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A Quick Riff on New Horizons

We’re starting to get a better view of Ultima Thule, the next destination for the New Horizons spacecraft, which is due to make its flyby of the Kuiper Belt Object also known as 2014 MU69 on New Year’s Eve (0533 UTC January 1) The images below can’t help but recall the gradual approach to Pluto/Charon as New Horizons closed on what turned out to be a spectacularly successful encounter. Here’s hoping Ultima Thule is just as productive in teaching us something about Kuiper Belt Objects in general. Here’s hoping, too, for another KBO flyby down the road.

What we see in the dual images is the view (at the left) through LORRI (Long Range Reconnaissance Imager), averaging 10 individual 30-second exposures, with Ultima Thule just barely visible in the yellow circle. The component exposures were taken about a day before a course correction maneuver on December 2 and show Ultima visible against background stars. At the right is the image re-processed to remove the background starfield. Subtracting the star background has left artifacts in the image which should be disregarded.

Image: Ultima Thule as seen at 6.47 billion kilometers (4.01 billion miles) from the Sun and 3.87 million kilometers (2.4 million miles) from the New Horizons spacecraft. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

Thus New Horizons keeps giving us firsts, this time the furthest trajectory correction ever made enroute to the furthest flyby of any object in the Solar System ever attempted. The inherent ‘kick’ of space exploration is that sense of pushing ever deeper into a realm that has no boundaries. It’s the same sense I had when Huygens was descending on its parachute into the orange haze of Titan, the furthest landfall in human history. One of these days we’ll have landfalls beyond Titan, but for now, flybys are more than proving their worth.

Richard Feynman knew all about ‘kicks.’ On the matter of honors vs. accomplishment (he won the Nobel in 1965), he had this to say:

“I don’t see that it makes any point that someone in the Swedish academy just decides that this work is noble enough to receive a prize — I’ve already gotten the prize. The prize is the pleasure of finding a thing out, the kick in the discovery, the observation that other people use it — those are the real things. The honors are unreal to me. I don’t believe in honors.”

I do believe in honors, but I can agree with Feynman that they’re not what people work for. When someone asked me at a conference what drove me to write about space day after day, it was Feynman I quoted. Why else do we pursue passionate interests but for the ‘kick in the discovery?’ For me, learning new things brings the same exuberance I feel when listening to good jazz — Bill Evans or Miles Davis take me into imaginative flybys of realms that in a way parallel what we do with spacecraft and hard, physical objects. A Dexter Gordon solo opens up a sky’s worth of meditations and you don’t know how it will end.

But back to actual hardware. That trajectory correction New Horizons accomplished on Sunday tweaked the spacecraft’s course to keep it on schedule for arrival at Ultima Thule, a flyby at 3,500 kilometers (2,200 miles) that will take place at 0033 EST (0533 UTC) on Jan. 1. Three other course corrections are built into the game plan if it turns out they are needed. This one, taking place at 0855 EST (1355 UTC) on December 2, was tiny: A 105-second thruster burn that adjusted velocity by a little over 1 meter per second (2.2 miles per hour). We’re 26 days and 17 hours out from Ultima Thule as I write this, with mission elapsed time of 4,702 days.


Comments on this entry are closed.

  • Thomas R Mazanec December 5, 2018, 15:06

    When will we find out if there is to be another flyby?

    • Ivar Brouwer December 24, 2018, 16:56

      Hi Thomas – (no specialist at all, but..) the problem here is how to find an object to target, since there is none known that can be reached. (this was different when Pluto was reached with Hubble being allocated observation time)

      After the flyby of Ultima Thule, the resources need to be assessed.
      1- Then, if enough fuel (Fuel represents possible search angle) is available budget needs to be allocated. (same as for going to Ultima Thule, budget was settled later)
      2- Then an object needs to be found, is there a telescope that can find something in the narrow angle available? The deeper you can look, the further you might be able to find something: I presume Hubble probably falls short, or we would have seen something bigger further out when they found Ultima Thule. And Thus we would need to wait for James Webb to come online. (the longer that takes the more problematic it gets as the operating lifetime of New Horizons is of course finite, although I don’t know to what degree)

      Is there a ground based telescope (or combination) that can substitute for James Webb? If so, that would be advised as chances to find something dwindle by the minute once passed Ultima Thule, if possible I would have assumed they would have done this already, similar to what’s done before… So my best guess: we need to wait for James Webb.

      • Daniel Eig December 27, 2018, 16:49

        The imaging capabilities of the NH Lorri imager have improved to the point that the team has posted that they may try using that to find new targets of opportunity.

        In 2012 they posted max exposure time was 10 seconds at 4 arc seconds resolution – far worse than Earth based telescopes – and using fuel besides. So at that time it didn’t seem a useful excercise.

        In a recent 2018 paper they posted that they can now achieve 30 second observation times, tripling the sensitivity. They also suggested that the next flyby might be of a comet nucleus, if any are detected in its path:

        Another possibility is overwriting the flyby software with new imaging/detection software to reduce the amount of data that needs to be sent back to Earth:

  • Antonio December 5, 2018, 17:39

    How much level of detail will we be able to see from Ultima Thule? (say, meters per pixel, for example).

    • Karl Pestell December 6, 2018, 21:41

      The pixel sizes of the best expected color and gray scale images and infrared spectra will be 330 meters, 140 meters, and 1.8 kilometers respectively. There is a chance of higher resolution grayscale images, with 33 meter pixels, if the high-resolution LORRI camera is able to point accurately at Ultima, but the necessary accuracy isn’t guaranteed.


      • Antonio December 7, 2018, 13:50


      • J. Jason Wentworth December 8, 2018, 9:52

        Might a “tele-upgrade” of New Horizons enable it to obtain higher-resolution pictures than it was designed for (not of Ultima Thule, as there isn’t enough time now, but of any additional Kuiper Belt object(s) it might fly past in the future)? I’m thinking of the autonomous navigation capability, using the spacecraft camera, that Deep Space 1 demonstrated at Comet Borrely in 2001. Also:

        Such “tele-upgrades” are nothing new. Voyager 2’s on-board computer was reprogrammed, years after launch, so that its thrusters could be fired in very short bursts, which enabled it to take longer exposures of Uranus and Neptune and their rings and moons (many of which are quite dark), in the gloom of the outer Solar System. More recently, the Deep Impact “mother” spacecraft was also reprogrammed, facilitating its EPOXI follow-on comet flyby and exoplanet search missions.

        • Karl Pestell December 8, 2018, 20:47

          Good news, Alan Stern and his team have thought of this too:

          It is also possible that another flyby target can be found and reached with the remaining fuel supply. And after that? Another exciting possibility is that we can dramatically augment New Horizons’ capabilities by uploading new observing and onboard data reduction software once its flyby software is no longer needed. If NASA someday approves such a plan, New Horizons could survey the Kuiper Belt population in ways that no other mission or telescope on Earth or in Earth orbit can, and possibly even detect and hunt down its own next flyby target.

          Future New Horizons extended missions, if funded by NASA, could explore even farther out. The spacecraft is on an escape trajectory from the Sun, traveling about 3 Astronomical Units from the Sun per year. Moreover, New Horizons and its payload sensors are healthy and operating perfectly. The spacecraft has enough power and fuel to operate for 15-20 more years, perhaps enough to reach the boundary of interstellar space.


          What we need to do is keep checking their website to convince NASA there is enough interest to keep funding the mission!

  • Robin Datta December 5, 2018, 20:38

    With bated breath of anticipation is awaited the word from afar that more more words are to follow…

  • Scott Guerin December 6, 2018, 12:53

    Paul we all owe you a debt of gratitude for your knowledge, ability to communicate, and willingness to do the hard work day after day…

    Happy Holidays!

    • Paul Gilster December 6, 2018, 14:31

      Why thank you, Scott, and very best wishes for the holidays to you and yours! I hope we’ll get a chance to talk in person again soon.

  • ljk December 10, 2018, 9:53

    Beam Your Greeting to Ultima Thule as New Horizons Flies By On New Year’s 2019!

    Join the First Mission to Explore the Kuiper Belt!

    NASA’s New Horizons spacecraft is poised to conduct the farthest planetary flyby ever – an encounter with the Kuiper Belt object nicknamed “Ultima Thule” – on January 1, 2019. Choose a message for the mission team to beam (along with your name) to New Horizons as it speeds past Ultima four billion miles from home. Traveling at light speed, your message will reach the spacecraft about six hours after leaving the satellite communications facility at the Johns Hopkins Applied Physics Lab in Maryland.

    Submissions will be accepted through December 21, 2018.


    Of course those messages are not going to stop once they reach New Horizons. Not sure what that probe would do with them anyway.

  • ljk December 21, 2018, 12:00

    When human stupidity and bloated government bureaucracy get in the way of real science and historic moments:


  • ljk December 21, 2018, 13:47

    As Yogi Beara once supposedly said, it ain’t over til it’s over!


    To quote:

    The team will propose sending New Horizons “to explore even deeper in the Kuiper Belt, to use our telescopes onboard to study objects in ways you can’t from the Earth,” New Horizons principal investigator Alan Stern, of the Southwest Research Institute in Boulder, Colorado, said during a webcast mission update yesterday (Dec. 19). (The Kuiper Belt is the ring of icy bodies beyond Neptune; the belt includes Pluto, Ultima Thule and milions of other bodies.)

    “And we hope to hunt down one more KBO — one more Kuiper Belt object — and make an even more distant flyby in the 2020s,” Stern added.

    New Horizons, which launched in January 2006, has enough juice left in its nuclear battery (a radioisotope thermoelectric generator, or RTG) to keep the power on through the mid to late 2030s, he said.

    “And we’ve got fuel, and the spacecraft’s in great health,” Stern said. “So, I think there’s a bright future ahead.”

    Might as well since they are already out there. On the other hand this will delay the New Horizons Message Initiative, which further shows that they should have provided a proper information package for the space probe before it launched. Or at least a duplicate of the Pioneer Plaque or even the Voyager Record.


  • ljk December 21, 2018, 14:06

    Days Before Ultima Thule Flyby, New Horizons Has Detected Something Weird About Its Distant Target

    George Dvorsky

    December 21, 2018 at 10:50 a.m.

    NASA’s New Horizons is en route to Ultima Thule, a journey that will see the NASA spacecraft whiz past this mysterious Kuiper Belt object on New Year’s Day. But as the probe nears, mission specialists are already having to deal with a rather strange observation—an anomaly in the way Ultima Thule is reflecting incoming light.

    New Horizons will zoom past Ultima Thule at 12:33am ET on January 1, 2019, at speeds in excess of 31,500 miles per hour (50,700 kilometers per hour) and at a distance of around 2,200 miles (3,500 kilometers). We’ll be able to see the object in exquisite detail, but until then, project scientists are having to contend with an unexpected mystery. By analyzing the hundreds of photos taken of the object by New Horizons thus far, project scientists have been trying to measure its brightness— but they’ve failed to detect periodic changes in Ultima’s luminosity as it rotates.

    Full article here:


  • Michael December 29, 2018, 19:09

    Why is the flyby so far away? Couldn’t we get any closer than 2200 km?