Mars and Jupiter,” Singer said. “Perhaps the asteroid belt has more small bodies than the Kuiper Belt because its population experiences more collisions that break up larger objects into smaller ones.”

    Another goal of the New Horizons mission, in addition to studying the Pluto system and Ultima Thule up close, is to study the Kuiper Belt in situ and give scientists a better understanding of its makeup.

    “With the successful flyby of Ultima Thule early this year, we now have three distinct planetary surfaces to study,” Singer said. “This paper uses data from the Pluto-Charon flyby, which indicate fewer small impact craters than expected. And preliminary results from Ultima Thule support this finding.”

    New Horizons principal investigator Alan Stern, also of SwRI, described these findings as a significant breakthrough for scientists seeking insight into the nature of the Kuiper Belt.

    “Just as New Horizons revealed Pluto, its moons, and more recently, the KBO nicknamed Ultima Thule in exquisite detail, Dr. Singer’s team revealed key details about the population of KBOs at scales we cannot come close to directly seeing from Earth,” Stern said.

    Now past Ultima Thule, New Horizons continues to study and collect data on its Kuiper Belt environment. The spacecraft is expected to be operational into the 2030s and may visit a third target if one can be found along its path.

  • ljk May 20, 2019, 11:23

    Latest results of the Ultima Thule flyby with New Horizons in Science magazine online here: