On July 14th, 2015, the New Horizons made the first-ever flyby of Pluto. As if that wasn’t enough, the mission made history again with the flyby of the Kuiper Belt Object (KBO) 2014 MU69 on December 31st, 2018. This constituted the farthest encounter from Earth with a celestial object, which the team had nicknamed Ultima Thule – a mythical northern island beyond the borders of the known world in Medieval literature.
Unfortunately, this name has generated some controversy due to the fact that it is also the name white supremacists use to refer to a mythical homeland. So with the consent of the tribal elders and representatives of the Powhatan nations, the New Horizons’ team recommended a new name for the KBO. Henceforth, it will be known as “Arrokoth“, the word for “sky” in the Powhatan/Algonquian language.
Got your 3D glasses handy? Then prepare for the most realistic views of Ultima Thule yet! Yes, it seems that every few weeks, there’s a new image of the Kuiper Belt Object (KBO) that promises the same thing. But whereas all the previous contenders were higher-resolution images that allowed for a more discernible level of detail, these images are the closest we will get to seeing the real thing up close!
In 2015, the New Horizons mission became the first robotic spacecraft to conduct a flyby of Pluto. In so doing, the probe managed to capture stunning photos and valuable data on what was once considered to be the ninth planet of the Solar System (and to some, still is) and its moons. Years later, scientists are still poring over the data to see what else they can learn about the Pluto-Charon system.
For instance, the mission scienceteam at the Southwest Research Institute (SwRI) recently made an interesting discovery about Pluto and Charon. Based on images acquired by the New Horizons spacecraft of some small craters on their surfaces, the team indirectly confirmed something about the Kuiper Belt could have serious implications for our models of Solar System formation.
What’s going on in the distant reaches of our Solar System? Is there a Planet 9 out there?
Out in the frigid expanse of our System, there are bodies on orbital paths that don’t make sense in terms of our eight-planet Solar System. There seems to be an undiscovered body out there, several times more massive than Earth, shaping the orbits of some Kuiper Belt Objects (KBOs), and driving astronomers to look deeper and more thoroughly into the extreme reaches of our System.
What they’re looking for is the mysterious, and so far unproven, ninth planet.
On December 31st, 2018, the New Horizons probe conducted the first flyby in history of a Kuiper Belt Object (KBO). Roughly half an hour later, the mission controllers were treated to the first clear images of Ultima Thule (aka. 2014 MU69). Over the course of the next two months, the first high-resolution images of the object were released, as well as some rather interesting findings regarding the KBOs shape.
Just recently, NASA released more new images of Ultima Thule, and they are the clearest and most detailed to date! The images were taken as part of what the mission team described as a “stretch goal”, an ambitious objective to take pictures of Ultima Thule mere minutes before the spacecraft made its closest approach. And as you can no doubt tell from the pictures NASA provided, mission accomplished!
On December 31st, 2018, NASA’sNew Horizons mission made history by being the first spacecraft to rendezvous with the Kuiper Belt Object (KBO) named Ultima Thule (2014 MU69). This came roughly two and a half years after New Horizons became the first mission in history to conduct a flyby of Pluto. This latest encounter led to some stunning images of the KBO as the spacecraft made it’s approach.
But of course, these were not the last images New Horizons was going to capture of this object. While making its flyby of Ultima Thule on New Year’s Day, the spacecraft took a number of images that revealed something very interesting about Ultima Thule’s shape. Rather than consisting of two spheres that are joined together, Ultima Thule is actually made up of two segments – one that looks like a pancake, the other a walnut.
The Kuiper Belt, or the Edgeworth-Kuiper Belt, is home to ancient rocks. Kuiper Belt Objects, or KBOs, are remnants of the early planet-formation days of our Solar System. Small KBOs, in the 1 km. diameter range, have been theorized about for decades, but nobody’s every found one.
On December 31st, 2018, NASA and the New Horizon‘s team (plus millions of people watching the live stream at home) rang in the New Year by watching theNew Horizons mission make the first rendezvous in history with a Kuiper Belt Object (KBO). About thirty minutes after the probe conducted its flyby of Ultima Thule (2014 MU69), the mission controllers were treated to the first clear images ever taken of a KBO.
Since the first approach photographs were released (which were pixilated and blurry), the New Horizons team has released new images from the spacecraft that show Ultimate Thule in color and greater detail. It’s appearance, which resembles that of a snowman, beautifully illustrates the kinds of processes that created our Solar System roughly four and a half billion years ago.
In July of 2015, NASA’s New Horizons mission made history when it became the first spacecraft to conduct a flyby of Pluto. Since that time, the spacecraft’s mission was extended so it could make its way farther into the outer Solar System and become the first spacecraft to explore some Kuiper Belt Objects (KBOs). It’s first objective will be the KBO known as 2014 MU69, which was recently given the nickname “Ultima Thule” (“ultima thoo-lee”).
