[narrator] Uranus and Neptune.
Two of the largest,
farthest
and strangest planets in our solar system.
[Phil Plait] Of all the big planets,
Uranus and Neptune remain the biggest enigmas.
[narrator] Today, astronomers are finally unlocking
why these supersized snowballs are so weird.
[Grant Tremblay] In Uranus and Neptune, we have two planets
that just don't like playing by the rules.
[narrator] Can an ancient mega-collision
reveal what knocked Uranus onto its side?
Can a missing twin world
unlock why one of Neptune's moons orbits the wrong way?
[Hakeem Oluseyi] This is a large moon
but yet it's orbiting the planet backwards.
That's a mystery that needs explaining.
[narrator] And what is the energy that drives the fastest winds
in the solar system?
It's a rare planet that has winds faster than the speed of sound.
[narrator] To find out, we venture to these frozen planets
explore their alien underworlds
to reveal what makes these ice giants
the weirdest worlds in the solar system.
[narrator] At the limits of our solar system lie two huge planets.
Uranus
and Neptune.
Both are over 14 times the mass of Earth.
They orbit more than 2.8 billion miles away from the Sun.
This makes them the farthest out, confirmed planets in the solar system.
And the most mysterious.
We have sent orbiters
to every major planet in the solar system
except Uranus and Neptune.
Uranus and Neptune are really far away
and sending a space probe out there is pretty hard.
[beeping]
[narrator] Only one NASA mission
has ventured out for a closer look.
Voyager 2 flies past Uranus in 1986
and Neptune in 1989.
The spacecraft reveals that these planets,
sculpted from frozen water, methane and ammonium,
are far from dead.
[Michelle Thaller] The thing that's so poignant about the ice giant worlds,
is that we've only visited them
for a couple of days.
The Voyager spacecraft just flew on by.
And yet, in that brief encounter,
we saw things we never expected.
Instead of cold, boring worlds
like we maybe thought they would be,
they were exciting. They had weather.
They turned out to be much more dynamic than we ever imagined.
[beeping]
[narrator] As Voyager 2 flies by,
it captures detailed photographs,
of the strange moons that orbit the ice giants.
Uranus has 27 moons.
Neptune has 14.
[Tremblay] The ice giants have
some of the most fascinating moons in the solar system.
You have Naiad and Thalassa,
two moons of Neptune that are locked
in this gravitational dance with one another.
And they zig-zag up and down
unlike any other moons in the solar system.
[Thaller] Uranus has Miranda,
this moon that seems to have been cracked apart and reassembled,
with vast craters and giant cliffs and fields of ice.
[narrator] The weirdest moon of all is Triton.
Triton is around half the size of Earth's moon.
But it is 400 times more massive than Neptune's next largest moon, Proteus.
[narrator] Two-thirds of Triton is rock and metal.
The rest is a crust of water and nitrogen ice,
frozen to a temperature of minus 390 degrees Fahrenheit.
This ice world is unlike any other large moon in the solar system.
[Tremblay] Triton is really unique
in that it's the only large moon in the solar system
with a retrograde orbit.
That's an orbit that is opposite to the direction of the planet's spin.
[narrator] Scientists think that most planets and their moons
form from the same spinning cloud of gas and dust.
The center of the spinning cloud
collapses to form a rotating planet
while the outer edge condenses into the planet's moons.
Everything turns in the same direction
as the original cloud.
So, how does Triton end up orbiting Neptune in reverse?
Today, new technologies and discoveries
make it possible to finally unlock
the mysteries of the ice giants.
A clue about Triton's strange orbit
lies in the data collected by one of NASA's most ambitious missions
to the outer solar system.
In 2015,
NASA's New Horizons probe flies past Pluto.
Pluto is a dwarf planet.
It is the largest object in the Kuiper belt,
a massive ring of billions of space rocks
that lies beyond the orbit of Neptune,
on the fringes of the solar system.
New Horizons beams back to Earth
breathtaking images of this frozen world.
Pluto just blew me away.
We saw glaciers made of nitrogen ice.
And one of my favorite images from the past decade
is sunlight glinting off of mountains of pure water ice.
[narrator] The scientific instruments on board the probe
analyzed Pluto's vital statistics
to unlock what the dwarf planet is made from.
The instruments revealed
that Pluto and Triton are almost exactly the same.
The bodies are roughly the same size.
Both Pluto and Triton have cores made from rock and metal.
