NASA New Horizons Will Flyby a 30 km Object that is 4 Billion Miles Away

In 2014 the New Horizons team found an object that is now called Ultima Thule. It is located in the Kuiper belt in the outermost regions of the Solar System, beyond the orbit of Neptune. On January 1, 2019, New Horizons will flyby Ultima Thule at a distance of 3500 km (2200 miles). It will be at a distance of almost 6.5 billion km (4 billion miles) from the Sun, making this the most distant planetary flyby that has yet been attempted, and the first time that a Solar System object of this type has been seen close-up.

Ultima Thule measures approximately 30 kilometers in diameter and is irregularly shaped. In July 2017, Ultima Thule passed in front of a star as seen from Earth (a stellar occultation), allowing astronomers to determine that its shape is most likely a contact binary (two bodies that are touching) or a close binary system (two objects that are orbiting each other).

The lighting environment at its surface is very dim, as it receives only about 0.05% of the light from the Sun that Earth does. We do know that Ultima Thule has a reddish color, probably caused by exposure of hydrocarbons to sunlight over billions of years. The flyby will also reveal whether it has any moons, or even a ring system. Ultima Thule belongs to a class of Kuiper belt objects called the “cold classicals”, which have nearly circular orbits with low inclinations to the solar plane, and which have not been perturbed since their formation perhaps 4.6 billion years ago. Ultima Thule will therefore be the most primitive planetary object yet explored, and will reveal to us what conditions were like in this distant part of the Solar System as it condensed from the solar nebula.

28 thoughts on “NASA New Horizons Will Flyby a 30 km Object that is 4 Billion Miles Away”

  1. Going in such small steps will take a very long time. Lets say a thousand step of a generation each and that’s 60,000 years. Even 10 years get you about 10,000 years. Travelling between 0.1% to 1% the speed of light.

  2. We need to remember that Pluto is not just ¹⁄₈₀₀₀th the mass of Neptune, but its also ⅐ the mass of our own Moon. Making it really, really tiny. It does however seem to have had enough mass that it came into hydrostatic equilibrium. (ie, it is mostly a self-rounded sphere). The only reason as I remember that it didn’t get full planet status was because of those very same Plutinos. It hasn’t the mass (or really just the time) to clear its orbit of other contenders. Indeed … there seems to be a surprisingly high likelihood in the next few billion years that it’ll be impacted by either a Plutino, or more likely, a TNO or TKO. (Trans-neptunian object, or trans-kuiperian object). 

    It’d be quite a smash up. 
    That without telescopes, no one would notice. 

    Just saying,

  3. Yes, then there is parallax. 

    ²⁄₁₅₀₀ (AU/AU) radians, which is 
    360 × 60 ( ²⁄₁₅₀₀ ÷ 2π )
    9.16 arcmin… 

    (Hmmm… twice your 4.6? I must be forgetting something)

    But again, you’re right. The annual parallax motion would pretty much swamp the orbital drift motion. Make it pretty easy to identify as a planetoid. Provided you’re looking in the right spot, and get enough photons entering in a sufficiently large telescope, unremarkably free from aberrations and atmospheric wiggle. 

    Lots of ifs. 

    Just saying,

  4. In 2016 the global carbonated soft drinks market was worth just under $400 billion dollars. Coca Cola alone had revenues of ~$35 billion dollars.

    A soda pop drink, based on a formulation derived from the residuals found inside that alien dross, would storm the markets, and that $10 billion dollar investment of which you speak would be seen as one of the best investments in food industry history.

    “Bug Juice”?

  5. That’s not the point in that strategy. The point is to “hop” to the nearest star system, vs sending a ship directly like the European colonization method.

  6. Parallax. The Earth moves by 2 AU over 6 months. Even at 1500 AU, a planet would clearly describe a visible ellipse in the sky as we move, with a long axis of 4.6 arc-minutes. Stars have parallaxes measured in fractions of an arc-second.

  7. > Resonances.  Its all about various integer ratios.

    Correct. I describe Pluto as “Neptune’s gravitational b*tch” because it is locked into a 3:2 resonance orbit with it. Neptune does 3 orbits for every two that Pluto does. There are a bunch more “Plutinos” that behave this way, but Pluto is the largest. Coupled with Neptune being 8000 times more massive, I don’t see why people insist it is a major planet, aside from what they learned in grade school.

  8. The real problem remains… 1/d⁴ relationship between orb brightness and its distance from us. 1/d² is its solar illumination, and 1/d² is its reflected light diminution. then a far flung massive planet (about Neptune’s mass), with a gas giant albedo and so on, at 1,500 AU aphelion, would have an at-earth luminous flux of about 9 photons per second per m² of telescope aperture.  

    Not much, but certainly detectable. About 10× the brightness of the Ultima Thule object, absolute.  

    Thing is, at aphelion, it’d be traversing the sky at only 3.4×10⁻¹² radian/sec or 0.062 arcsec per day. VERY slow. Might be able to see it move against the so-called fixed stars over period of years. 22 arcsec a year.  

    Then the thing would be to determine that “it” was indeed a planet, and not a weird background star with a particularly large tangential velocity. That’d take some time, it would. 


  9. Right you are (re: distances, objects, counts).

    Turns out that Ultima Thule is only about 44 AU from Sol. Perihelion of what, 42, and aphelion of 46? Something like that.  Those parameters place it only modestly past Pluto, actually.  

    1 AU = Earth
    1.5 AU = Mars
    5.1 AU = Jup
    10 AU = Saturn
    20 AU = Uranus
    30 AU = Neptune
    40 AU = Pluto  (kind of … elongated orbit)

    So 44 AU, while substantially farther than 40 AU, is still more or less in Pluto’s eventual “sphere of gravitational influence”. Objects moving as slowly as the outer planets — especially relative to each other — would have a substantial amount of accumulated gravitational influence over time. Well … Pluto on Ultima Thule, and not vice versa.  

    Its all about various integer ratios.

    Just saying,

  10. We do… but with a subtle ‘problem’ in utilizing those asteroid belt and trans-trojans. Namely, both surface gravity and escape velocity. Now maybe “everything is resolveable as an engineering problem”, but I kind of think not.  

    If, say, you and I as the Mark and Goat prospecting team, were to hop in our nanofusion powered interplanetary flitter, and to head toward one of the more minor Earth-observable Asteroid Belt objects, and orbit it, and if it were to have a reasonably juicy diameter (say 50 km, somewhat bigger than Ultimate Thule), density of 1.5 kg/L, then it would have a surface gravity of only 0.010 m/s². About 0.1% of one earth gravity. Not very much. 

    Putting that in perspective, the escape velocity of Earth is over 11,000 m/s. The escape velocity of our asteroid would be 16 m/s, or about 36 miles per hour. Not much. We certainly could use a golf club to knock a rock off, never to return. IF we could even stand.  

    Jumping on earth is a 0.25 second-to-top maneuver, getting one about 0.3 m off ground. The same spring-loaded legs would shoot you up for well over 4 minutes, to a height of 285 meters. Even the little bumps and burbles of walking would be impossible. Hopping, perhaps.  Amusing.

    Just saying,

  11. Ultima Thule is about 25 × 40 km, according to the stellar occultation measurements made in South America a few months back. At 44 AU, the sunlight at UT is about 0.74 W/m², or 57× that of full-moonlight here. 

    Given an albedo estimated at 20%, a telescope here at Earth would be able to gather about 1 photon per square meter of scope, per second. Not very much, but certainly within present day astronometry. Indeed, the Hubble “discovery” images (gif file) have counts of about 500 photons coming from UT, with integration times just over 700 seconds per frame. 

    Astrometry measures at great precision, in order to infer other data about objects.

    In the case of stellar occultation, when the occulted star is far enough away (which of course is relative to the distant occulting object’s baseline), it can be treated as a point source. Then, down here on Planet Dirt, by spacing several telescopes a few tens-of-kilometers apart, along a line-of-interception, the occulting shadow will give an indication of the outline of the object iself.  

    This was done, and it was determined that UT is an elongated object, consistent with either a gravitationally bound pair of asteroids or a single long-ish one. In the Kuiper belt in particular, there is evidence that a fairly high number of objects are contact binaries, trinaries and even higher order agglomerations.  

    Thus, the albedo of UT has been bracketed at between 13% and 27% for broad spectrum sunlight.  


  12. The $10 billion dollar race ends with ownership of an alien hollow aluminium container which contains remnants of an aqueous solution of sucrose, fructose, caffeine and dissolved CO2 with trace artificial colours and flavours.

  13. I like that… “diffuse away”.  Kind of says it all, in a nutshell. We won’t really be jetting away at high speed … colonization wise … because insofar as I can yet tell, there ain’t no magic thrusters or compact gigawatt power systems capable of delivering more than a handful of micronewtons to any “colony sized” space vessel. 

    So yah. Diffuse. 

    Of note — all relatively near (!!!) Kuiper objects’ colonists would need substantial nuclear power for their outposts. Not only are the flying ice bergs dâhmned cold, they’re also not very well lit. At 40 AU (approximately Ultima Thule’s aphelion) it is lit up by approximately ¹⁄₁₆₀₀ the insolation we get here at Earth. Or, about 1 watt per square meter.  
    Roughly 57× brighter than the brightest moonlight we receive (full moon, directly overhead) on earth.

    So yah. Nuclear.

  14. Me! Me! I do!

    Let’s say that, at fly-by, a large, silvery sphere is seen to be partially exposed at the surface of one of the main masses. There would be a mad rush to be the first to make a “hands-on” claim to all the weird alien shtuff.

    Who would win that race?

    Who would build and launch the first craft to reach the artefact? What best-fastest tech would let what country/corporation become the “New Gods”?

    I’d put my money on Mr. Musk, with the kicking in of funds and tech from Bezos and Bigalow. Although, Russia could slap together a thermal-nuclear drive and out race anything “not-nuclear” Musk can get up in a hurry.

  15. Planet Nine is already being hunted for. But observing time on big ground telescopes is limited and fiercely fought over. Once the Large Synoptic Survey Telescope is finished, the chances of finding it go way up. It is specifically designed to find things that change or move in the sky, has a 8 meter mirror, and a 3600 megapixel camera. It will be up and running in a few years.

  16. > It is located in the Kuiper belt in the outermost regions of the Solar System

    Ultima Thule (2014 MU69) is nowhere near the edge of the Solar System. 2014 VP113 never comes closer than twice as far as Thule, the dwarf planet Sedna has an orbit which reaches 20 times farther away, and 2014 FE72 can reach 75 times farther away.

    There are likely thousands more such “Scattered Disk” objects which we simply can’t see yet. Their brightness from Earth falls as the 4th power of their distance from the Sun. So the ones that happen to be in the outer parts of their orbit are too dim to see.

    The Scattered Disk is objects which were “scattered” by the gravity of one of the major planets, some time after the Solar System formed, or by a close flyby of stars in the original cluster which the Sun was a member of. Cluster stars were close together, so close flybys were more common. They now have orbits which stay outside Neptune’s, so are unaffected by the 8 inner major planets. We suspect there is a 9th major planet out there among the scattered disk, due to clustering of the orbit parameters of some of it’s members. Since Planet 9, if it exists, would orbit 5-15 times farther than Thule, then obviously Thule isn’t in the outermost region.

  17. How big is Ultima Thule?

    And when will we see a hunt for Planet X (or whatever large planet is supposed to be lurking out in the Kuiper belt) ?

  18. There are billions of small comets out there. But they can wait. We have millions of asteroid and small comets in the Asteroid belt and in Trojan orbits.

  19. Yea, I am in favor of the “island hopping” colonization. There are tens of thousands of potential sites out there. Once we get fusion underway, bootstrapping one colony after the next will be doable.


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