Dwarf Planets: The Lesser Worlds
Summary
TLDRThe video explores the fascinating world of dwarf planets and minor planets within our solar system. It discusses the reclassification of Pluto and other celestial bodies, highlighting the complex features and intriguing properties of these distant worlds. The video delves into the composition, discovery, and unique characteristics of notable dwarf planets like Ceres, Eris, Haumea, and Makimaki, as well as objects in the Kuiper Belt such as Arakoth. Through detailed analysis and exploration, it reveals the unexpected complexity and diversity of these far-reaching celestial bodies.
Takeaways
- 🌍 Our solar system consists of eight main planets, four rocky terrestrial planets, and four gas giants.
- 🌐 Beyond the orbits of the main planets, there are numerous small icy worlds known as minor planets, including Pluto, which was reclassified as a dwarf planet in 2006.
- 🔍 The term 'minor planet' is broad and includes any astronomical object orbiting the sun or another star that is not a planet or a comet.
- 🌟 The International Astronomical Union (IAU) redefined the criteria for a planet in 2006, adding the requirement that a planet must clear its orbital path, leading to the reclassification of Pluto as a dwarf planet.
- 🪐 Dwarf planets, like Pluto, are large enough to be rounded by their own gravity but do not dominate their surrounding space.
- 🌕 Ceres, the first dwarf planet ever discovered and visited, is the largest object in the asteroid belt and is composed mostly of rock and water ice.
- 🌌 The Kuiper Belt, beyond the orbit of Neptune, is a vast region of icy objects and debris, home to many dwarf planets and other small bodies.
- 🌑 Pluto, once considered the ninth planet, has a complex landscape with ice mountains, valleys, craters, and a possible subsurface ocean.
- 🌠 Eris, the second largest dwarf planet, is the most massive and has a moon named Dysnomia, indicating its size and mass.
- 🌈 Haumea, another dwarf planet, has an elongated shape and a ring system, making it the first trans-Neptunian object with a ring.
Q & A
What are the two main types of planets in our solar system?
-The two main types of planets in our solar system are the rocky terrestrial planets and the gas giants.
What is the term used to describe small icy worlds orbiting in the outer reaches of the solar system?
-These small icy worlds are known as minor planets.
Why was Pluto reclassified as a dwarf planet in 2006?
-Pluto was reclassified as a dwarf planet because it is too small to be considered on the same level as the Earth or Saturn and does not clear out its orbital path.
What is the difference between a planet and a dwarf planet according to the International Astronomical Union's definition?
-A planet must orbit the sun, be in hydrostatic equilibrium (spherical shape due to its own gravity), and clear out its orbital path. A dwarf planet meets the first two criteria but does not clear out its orbital path.
How many known minor planets are there in the solar system?
-There are almost 800,000 known minor planets in the solar system.
What is the significance of Ceres in the asteroid belt?
-Ceres is the largest object in the asteroid belt, accounting for about a third of the belt's total mass, and was reclassified as a dwarf planet in 2006.
What evidence suggests that Ceres might have had a subsurface ocean?
-Shiny bright patches on Ceres' surface, which are deposits of magnesium salt residue, indicate that there might have been liquid water eruptions from a subsurface ocean.
What is the Kuiper Belt and what is its significance?
-The Kuiper Belt is a thick, rotating disk of icy objects and debris beyond the orbit of Neptune. It is significant because it is thought to contain well-preserved artifacts from the early solar system.
What are the characteristics of Pluto's landscape?
-Pluto's landscape consists of vast mountain ranges made of solid ice, valleys, craters, flat plains, and ice caps of frozen methane. It is thought to have a rocky core, a water ice mantle, and an icy crust.
What is the significance of the discovery of Eris, Haumea, and Makemake?
-The discovery of these dwarf planets prompted the International Astronomical Union to redefine the criteria for what constitutes a planet, leading to the reclassification of Pluto and the recognition of these bodies as dwarf planets.