And their crusts consist of layers of frozen nitrogen, water and methane.
This evidence points to an incredible possibility.
One that could solve the mystery
of why Triton orbits Neptune backwards.
[Tremblay] Triton and Pluto
are in many ways geological twins.
One of the simplest explanations that could account for that
is that they originated from the same place.
[narrator] That place is the Kuiper Belt.
Why did Triton break out
from this ring of rocks?
Astronomers think that Neptune's size
could reveal the answer.
Neptune is 17 times more massive than Earth.
This mass gives the planet
a super-strong gravitational influence.
It is possible that over time
Neptune's huge gravity
gradually pulls Triton away from this ring of rocks
to eventually capture it as its moon.
But there is one problem with this theory:
the speed of the objects inside the Kuiper Belt.
[Oluseyi] If you do the calculations what you will find is,
by the time a solitary Triton passes by Neptune,
it's moving too fast to be captured.
Neptune's gravity would have deflected it,
but it would have just kept on going.
In order for Triton to end up in orbit around Neptune,
something would have had to hit the brakes and slowed it down.
[narrator] What slowed down Triton enough
for Neptune to capture it?
And how did this dwarf planet
end up orbiting Neptune backwards?
[narrator] The giant ice planet, Neptune,
has a weird moon.
Triton orbits in the opposite direction
to Neptune's rotation.
One explanation is that
the planet pulled Triton from the Kuiper Belt.
But what slowed down Triton enough
to allow Neptune to capture it
travelling the wrong way?
Astronomers believe that one of Pluto's moons
offers a clue.
Charon is half the size of Pluto.
This closeness in size
makes the pair dance around each other
as they orbit the sun.
[Oluseyi] Pluto is not much bigger
like all the other planets and moons.
So instead of being like, a single large body
with a smaller one orbiting it,
it's more like a dumbbell,
and this dumbbell orbits as one thing.
[narrator] Astronomers call two orbiting bodies of a similar size
a binary system.
The strange orbit of binaries
could unlock how Triton slows down enough
for Neptune to capture it travelling the wrong way.
When objects in the Kuiper Belt pick up a partner,
they completely change the way they move
through the cosmos.
Once they've caught each other,
they start revolving around their common center of gravity.
This disrupts their trajectory,
as on every turn,
one partner must move backwards
against their orbit.
Once every pirouette,
they can slow down so much
that they become vulnerable to capture.
Some astronomers believe that
Triton once had its own binary partner,
just like Pluto has Charon today.
They think that this missing binary
is the key that unlocks how Neptune captures Triton.
[Plait] The discovery that
ten to fifteen percent of Kuiper Belt objects are binary
may solve the Triton problem.
If Triton itself was a binary,
it had a large companion
when it passed by Neptune.
That could have put the brakes on it
and allowed it to orbit Neptune.
[narrator] Triton and its companion
orbit each other inside the Kuiper Belt.
Over time,
Neptune's gravity gradually pulls
the pair away from the Belt.
They fall towards the giant planet
and slingshot around it.
Thanks to their binary dance,
there is a point when Triton moves slowly enough
for Neptune to capture it.
This breaks the gravitational bond
between Triton and its partner
and hurls its companion across the solar system.
Triton is left alone
orbiting Neptune the wrong way.
This companion was kind of a sacrificial lamb
that got kicked out into the depths of space
in order for Triton itself to be captured into Neptune's orbit.
[narrator] Triton's strange orbit
is just one of this weird moon's mysteries.
Voyager 2
photographs Triton up-close in 1989.
The camera on board captures something weird
on the surface of this strange world.
Hidden in this grainy photograph
is a mysterious plume
that rises from the surface of Triton.
The plume is a geyser of frozen nitrogen
five miles high.
Winds in the moon's thin upper atmosphere
blow the vapor into trails
that are hundreds of miles long.
When Voyager flew past Triton,
it saw the unexpected.
There were jets of gas shooting out from the moon's surface.
No one expected that.
It's out at the far reaches of the solar system.
We expected to find a cold, dead moon.
What the heck is going on?
[narrator] Why do geysers blast from the surface of Triton?
And what is the power source that drives them?
In 2019,
investigators used the Gemini South telescope in Chile
to study Triton's icy crust.
Researchers discovered that
the ice on the surface of Triton
is a special cocktail
of carbon monoxide and frozen nitrogen.