In January of 2016, astronomers Mike Brown and Konstantin Batygin published the first evidence that there might be another planet in our Solar System. Known as “Planet 9” (or “Planet X”, to those who contest the controversial 2006 Resolution by the IAU), this hypothetical body was believed to orbit at an extreme distance from our Sun, as evidenced by the fact that certain Trans-Neptunian Objects (TNOs) all seem to be pointing in the same direction.
Since that time, other lines of evidence have emerged that have bolstered the existence of Planet 9/Planet X. However, a team of researchers from CU Boulder recently proposed an alternative explanation. According to their research, it could be interactions between Kuiper Belt Objects (KBOs) themselves that might explain the strange dynamics of “detached objects” at the edge of the Solar System.
The researchers presented their findings at the 232nd meeting of the American Astronomical Society, which ran from June 3-7 in Denver, Colorado. The presentation took place on June 4th during a press conference titled “Minor Planets, Dwarf Planets & Exoplanets”. The research was led Jacob Fleisig, an undergraduate studying astrophysics at CU Boulder, and included Ann-Marie Madigan and Alexander Zderic – an assistant professor and a graduate student at CU Boulder, respectively.
For the sake of their study, the team focused on icy bodies like Sedna, a minor planet that orbits the Sun at a distance ranging from 76 AU at perihelion to 936 AU at aphelion. Along with a handful of other objects at this distance, such as Eris, Sedna appears to be separated from the rest of the Solar System – something which astronomers have struggled to explain ever since it was discovered.
Sedna was also discovered by Michael Brown who, along with Chad Trujillo of the Gemini Observatory and David Rabinowitz of Yale University, spotted it on November 14th, 2003, while conducting a survey of the Kuiper Belt. In addition to orbiting our Sun with a period of over 11,000 years, this minor planet and other detached objects has a huge, elliptical orbit.
What’s more, this orbit does not take them Sedna or these other objects anywhere near to Neptune or any other gas giant. Unlike Pluto and other Trans-Neptunian Objects (TNOs), it is therefore a mystery how they achieved their current orbits. The possible existence of a as-yet-undiscovered planet (Planet 9/Planet X), which would be about 10 times the size of Earth, is one hypothetical explanation.
After years of searching for this planet and attempting to determine where its orbit would take it, astronomers have yet to find Planet 9/Planet X. However, as Prof. Madigan explained in a recent CU Boulder press release, there is another possible explanation for the gravitational weirdness going on out there:
“There are so many of these bodies out there. What does their collective gravity do? We can solve a lot of these problems by just taking into account that question… Once you get further away from Neptune, things don’t make any sense, which is really exciting.”
While Madigan and her team did not originally set out to find another explanation for the orbits of “detached objects”, they ended up pursuing the possibility thanks to Jacob Fleisig’s computer modelling. While developing simulations to explore the dynamics of the detached objects, he noticed something very interesting about the region of space they occupy.
Having calculated the orbits of icy objects beyond Neptune, Fleisig and the rest of the team noticed that different objects behave much like the different hands on a clock. Whereas asteroids move like the minute hand (relatively fast and in tandem), larger objects like Sedna move more slowly like the hour hand. Eventually, the hands intersect. As Fleisig explained:
“You see a pileup of the orbits of smaller objects to one side of the sun. These orbits crash into the bigger body, and what happens is those interactions will change its orbit from an oval shape to a more circular shape.”
What Fleisig’s computer model showed was that Sedna’s orbit goes from normal to detached as a result of those small-scale interactions. It also showed that the larger the detached object, the farther it gets away from the Sun – something which agrees with previous research and observations. In addition to explaining why Sedna and similar bodies behave the way they do, these findings may provide clues to another major event in Earth’s history.
This would be what caused the extinction of the dinosaurs. Astronomers have understood for a long time that the dynamics of the outer Solar System often end up sending comets towards the inner Solar System on a predictable timescale. This is the result of icy objects interacting with each other, which causes their orbits to tighten and widen in a repeating cycle.
And while the team is not able to say that this pattern was responsible for the impact that caused the Cretaceous–Paleogene extinction event (which resulted in the extinction of the dinosaurs 66 million years ago), it is a fascinating possibility. In the meantime, the research has shown just how fascinating the outer Solar System is, and how much remains to be learned about it.
“The picture we draw of the outer solar system in textbooks may have to change,” said Madigan. “There’s a lot more stuff out there than we once thought, which is really cool.”
The research was made possible thanks to the support of the NASA Solar System Workings and the Rocky Mountain Advanced Computing Consortium Summit Supercomputer.