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Three and a half years after Pluto, New Horizons flew past Thule Ultima in the Kuiper belt

The American spacecraft that reached Pluto three years ago will tomorrow visit the most distant celestial body that a spacecraft has ever reached

A photograph of the celestial object Ultima Thule during the passage of the New Horizons spacecraft by it, January 1, 2019 (left) and a simulation of the shape of the object (probably an asteroid) and an estimate of its axis of rotation. Image: NASA
A photograph of the celestial object Ultima Thule during the passage of the New Horizons spacecraft by it, January 1, 2019 (left) and a simulation of the shape of the object (probably an asteroid) and an estimate of its axis of rotation. Image: NASA

On the maps of ancient Greece and ancient Rome, Thule was the northernmost island. Among other things, it is currently identified with the islands of Scotland, Iceland or Greenland. From the Hellenic maps arose the phrase ultima thule - the last thule - a term that can be translated as "the end of the world" - the farthest place. In medieval literature, the expression took on the meaning of a place that is beyond the borders of the known world. Therefore, the name, chosen in a public poll by the American space agency, is very suitable for the most distant celestial object that a spacecraft will visit.

You can barely see

The American spacecraft New Horizons was launched in 2006 to study the dwarf planet Pluto. After almost a decade of flight, she passed by it in July 2015 and photographed it and its moons up close. Even long after the transit, the spacecraft continued to transmit images of Pluto and additional information about it and its moons. Pluto is the largest object known to us in the region known as the Kuiper Belt - a vast region containing asteroids and other celestial bodies in the outermost part of the solar system. After the pass by the dwarf planet, the plan was for the spacecraft to take close-up pictures of other objects in the Kuiper Belt, and the search for the next target began even before it got close to its original target.

A short passage that should reveal an unknown celestial gram. New Horizons visualization near Thule Ultima (not to scale) | Source: NASA
A short passage that should reveal an unknown celestial gram. New Horizons visualization near Thule Ultima (not to scale) | Source: NASA

The object that was eventually chosen was discovered in 2014 in observations by the Hubble Space Telescope, which were made for this very purpose. Its official name is currently 2014MU69, and the chosen name is expected to be confirmed only after the spacecraft passes by it. The discovery involved not much more than the very existence of this body and the calculation of its trajectory, so that it would intersect with the trajectory of the spacecraft moving away from the sun at a speed of more than a million kilometers each day, and its ability to change direction is extremely limited. After no ground-based telescope could detect relevant celestial objects in the Kuiper belt, due to the enormous distance, the researchers turned to the space telescope. Although the distance between it and the ground telescopes is only about 500 kilometers, Hubble can see much further, because it is outside the atmosphere and it does not absorb and distort the light that reaches it.

The light reflected from Ultima Thula is so weak that most observations of it are not direct: with non-space telescopes, including the aircraft-mounted SOFIA telescope, researchers can only see it when it obscures the light of distant stars. This is a very challenging method of observation, which requires very precise timing of the observation and viewing from exactly the right angle. Therefore, since its discovery, only a few observations have been successfully made on it, and the knowledge about it is very poor.

Accurate observation of concealment. Thule Ultima passes in front of a star (in the red circle) and hides it in the blink of an eye Photo: NASA
Accurate observation of concealment. Thule Ultima passes in front of a star (in the red circle) and hides it in the blink of an eye Photo: NASA

close but far

The researchers estimate that Ultima Tula is a body that is 30-20 kilometers long and its shape is relatively elongated. Several observations indicate that it may have the general shape of two connected spheres, and some researchers have hypothesized that they are not connected, but orbit each other at a very short distance. According to orbital calculations, it completes one orbit of the Sun every 296 years (Pluto's orbit lasts 248 Earth years), at a distance of approximately 6.5 billion kilometers, which is approximately 43 astronomical units (that is, 43 times the distance of the Earth from the Sun).

If all goes well, the New Horizons spacecraft will pass on January 1 at a distance of only about 3,500 kilometers from Ultima Thule. It may sound far, but it is a third of the distance from which the spacecraft photographed the dwarf planet Pluto. Ultima Thule is, of course, a much smaller body, but the researchers still expect that the sophisticated cameras of the spacecraft will provide them with high-quality images even from a great distance that will allow them to distinguish details about 30 meters in size on the surface of the tiny sky.

Since the spacecraft is moving at a speed of more than 14 kilometers per second, the entire passage will be very short. Its peak should occur on Tuesday at 7:33 am (Israel time). However, due to its enormous distance from Earth, it will take no less than six hours for the signals from it to reach us, so that only in the afternoon we will be able to see the first images of the farthest celestial gram that a spacecraft has reached.

to the end of the world

During the short pass close to Ultima Thule, the spacecraft will take many pictures and measure additional data such as temperature, radiation, the concentration of particles in space and more. After sending the first images immediately after the upcoming transit, the spacecraft is supposed to continue sending data and information from the transit to Earth for almost two years, until September 2020, due to the limited bandwidth that prevents it from sending all the information in a short time. The researchers hope to learn many details about Ultima Thule from this data: its structure, chemical composition, self-rotation, if there are gases or other particles around it, and more. Based on this information, the researchers will try to better understand the history of the Kuiper belt and try to complete the picture of the formation of the entire solar system.

After the transition, New Horizons will continue to move away from the Sun at an enormous speed - more than 50 thousand kilometers per hour. In fact, there is no way to stop it - the fuel it carries is for direction corrections, but not enough to slow it down so that it enters orbit around a planetary body, or even around the Sun. However, in the coming years the spacecraft is not expected to encounter any additional objects. For now, its mission is supposed to end in mid-2021, but if its instruments continue to function, it is possible that NASA will try to locate another body in the Kuiper belt and direct it to pass by it.

In 2038, the spacecraft is expected to reach a distance of 100 astronomical units and actually cross the Kuiper belt and leave the heliosphere - the range of influence of the solar wind - into the interstellar region where two Voyager spacecraft are currently sailing. If its systems still work - it will be more than expected according to the original plan but certainly within the scope of the possible - it will be able to join these spacecraft, which are currently transmitting information from outer space itself. The spacecraft receives its power supply from a generator that utilizes the heat generated by the nuclear fission of plutonium. If the plutonium runs out and the instruments stop working, New Horizons will exit the solar system as a cold, still box, and will probably continue in its orbit until the end of time. It will leave us with some records, such as the photographs farthest from Earth, and a glorious legacy of the first spacecraft, meanwhile the only one, that closely studied objects in the Kuiper belt - the edge of the known world.

16 תגובות

  1. Yehuda
    If you read the links you would read that the "pioneer anomaly" weakens over time. chess!

    And in any case - I would love to understand from you how elastic collisions create attraction. As Israel says - just explain this to me.

    You say that the collisions are rare and therefore your particles behave differently from a gas, but after that you claim that your gravity also acts on individual atoms.

    So again - just explain to me how elastic collisions cause attraction. On the other hand, New Horizon will dance Kankan - as long as your theory doesn't work - it doesn't work.