Outlines
🌍 Our Solar System's Diverse Planets
This paragraph introduces the structure of our solar system, highlighting the terrestrial planets close to the sun, which are primarily composed of rock, and the gas giants further out. It also discusses the reclassification of Pluto from a planet to a dwarf planet in 2006 due to its inability to clear its orbital path. The paragraph emphasizes the existence of minor planets, which are astronomical objects that orbit the sun but are neither planets nor comets. The International Astronomical Union's definition of a planet includes criteria such as orbiting the sun, being in hydrostatic equilibrium (having a spherical shape due to gravity), and clearing its orbital path.
🪐 Dwarf Planets: The Lesser-Known Celestial Bodies
The focus shifts to dwarf planets, which are not as large as traditional planets but still possess intriguing properties. Ceres, the first dwarf planet discovered, is highlighted as an example. Initially mistaken for a comet and later classified as an asteroid, Ceres was reclassified as a dwarf planet due to its size and composition. It is the largest object in the asteroid belt and is believed to contain a significant amount of water, possibly even a subsurface ocean. The paragraph also discusses the exploration of Ceres by NASA's Dawn spacecraft and the implications of its findings on our understanding of dwarf planets.
🌌 The Kuiper Belt: A Treasure Trove of Icy Objects
This paragraph delves into the Kuiper Belt, a vast region beyond the orbit of Neptune that is densely populated with icy objects. The objects in the Kuiper Belt are thought to be well-preserved remnants from the early solar system, providing insights into its formation. The paragraph describes the discovery and exploration of Pluto, which was once considered the ninth planet but was reclassified as a dwarf planet. The New Horizons mission's flyby of Pluto revealed a complex landscape with ice mountains, valleys, and a possible subsurface ocean. The paragraph also touches on the unique features of Pluto, such as its heart-shaped region, Sputnik Planitia, and its five moons.
🌑 Pluto's Complex Landscape and Atmosphere
The paragraph explores Pluto's diverse landscape and its atmospheric conditions. Despite its small size, Pluto has a surprisingly detailed surface with ice mountains, valleys, and plains. It is thought to have a rocky core and a water ice mantle. Pluto's thin atmosphere, composed of nitrogen, methane, and carbon monoxide, is influenced by its low gravity. The paragraph also discusses the possibility of a subsurface ocean on Pluto and the implications of its active surface features, such as the lack of impact craters in the Sputnik Planitia region.
🌠 The Discovery and Properties of Other Dwarf Planets
This paragraph discusses the discovery and properties of other dwarf planets in the Kuiper Belt, such as Eris, Haumea, and Makemake. Eris, the most massive dwarf planet, was discovered in 2003 and is similar in size to Pluto. Haumea, with its elongated shape, is thought to be the result of a collision and has a ring system. Makemake, discovered in 2005, is smaller than Haumea and has a surface covered in frozen methane. The paragraph also touches on the debate that led to the reclassification of Pluto and the criteria for defining a planet, which now includes clearing its orbital path.
🌈 Arakoth: The Smallest and Most Primitive Object Explored
The final paragraph introduces Arakoth, a small solar system body discovered in 2014 and visited by the New Horizons spacecraft. Arakoth is unique for its double-lobed shape, resembling a snowman. Its red color indicates that it has been exposed to cosmic radiation and ultraviolet light for a long time, suggesting that it is ancient and well-preserved. The composition of Arakoth, which includes methanol water ice and organic molecules, is distinct from other objects explored. The paragraph concludes by reflecting on the complexity and resilience of dwarf planets and the vast potential for discovery in the Kuiper Belt and beyond.
Mindmap
Keywords
💡Terrestrial Planets
💡Gas Giants
💡Minor Planets
💡Dwarf Planets
💡Hydrostatic Equilibrium
💡Ceres
💡Kuiper Belt
💡Pluto
💡Eris
💡Haumea
💡Makimaki
Highlights
The solar system consists of eight planets, four rocky terrestrial planets, and four gas giants.
Pluto was reclassified as a dwarf planet in 2006, losing its status as the ninth planet.
Minor planets, including dwarf planets, are astronomical objects orbiting the sun that are not planets or comets.
There are nearly 800,000 known minor planets in the solar system, archived by the Minor Planet Center.
The term 'minor planet' has evolved to include dwarf planets and small solar system bodies (SSSBs).
Ceres, discovered in 1801, is the first dwarf planet ever discovered and visited.
Ceres is located in the asteroid belt and is composed mostly of rock and water ice.
Ceres is thought to have a subsurface ocean and pockets of liquid water.
The Kuiper Belt is a vast region beyond the orbit of Neptune, containing icy objects and debris.
Pluto, a Kuiper Belt Object, was discovered in 1930 and has a complex and mysterious landscape.
Pluto's surface temperatures can fall as low as -240 degrees Celsius, causing gases to freeze.
Pluto's heart, the Tombaugh region, is a unique area with a smooth icy surface and no impact craters.
Eris is the second largest and most massive dwarf planet in the solar system.
Haumea has an elongated egg shape and is believed to be the result of a large collision.
Makimaki is a small, bright trans-Neptunian object with an unusual orbit.
Aracoth, discovered in 2014, is a small solar system body with a double-lobed shape.
Dwarf planets exhibit complex processes such as temporary atmospheres, ring systems, and tectonic activity.
Transcripts
right now
unless you're somehow watching this from
space you are situated on a planet
a giant sphere of material and heat
ours is made mostly of rock as are the
three other planets in our backyard
further away from the sun lie four huge
balls of hydrogen and helium
in different states these constitute the
eight planets of the solar system
four rocky terrestrial planets and four
gas giants
however this is far from the full
picture
the solar system is also home to another
type of world
between and beyond the orbits of the
eight conventional planets
lie dozens and dozens of small icy
worlds
orbiting in the outer reaches of the
solar system
these are known as minor planets or at
least they used to be
the best example is of course pluto
in 2006 pluto was reclassified as a
so-called
dwarf planet voiding its status as the
solar system's ninth planet which it had
held for many decades
pluto ultimately is just too small to be
considered on the same level as the
earth or saturn
however there is more to it than just
pluto's size
the actual story behind pluto's
reclassifications started with the
discoveries of several similar remote
minor planets
and now pluto sits among a family of
almost worlds
dwarf planets which despite being much
smaller than the earth
still exhibit fascinating and unlikely
properties
today we will experience these frozen
far out worlds first hand
the term minor planet is a broad
classification
defined as any astronomical object in
orbit around the sun or another star
which is neither a planet
nor a comet most of the time this is
because it is either too small to be a
planet
or it doesn't have the same impact on
its surroundings as the other planets do
while pluto is the obvious one there are
almost eight 800
000 known minor planets in the solar
system alone
which are archived by the minor planet
center
up until about 15 years ago the terms
minor planet
planetoid and asteroid were all used
synonymously
referring to a body not large or round
enough to be considered a conventional
planet
however since the term was coined we
have reached and studied the outer solar
system
a place where rocky and icy material is
much more abundant
leading to discoveries which have
blurred the lines between what can be
considered a planet and what can't
as a result the terminology has become
more complicated over time
and the need for clarifications arose
and so in 2006 the international
astronomical union voted to amend their
definition of a planet
before this a planet had to satisfy two
simple criteria
the first being that it needs to orbit
around the sun obviously
the other thing is that it needs to be
in hydrostatic equilibrium
in other words large and heavy enough
that it becomes rounded by its own
gravity
giving it a spherical shape
under these criteria pluto was
discovered and named the solar system's
ninth planet
which it remained for many decades but
with the definition change
came a third criterion now a planet must
also
clear out its orbital path as they
travel around the sun
the large planets either clear out or
consume material in their way
dispersing the rubble of the early solar
system and clearing themselves a region
of space which they dominate and
influence
under this revised definition however
pluto doesn't fit the bill
the reason being because it orbits
within a large band of debris near the
outer rim of the solar system
and thus doesn't clear out its region of
space
thus it lost its planetary status to the
disappointment of many
following the rule change the iau then
reclassified the term minor planet into
two new sub-categories
dwarf planets and small solar system
bodies
or sssbs dwarf planets
like pluto are the nearly worlds which
are large enough to be rounded but don't
dominate their surrounding space
a small solar system body is anything
else that isn't a comet
like a large asteroid or the micro
satellites which orbit such
asteroids or perhaps the icy objects
beyond the reaches of neptune
known as trans-neptunian objects or tnos
as a result the term minor planet has
become outdated
but it is still used to encompass both
types
today however we are going to be
focusing for the most part on dwarf
planets
while not as large or structured as
their planetary counterparts
they can still house astounding
properties the likes of which we never
expected to find on worlds so far away
from the sun
and while most of these worlds lie
billions of kilometers away
and are thus very difficult to reach and
study we do have one relatively close to
us
the first dwarf planet ever to be
discovered and visited
ceres ceres was discovered in 1801
by giuseppe piazzi who noted it while he
was searching for stars
initially he mistook it for a comet and
named it series ferdinandia
however within a year astronomers had
identified it as another planet
and shortened its name to ceres named
after the roman goddess of corn and
harvests
it lies over 400 million kilometers away
from the sun
within the asteroid belt a ring
consisting of pieces of rock between the
orbits of mars and jupiter
after initially being mistaken for a
comet and then for a planet
ceres was reclassified as just another
asteroid among the many others in the
belt
however it sticks out as an outlier
against its rocky neighbours
at just under 1000 kilometers in
diameter it is by far the largest object
within the belt
and also accounts for about a third of
the belt's total mass
and so it was among a host of objects to
be reclassified as dwarf planets in
2006.
putting aside the anthropocentric
terminology however
it seems strange doesn't it a dwarf
planet here
in a sparsely populated belt where
nothing else like it exists
too large to be an asteroid but too
small to be another planet
and so in 2015 we visited the world
in an attempt to better understand its
origins
nasa's dawn spacecraft made flybys of
series
sending back detailed images and giving
us clues to its past
it is composed of mostly rock and water
ice its core
and mantle are thought to constitute a
layer of ice which
if it exists would mean that ceres has
more water than the earth
in a solid form at least but buried
beneath its icy cratered surface
is thought to have pockets of liquid
water
surviving from a subsurface ocean which
once flowed
above ground on the surface of the dwarf
planet
it is now thought that ceres is the
remains of an embryonic planet
a small rocky body which was
accumulating material
in the early solar system just like the
earth
it is now believed that ceres may have
had an ocean of magnesium salt water
flowing on its surface billions of years
ago however its destiny was cut
short when its neighbouring planets
jupiter in particular
scattered and consumed the vast majority
of material in the area
the same material that grew the
terrestrial planets and the gas giants
as such ceres was unable to grow larger
and so was far too small to hold on to
its primordial atmosphere
and so the budding proto-planet died
and was cast into the asteroid belt
destined to float silently among rubble
and debris
when its atmosphere was lost to space so
too was the ocean
and its remnants are now buried beneath
the surface in its last surviving
pockets
we can see evidence of these liquid
water pockets in these shiny bright
patches on the surface
these highly reflective mounds are
actually deposits of magnesium salt
residue
left over from liquid water eruptions in
the mantle
which spilled out onto the surface
whether anything could survive in these
underground pockets of water remains a
mystery
one thing's for sure though ceres is a
true gem
hidden within a dead and desolate region
of the solar system
one of the reasons there aren't any
other dwarf planets in the asteroid belt
is because the belt is so sparsely
populated
most of its material has been depleted
and the few objects that remain
are scattered millions of kilometers
apart
however significantly further away than
the asteroid belt beyond the orbit of
all eight of the planets
lies another far larger belt of material
the kuiper belt the kuiper belt is a
thick
rotating disk of icy objects and debris
similar in structure to the asteroid
belt but much larger
and more densely populated the objects
in the kuiper belt are thought to have
formed very early on in the solar
system's life
rocks began appearing out of the dust
around the young sun
which condensed to form the planets and
any primordial rocky pieces that were
not consumed were scattered
and much of it drifted and settled into
this massive belt
unfathomably far away from the sun
because the objects within are so far
away from the sun's light
they have only been warmed and
irradiated slightly in the billions of
years since their formation
and so are thought to be well-preserved
artifacts which can allow us to examine
what the solar system was like back then
the kuiper belt begins at just beyond
the orbit of neptune
around 30 astronomical units away so
that's 30 times further than the earth
is from the sun
and it extends out to around 50 times
further away
thus it is so remote and vast that it is
a place that we have only just begun to
explore and understand
objects within the kuiper belt are
referred to quite simply
as kuiper belt objects or kbos
scattered within the kuiper belt's
expanse are hundreds of millions of
cometary nuclei
hundreds of thousands of objects larger
than 100 kilometers in diameter and
perhaps hundreds of small
cold dwarf planets which have yet to be
discovered
and crucially because they all exist and
orbit within the bounds of this belt
they do not clear out their orbital
paths or dominate the space around them
effectively excluding them from being
planets
however that doesn't stop them from
having intriguing planet-like features
such as transient atmospheres which
exist as gas
in an atmospheric layer when faced with
the light of the sun
before collapsing down into frost on the
surface during the night
this brings us to our most distant
honorary planetary neighbour
pluto pluto
was discovered in 1930 and it is named
after the roman god of the underworld
it is classed as a kuiper belt object
and a dwarf planet today
but it was long considered to be the
solar system's ninth planet
it is smaller than all eight of the
solar system's main planets
and orbits considerably further out
averaging a distance of about 39
astronomical units it orbits the sun
in both an elliptical and tilted orbit
which can take it as far away as 50
astronomical units
to the very distant outer edge of the
kuiper belt
its small size low visibility and sheer
distance from the earth makes it a very
tricky world to study
until about five years ago we only had
very low detail
observations of the dwarf planet but all
this changed in 2015
when nasa's new horizons mission flew by
pluto
revealing it in brilliant detail for the
first time
and what a revelation it was the data
we've collected from pluto since has
revolutionized our ideas on the
complexity of worlds this far away from
their parents star
despite being small around 2 370
kilometers in diameter
pluto still has a surprisingly detailed
and mysterious landscape
consisting of vast mountain ranges made
of solid ice
some several kilometers high it also has
valleys craters flat plains and even ice
caps of frozen methane
it is thought to have a rocky core
surrounded by a water ice mantle
topped by an icy crust because it is so
far away
its surface temperatures can fall to as
low as -240 degrees celsius
so cold that nitrogen and methane gases
freeze down onto its surface
and into frozen nitrogen ice sheets
across its vast plains
[Music]
for the most part pluto is a scarred
cratered world
except for in one unusual place like
nowhere else found in the solar system
for this we have to look to the tombau
region also known as pluto's heart
it is a large double lobed plane of
smooth volatile ice sheets
its western lobe is known as sputnik
planitia
here there are no impact craters instead
the smooth icy surface is intersected by
cracks which crisscross the ice sheet
showing evidence of convection currents
below the surface
even at this size and distance from the
sun part of pluto's crust
is active we're not sure exactly what
drives this convection
but it is responsible for gently turning
the nitrogen ice sheet over
resurfacing it and keeping it fresh thus
explaining the lack of craters
one theory is that this active nitrogen
ice sheet floats atop
a buried subsurface ocean of liquid
water
that has existed for billions of years
which was exposed by a huge impact
collision this collision would have torn
off a huge chunk of pluto's crust
resulting in radioactive decay within
the basin at left
which may be the elusive heat source
that is churning the ice sheet to this
day
during the day pluto's volatile ices
sublimate directly
into a gas which expands into an
atmospheric layer of nitrogen
methane and carbon monoxide
because it has such low gravity its
atmospheric layer is held down much less
tightly than it is on earth
allowing its atmosphere to extend much
further out into space
and as the new horizon spacecraft flew
away from pluto
it turned back and saw this inflated
atmospheric layer in all of its
breathtaking glory
pluto also has no less than five moons
the largest sharon is about half the
size of pluto itself
making it the largest moon relative to
its parent in the solar system
and also one of the closest so close in
fact that the gravitational center of
the pluto system
is not actually pluto itself and thus
