From what the belt is, to how it's helped change the classification of the solar system,
and more!
Join me as I reveal to you the facts and history of the Kuiper Belt!
9.
What Is The Kuiper Belt?
Despite it being a major part of our solar system, there are many who honestly don't
understand the grand scale and scope of the Kuiper Belt.
So allow us to give you some perspective on the matter.
The Kuiper Belt is a circumstellar disc in the outer Solar System, extending from the
orbit of Neptune (at 30 AU) to approximately 50 AU from the Sun.
It is similar to the asteroid belt, but is far larger—20 times as wide and 20 to 200
times as massive.
Like the asteroid belt, it consists mainly of small bodies or remnants from when the
Solar System formed.
While many asteroids are composed primarily of rock and metal, most Kuiper belt objects
are composed largely of frozen volatiles (termed "ices"), such as methane, ammonia and water.
The Kuiper belt is home to three officially recognized dwarf planets: Pluto, Haumea and
Makemake.
Some of the Solar System's moons, such as Neptune's Triton and Saturn's Phoebe, may
have originated in the region.
In many respects, the Kuiper Belt is the "end" of our solar system in terms of things like
the physical objects that are there and reachable.
The "edge" of the solar system is a slightly different matter as that would either be the
Heliosphere (if you go by magnetic fields) or the Oort Cloud, which is where the suns'
gravity reaches the end of its influence.
But either way, the Kuiper Belt is a major part of our solar system in the literal and
figurative sense.
Which is rather interesting when you think about it because for a very long time we didn't
understand what was truly in that realm of space as a whole.
8.
The Discovery Of The Kuiper Belt To truly understand the Kuiper Belt, we have
to dive into something you're very familiar with, Pluto.
After the discovery of Pluto in 1930, many speculated that it might not be alone.
The region now called the Kuiper belt was hypothesized in various forms for decades.
It was only in 1992 that the first direct evidence for its existence was found.
The number and variety of prior speculations on the nature of the Kuiper belt have led
to continued uncertainty as to who deserves credit for first proposing it.
But let's go back to the beginning and just break it down from there, shall we?
The first astronomer to suggest the existence of a trans-Neptunian population was Frederick
C. Leonard.
Soon after Pluto's discovery by Clyde Tombaugh in 1930, Leonard pondered whether it was "not
likely that in Pluto there has come to light the first of a series of ultra-Neptunian bodies,
the remaining members of which still await discovery but which are destined eventually
to be detected".
That same year, astronomer Armin O. Leuschner suggested that Pluto "may be one of many long-period
planetary objects yet to be discovered."
This is fascinating for all sorts of reasons, not the least of which is that the discovery
of Pluto should have been a finite discovery, or one that led to more study of the planet
and what it could mean as a whole.
Yet many scientists looked upon it and wondered if it was telling us everything we needed
to know about the region.
In 1943, in the Journal of the British Astronomical Association, Kenneth Edgeworth hypothesized
that, in the region beyond Neptune, the material within the primordial solar nebula was too
widely spaced to condense into planets, and so rather condensed into a myriad of smaller
bodies.
From this he concluded that "the outer region of the solar system, beyond the orbits of
the planets, is occupied by a very large number of comparatively small bodies" and that, from
time to time, one of their number "wanders from its own sphere and appears as an occasional
visitor to the inner solar system", becoming a comet.
That's not a bad way to describe what the Kuiper Belt really is, and he was right that
by modern classifications, the various items in the belt weren't able to go and become
fully-fledged planets.
But more on that in a bit.
Before we continue to break down everything that's going on with the Kuiper Belt, be sure
to like or dislike the video, that way we can continue to improve our content for you,
the viewer!
Also be sure to subscribe so that you don't miss ANY of our weekly videos!
7.
Continued Theories The more that astronomers wondered about the
Kuiper Belt, the more that speculations rose and fell about what it is, what it could be,
what it could've been, and more.
There were theories that the Kuiper Belt DID exist in the earlier parts of the solar system,
but that it wasn't around anymore now.
But for the most part, these were just wild guesses and theories as to whether the Kuiper
Belt was there and if it was there, how to define it.
Small advances were made, including finding new entities between Jupiter and Neptune in
terms of area, but it wasn't enough at the time.
Further evidence for the existence of the Kuiper belt later emerged from the study of
comets.
That comets have finite lifespans has been known for some time.
As they approach the Sun, its heat causes their volatile surfaces to sublimate into
space, gradually dispersing them.
In order for comets to continue to be visible over the age of the Solar System, they must
be replenished frequently.
One such area of replenishment is the Oort cloud, a spherical swarm of comets extending
beyond 50,000 AU from the Sun first hypothesised by Dutch astronomer Jan Oort in 1950.
The Oort cloud is thought to be the point of origin of long-period comets, which are
those, like Hale–Bopp, with orbits lasting thousands of years.
Why does this matter?
More than you realize.
Tom Quinn and Scott Tremaine ran a number of computer simulations to determine if all
observed comets could have arrived from the Oort cloud.
They found that the Oort cloud could not account for all short-period comets, particularly
as short-period comets are clustered near the plane of the Solar System, whereas Oort-cloud
comets tend to arrive from any point in the sky.
With a "belt", as Fernández described it, added to the formulations, the simulations
matched observations.
Reportedly because the words "Kuiper" and "comet belt" appeared in the opening sentence
of Fernández's paper, Tremaine named this hypothetical region the "Kuiper belt".
But this was still not the end of its origin.
6.
True Discovery In 1987, astronomer David Jewitt, then at
MIT, became increasingly puzzled by "the apparent emptiness of the outer Solar System".
Which is saying something when you consider how full of stuff our solar system really
is, but that's another matter entirely.