  2. for miracles
    I will not delve into the entire sequence of nonsense you "cite" regarding my theory, but I will address my proposal regarding the use that can be made of New Horizon as a continuation of its activity in space.
    Well, the proposal that you call in your wisdom "an irrefutable proposal" was already put forward by others at the beginning of the mission and it would be a shame if NASA had people like you who would cancel the "refutable proposal" outright.
    Just type in Google:
    new horizons pioneer anomaly
    And you will already receive dozens of websites and links on the "ridiculous" topic
    And I have a question for you Nisim - do you really think it's not worth testing?, what are you afraid of?, God forbid it turns out that corrections should be made to the existing theories?, God forbid it turns out, for example, that maybe your favorite dark matter might be causing a tiny friction after all???, A tiny friction between baryonic matter and dark matter.
    Here is for example a correction that will definitely not prove my theory.
    And maybe what dear Nissim expects will happen, here too it will be proven that the heating of the engines is the cause of the deceleration, but here unlike the Pioneer probes that were left without fuel for the experiments, here they will rotate New Horizon 180 degrees in the direction of movement and they will see that the same Pioneer deceleration becomes an acceleration of the same magnitude,
    And a savior has come to Zion and science will be saved from the "refutable proposal" of Sabdarmish and Co.
    Dear Nissim, sorry but you lack courage and intellectual courage!
    Shabbat shalom to miracles and to all science responders

  3. Yehuda
    You have a theory that can't work. I explained to you why, but the explanations "do not seem to you".

    Am I the one who is fixed? Maybe... but I'm not ready to throw away all of physics because of a theory that is obvious to anyone who has opened a physics book that it cannot work.

    I have no intention of making a ridiculous offer to NASA.

  4. Miracles
    I'm pretty tired of the endless debate with you on this topic.
    After all, up to a distance of thousands of meters there is almost no difference in the behavior of the planets or asteroids, according to Newton or according to pushing gravity, so where do you get all this nonsense from??-
    "That NASA doesn't know how to do calculations?", Thuli doesn't orbit the sun at all", and all kinds of other nonsense.
    For my part, they won't do repeated and responsible tests for the Pioneer anomaly, which is apparently what they will really do because NASA is full of fixed people like you who don't think outside the box. You will, of course, see a victory for the non-real scientific examination of the anomaly, because the fear of hearing that your faith, rooted in the words of the leading experts in science, will be destroyed, will prevent you from changing your fixed opinion. point.
    That's the end of the endless argument with you. I gave a good idea. They will want to do it, they won't. they won't do it.
    Good night
    And by the way, maybe you with your good English will send my proposal to NASA?, I really wonder what they will answer???
    Good night a second time

  5. Yehuda
    They managed to bring the spaceship together with Thuli.... Do you really think that NASA does not know how to do calculations? Thuli is supposed to go around the sun in your opinion? According to your theory - no. After all, because of deflection, your particles did not have to be blocked by Thuli.
    Or are the bypass laws incorrect?

  6. for miracles
    I still think it would have been better to verify the exact explanation for the anomaly.
    But I won't start a campaign of persuasion, I'll just point out that the cost of the test is really tiny because the probe is already there at a distance of 43 astronomical units and has fuel for all kinds of rotations and exercises.
    All the best

  7. Yehuda
    Let's be precise - there is an explanation that is accepted by the professionals, but it does not match your theory and therefore "I don't think so..!"
    Here is the quote from Wikipedia:
    interplanetary medium (imperfect vacuum).

    By 2012 several papers by different groups, all reanalyzing the thermal radiation pressure forces inherent in the spacecraft, showed that a careful accounting of this explains the entire anomaly, and thus the cause was mundane and did not point to any new phenomena or need for a different physical paradigm.[2][3] The most detailed analysis to date, by some of the original investigators, explicitly looks at two methods of estimating thermal forces, then states "We find no statistically significant difference between the two estimates and conclude that once the thermal recoil force is properly accounted for, no anomalous acceleration remains.”[4]

    The entry describes the studies in detail and even refers to 55 links on the subject.

    A serious scientist tries to disprove the theory he believes in. You do the opposite - you dig for every shred of evidence that fits your theory, and blatantly ignore any rebuttal.

    And the most blatant disregard is the simple fact that elastic collisions cannot create "gravity"!