pluto and sharon are generally referred
to as a barycenter
the other four moons nyx hydra styx
and kerberos are all much smaller
resembling fragments more so than moons
we're not sure how the pluto sharon
system came to be
but the leading theory is that it was
formed by a collision of kuiper belt
objects
pluto and sharon have similar densities
which suggests that they may have once
been part of a single body
for now though that remains just a
theory
we talked earlier about the iau's
reclassifications in 2006
but what actually was it that prompted
the debate between what constitutes a
planet or not
it wasn't pluto itself because pluto was
accepted as a planet for a long time
it was actually a series of minor planet
discoveries between 2003
and 2005 that were what got people
questioning the definition
these discoveries were made by mike
brown at palomar observatory
and in the years leading up to the iau's
decision in 2006
he identified three new dwarf planets
lurking beyond the orbit of pluto in the
kuiper belt
these worlds were eris haumea
and makimaki at present
none of these worlds have been visited
and so these far-out images are as close
as we've managed to get
however we have been able to deduce and
ascertain some of their properties by
using techniques
such as spectral analysis of these three
newfound dwarf planets it was eris that
caused the stir
eris is the second largest dwarf planet
in the solar system after pluto
but it is also the most massive it is
estimated to be about 2
320 kilometers in diameter
only about 50 kilometers less than the
dwarf planet's sibling
and so virtually the same size when
viewed on a global scale
scientists think that it is probably
rocky and icy with the terrain similar
to the one found on pluto
it was first spotted by brown in 2003
and was later confirmed in 2005
and when it was it was set to be
classified as the solar system's 10th
planet however this raised an
interesting dilemma
if we allow pluto eris and any other
dwarf planets to be
planets then before long the solar
system would have 20 or 30 planets
the vast majority of which would just be
rounded kuiper belt objects
and so this led to the addition of the
third criterium in the iau's definition
of a planet
effectively excluding all kuiper belt
objects from consideration both pluto
and eris were classified as dwarf
planets
and eris was named after the greek
goddess of strife and discord
we don't know much about what its
surface is actually like
purely because it is so far away is over
three times further away than pluto
and its orbit takes it far beyond the
kuiper belt to the cusp of interstellar
space at almost
100 astronomical units away
because it is so far away from the sun
gases like nitrogen and methane will
have almost certainly frozen down onto
its surface like they do on pluto
so perhaps the two worlds are more
similar than we yet realize
one thing we do know for certain though
is that eris has one small moon
named dysnomia it has a nearly circular
orbit around eris
completing a lap of the dwarf planet
once every 16 days
this satellite has allowed us to make
estimations of the dwarf planet's mass
which is how we managed to conclude that
it is more massive than pluto
and thus the most massive dwarf planet
in the solar system
but unfortunately that's about it and it
will probably be a while before we can
get any closer
as this world is so far away and remote
that
at present is simply too far beyond our
reach to study up close
[Music]
the second dwarf planet discovered by
brown was haumea
it was first noted in late december of
2004
originally being nicknamed santa before
being officially named after the
hawaiian goddess of fertility and
childbirth
it is about a third as massive as pluto
and it's hard to know whether to class
it as a dwarf planet or a small solar
system body
unlike the others mentioned so far it is
not a spherical world
instead it has an elongated egg shape
estimated to be around 1 600 kilometers
in diameter
its rapid rotation and high albedo are
clues as to its origins
and we now believe that the minor planet
is perhaps the largest constituent of a
collection of trans-neptunian objects
left over from a large collision of
debris
before this haumea was perhaps a rounded
world more analogous to pluto and
eris but this collision is thought to
have blown off haumea's icy mantle
resulting in a relatively unstructured
and unshapely body
composed of silica rock we cannot make
out the surface in much detail
but its colour changes as it rotates
relative to us
indicating that there is a dark patch on
its surface like on pluto
it also has two very small moons hiyaka
and namaka which are also thought to be
remnants of the same collision
perhaps its most unusual and captivating
feature
is that it has a faint ring around it
making it the first trans-neptunian
object with a ring system to be
discovered