Regardless, he graduate student Jane Luu to help him find something that was "beyond Pluto".
Because in his words, "If we don't, no one will".
Ironically enough, they were using some of the same techniques to search for the objects
that were "beyond Pluto" that others had used to theorize about the Kuiper Belt as a whole.
The difference was that their technology was much stronger, much faster to report findings,
and they had more reach in terms of what telescopes they could use to search for objects.
After five years of searching, Jewitt and Luu announced on August 30, 1992 the "Discovery
of the candidate Kuiper belt object 1992 QB1".
Six months later, they discovered a second object in the region.
By 2018, over 2000 Kuiper belts objects had been discovered.
As various man-made probes approached the area, we further got a look at how the Kuiper
Belt was a disc-like object of incredible size and shape.
And what was found in it not only changed how we looked at the solar system, but it
changed how we defined it.
5.
Dwarf Planets In 1930, as noted earlier, Pluto was discovered,
and it was named as the 9th planet in the solar system.
However, as the theories and then findings of the Kuiper Belt were grown.
Pluto started to get a lot of question marks put around it in regards to whether it was
a true planet, or something else.
As other Dwarf Planets got found in the Kuiper Belt, including some that were equal to mass
or volume of Pluto if not bigger in some regards, the questions grew even more.
Plus, unlike Mercury-Neptune, these "planets" weren't exactly in its own "space", they were
surrounded by thousands upon thousands of objects that made a dense part of space.
Everything changed though in 2006, when the International Astronomical Union (IAU) decided
that after many decades of debates, they needed to figure out a concrete way of defining what
a planet was, no matter the consequences and backlash it may cause from the community at
large.
Thus, they made 3 defining "traits" for what a planet MUST be in order to be a true planet.
When these traits were made, it was determined that entities like Pluto, Eris, MakeMake Haumea
and more didn't meet the "qualifications" of being a true planet, and thus a new classification
was formed in that of "Dwarf Planets".
Though not many liked this classification, and many protest it to this day (including
many refusing to say that Pluto isn't a planet), the fact remains that to the general science
population, the planets end with Neptune, and the Kuiper Belt is its own entity entirely.
4.
Moons and Binaries A fairly large number of things in the Kuiper
Belt either have moons -- that is, significantly smaller bodies that orbit them -- or are binary
objects.
Binaries are pairs of objects that are relatively similar in size or mass that orbit around
a point (a shared center of mass) that lies between them.
Some binaries actually touch, creating a sort of peanut shape, creating what's known as
a contact binary.
Pluto, Eris, Haumea and Quaoar are all Kuiper Belt objects that have moons.
Telescope observations suggest the target of the NASA New Horizons spacecraft's 2019
flyby, known as 2014 MU69, may be a contact binary.
One thing that makes binary KBOs particularly interesting is that most of them may be extremely
ancient, or primordial, objects that have been altered little since their formation.
The various ideas for how these pairs form require a lot more objects than the present
day Kuiper Belt appears to contain.
One leading idea is that binaries may result from low-speed collisions between KBOs, which
would allow them to survive the impact and stick together due to their mutual gravity.
Such collisions were likely much more common billions of years ago, when most KBOs were
on similar orbits that were more circular and close to the plane of the planets (called
the ecliptic).
Today such collisions are much rarer.
They also tend to be destructive, since lots of KBOs are on now orbits that are tilted
or elliptical, meaning they crash into each other with greater force and break apart.
3.
Exploration The first spacecraft to enter the Kuiper Belt
region was NASA's Pioneer 10 spacecraft, when it crossed into the space beyond Neptune's
orbit in 1983.
But the first visit to an object in the Kuiper Belt was in July 2015, when NASA's New Horizons
spacecraft flew by Pluto and its moons.
On January 1, 2019, New Horizons successfully flew by Arrokoth, returning data showing Arrokoth
to be a contact binary 32 km long by 16 km wide.
The Ralph instrument aboard New Horizons confirmed Arrokoth's red color.
Data from the fly by will continue to be downloaded over the next 20 months.
No current plans are in place to send something else to the Kuiper Belt
2.
Planet 9 With the declassification of Pluto as a planet
(which we outlined earlier), the solar system as many know it is now down to 8 planets.
But, that may not fully be true.
There has long been speculation that there could be another planet out there in the solar
system.
Further study of the Kuiper Belt has added fuel to that fire in a very simple way.
You see, the outer planets of the solar system were first theorized and then found because
of not just looking in the right areas, but looking at the orbits of certain objects ahead
of them and how things are affected by gravity.
In the Kuiper Belt, there are objects that don't appear to be following the "natural
laws" of gravity, and thus there "must" be another major body out there that is affecting
them.
This has been dubbed "Planet 9", and because of this belief, many are searching the Kuiper
Belt for proof of this "true" ninth planet.
1.
What Will We Do With The Kuiper Belt?
This might seem like an odd question, but it's a legitimate one.
Because there has been much speculation about what humanity will do if we're able to travel
more in our solar system and thus eventually reach the Kuiper Belt.
Aside from studying the various objects that are there, the idea of mining some of the
larger rocks has been brought up.
Just as possible is the notion of setting up outpost stations on some of the dwarf planets
that are there.
Given the size and depth of the belt, the potential to do a lot of things there is mighty.
The only question being when we will be able to get there, and what technology we'll available
to do certain things.
Thanks for watching everyone!
What did you think of this look at the Kuiper Belt and how it not only was found, but how
it helped reshape our look at our own solar system?
Which of these things did you find the most interesting about the belt as a whole?
Do you think there's still so much more to learn about our solar system?
Let us know in the comments below, be sure to subscribe, and I'll see you next time on
the channel!