  8. Below is a quote on the Hebrew Wikipedia on this topic
    a quote:
    "The Pioneer Anomaly, or Pioneer Effect, is an unexpected deviation of several objects visiting the outer solar system, especially Pioneer 10 and 11, from the trajectory predicted by general relativity.
    Both probes are in orbit outside the solar system, and are slowing down under the influence of the sun's gravity. However, an accurate analysis of their movements shows that they slow down a little more than expected. The effect can be described as an additional weak acceleration towards the Sun.
    Today there is no universally accepted explanation for the phenomenon.
    After the speed and position data of the Pioneer 10 and 11 probes arrived as measured by the instruments on them, it was discovered that even when taking into account all the forces acting on the probes, there remains an unexplained acceleration of (8.74 ± 1.33)×10-10 meters per second squared, towards the sun
    The data from Galileo and Myolisis also indicated a similar effect, although for a number of reasons, such as their proximity to the sun, these probes could not provide unequivocal conclusions." End quote.
    In short, the phenomenon was discovered and tested in several probes. The claim that it is heat coming out of the probe engines is possible with many other possibilities.
    For the sake of justice and integrity, I will not deny that a world full of gravity-pushing particles (as I believe) will slow down spacecraft and probes of all kinds, and Nimes is right in claiming that this is in line with my belief in gravity-pushing, so I would like the anomaly to be checked for confirmation.
    All the best, miracles
    And others

  9. Yehuda
    If there was something in the Pioneer Anomaly that affects gravity, then it should also affect the orbits of other objects at the same distance. If you open Wikipedia you will find that this is not the case.

    Yehuda, don't insult me. We both know why the solution to the anomaly doesn't seem to you.

  10. Dear Nissim
    Who even mentioned my theory?? you dream at night about my theory annoying your wife with my theory building wires wires of nonsense and toys
    A quote from your response: "The interpretation of the phrase "not acceptable to me" - with Yehuda - is "it contradicts my theory, therefore it is not true, and all the scientists at NASA are liars and fools... they took my toy!!!!
    It's a phrase that suits dark religious people (any religion) when talking about the evidence for evolution...end quote.
    Excuse me Nissim, you have a subdermic syndrome that has not yet been precisely defined. SA What I am saying is that NASA's explanation of the Pioneer anomaly should be re-examined. And if there is a body in the far reaches of the solar system that we don't exactly know what to do with, then I make a proposal with the help of which you can shut Judah up once and for all or maybe, you will shut up, even if it is not acceptable to you.
    And by the way, I checked and saw that I didn't write any article about the Pioneer anomaly on my website, so maybe it's time to write an article about the Pioneer anomaly, it's unacceptable for me not to write an article about something so important: - the existence of significant friction in movement in the "emptiness" of the cosmos
    And by the way, regarding evolution, read my article on "Evolution of Creationism" and continue watching the movie Peri Amali
    And the fruit of the labor of the young director Shahar Arieli "The Research" and you will see that the issues of evolution are not so simple and clear.
    Good night
    Please respond gently

  11. The name of the celestial body is pronounced in English "to-li". The origin of the name is Latin and means "the northernmost place" - it appeared on ancient maps as the name of several places throughout history (including islands of Scotland and islands of Norway).

    Kuyper is pronounced in English "Keifer". The original is Dutch, and cannot be pronounced accurately in English (like Huygens)

    The interpretation of the phrase "not acceptable to me" - for Yehuda - is "it contradicts my theory, therefore it is not true, and all the scientists at NASA are liars and fools... they took my toy!!!!".
    This is an expression that suits dark religious people (any religion) when talking about the evidence for evolution...

  12. With the completion of the tasks assigned to New Horizon, I would suggest using the New Horizon spacecraft to test the "Pioneer Anomaly". To remind you, an unexplained deceleration was discovered in the Pioneer flight, in the direction of the sun. After thirty years of research, NASA decided that the slowdown is due to Pioneer heating up in exactly the direction and intensity required. It goes without saying that this explanation, which is accepted by everyone including miracles, is not acceptable to me.
    Please respond gently
    Happy New Year

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