the ring's width is about 70 kilometers
and it extends the system's total
diameter to around 2
300 kilometers wide pretty impressive
complexity for such a small
immature world
[Music]
finally we have makimaki the third dwarf
planet to be discovered by brown
in 2005. it is slightly smaller than
haumea
about 1 400 kilometers in diameter
but unlike the former it is rounded by
its own gravity
while small it is the brightest
trans-neptunian object after pluto
but it managed to evade detection for
many years thanks to its unusual orbit
which lies out of sync with the solar
system's ecliptic plane
at this moment in time it is over 50
astronomical units away
near the outer edge of the kuiper belt
which is about as far away from the sun
as it gets along its journey
analysis of its spectral data revealed
that its surface is most likely covered
in grains of frozen methane
there is also evidence for small
quantities of nitrogen ice
but nowhere near as much as on pluto
indicating that it has lost its nitrogen
over time
the presence of methane and nitrogen
together suggests that the world may
have a transient atmosphere like pluto
if so this would explain the nitrogen
depletion
because makimaki is particularly small
it cannot retain
its atmosphere when it expands
especially the nitrogen
methane is lighter than nitrogen but it
freezes at much higher temperatures
meaning much less methane thaws when
exposed to the sun
nitrogen on the other hand is easily
excited by the sun's light
and only the difference of a few degrees
causes it to sublimate into a gas
where it is lost to space thanks to the
low escape velocity of the dwarf
makimaki also has a tiny moon nicknamed
mk2
like the others it is thought to have
formed from a collision
but unlike its parent its body is as
dark as charcoal
perhaps because it is simply too small
to have been able to retain
its reflective ices which sublimated and
escaped into space
long ago along with makimaki's nitrogen
[Music]
ice
i don't plan on doing a christmas video
this year but because it's december
here's a christmas themed minor planet
arakoth is a small solar system body
about a billion and a half kilometers
further from the sun than pluto
it was discovered in 2014 using the
hubble telescope
at a time when the new horizons team
were looking for one final body for the
spacecraft to visit
following the completion of the pluto
mission the year after arakoth isn't
anything special
or at least it seemed like it back then
and it was thought to be nothing more
than a large asteroid
but it was selected for the new horizons
flyby because
it was the closest and easiest object
for the spacecraft
to reach given its trajectory and fuel
constraints
as such aracoth is both the smallest and
most primitive object
ever studied up close by a flyby however
when the probe arrived it found
something totally unexpected
arakoth is double lobed meaning it has
two rounded segments which are connected
and one happens to be larger than the
other and so it appears like a snowman
albeit a very flat one we're not sure
how arakoth came to be like this
but the two segments probably formed
independently nearby to one another
before being pulled into orbit around
each other eventually connecting and
then gently merging
what we do know is that the body is very
red redder than pluto
and in fact it is the reddest body in
the outer solar system discovered to
date
this redness occurs over time when the
surface minerals of a body are zapped by
cosmic radiation and ultraviolet light
from the sun
indicating that it is both ancient and
well preserved in its primordial form
its composition differs wildly to most
objects explored prior with scientists
finding evidence of methanol water ice
and even
organic molecules from the data
in any case arikoff is by far the oldest
and loneliest snowman in the entire
solar system
as it takes its solitary 293 year
periodic orbit around the sun
dwarf planets are truly remarkable
little worlds
who would have thought that such complex
processes temporary atmospheres
ring systems and even tectonic activity
would be playing out so incomprehensibly
far away from the warmth of the sun
we certainly didn't expect it before we
reached pluto
and as is usually the case with space
exploration
what we found when we arrived completely
blew our ideas out of the water
and with nearly 800 000 small solar
system bodies out there
just imagine what else could be hidden
in the recesses of the kuiper belt
contemplating such ideas makes you
realize just how vast
detailed and intricate the solar system
really is
and that's just our star system imagine
what else could exist in the galaxy if
ours is anything to go by
then dwarf planets probably vastly
outnumber the planets of the galaxy
and they are more resilient and complex
worlds than we ever thought possible
you
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