[Thaller] In some ways you can think of Triton
as having a frozen atmosphere.
Our atmosphere on Earth is mostly nitrogen
and that's true on Triton too.
But the nitrogen's frozen into a layer of ice.
That ice is actually transparent to light.
So, sunlight can get through that transparent ice
and heat up little pockets in it.
[narrator] Some types of ice
transform directly from a solid into gas,
when they heat up inside an atmosphere
that is super thin.
Astronomers believe that this volatility of Triton's ice
unlocks they mystery of its mega geysers.
At a point in Neptune's year,
Triton's north pole leans towards the Sun.
This gives one hemisphere of the moon
a summer that lasts 41 Earth years.
The rays from the Sun are weak
but they can pass through Triton's nitrogen ice.
Here, they hit a dark layer of dust
which heats up by just a few degrees.
Enough to turn the ice above into gas.
[ice cracks]
The pressure rises as the gas builds up,
until it erupts as powerful geysers of nitrogen.
[faint beeping]
Voyager 2 shows that ice giants contain many secrets.
The data it beams back to Earth
reveals another mystery for astronomers to solve.
The magnetometer on board the probe
detects that the magnetic field of Uranus
is super strange.
The field lines continually twist and shift.
The magnetic poles are offset
from the planet's axis of rotation
by a massive 60 degrees.
Voyager 2 discovers later
that the magnetic field of Neptune
is also irregular and misaligned.
When you think about the magnetic of a planet,
sometimes you get something very simple, like the Earth.
It's almost as if there's a giant bar magnet
going right through the core of our planet
with a very clear north pole and south pole.
With the ice giant,
something altogether different is going on.
The magnetic fields are chaotic.
The magnetic field lines twist and turn
like a bag of writing snakes.
And the south pole of the planet
is actually along the equator.
[narrator] Why are the magnetic fields of the ice giants twisted?
Can a strange material deep inside Uranus
unlock the mystery?
[narrator] Uranus and Neptune
lie at the farthest reaches of our solar system.
Voyager 2 remains the only mission
to visit these ice giant planets.
The spacecraft discovers that they have strange moons
and bizarre, twisted magnetic fields.
Why are the magnetic fields of Uranus and Neptune so chaotic?
Scientists believe the answer lies
in discovering what inside the ice giants
generates their magnetic fields?
A mass of molten iron and nickel
sits at the center of a rocky planet like Earth.
This super dense liquid metal
forms a thick and compact shell
wrapped around the planet's core.
Heat drives powerful currents inside this concentration
of molten material.
These deep currents generate a magnetic field.
The rotation of Earth twists the currents
into orderly streams that move in the same direction
as Earth turns.
The result is that the axis of Earth's magnetic field
almost matches the axis of the planet's rotation.
Well, the magnetic field is generated
by rotating liquids inside the planet
and those liquids are going to rotate
along with the planet itself.
So, it makes sense that
the planet's geographic north and south pole
align with the magnetic north and south pole.
However, with Uranus, we don't see that.
[narrator] An ice giant contains no moving metal
at its core.
Scientists believe the cores of these planets
are made from a mixture of
rock, water, methane and ammonia.
So, what happens at the center of ice giants?
Scientists at the University of Rochester in New York
believe that the huge pressure at the core of ice giants
helps unlock the mystery.
[beeping]
In 2018,
they test how this pressure transforms water
into weird states of matter with strange properties.
They use an anvil made of diamonds
to compress a sample of water
to a pressure similar to that at the core of an ice giant.
The crust water transforms at the molecular level
and turns into a super-hot jet black material
called superionic ice.
Its oxygen atoms form a rigid lattice
that hydrogen atoms can float through,
meaning that it can become electrically charged.
But this weird ice is rigid.
So if it is at the core of the ice giants
it creates a fundamental problem.
Only moving material inside a planet
can act like a dynamo and generate a magnetic field.
The Rochester experiment
shows that an ice giant's core could be static.
This means that the planet's magnetic field
can't come from there.
Water ice under the right conditions
very compressed to the core of a planet
is actually stopping the magnetic field
going through the very center of the planet.
So there's gonna be no magnetic field
based in the core of Uranus.
[narrator] If the super pressurized
ice core of an ice giant
doesn't generate the planet's magnetic field,
then what does?
One theory is that a liquid ocean of compressed water
exists in a thin shell
around the solid core of an ice giant.
[Thaller] Farther up from the core,
there's this sort of a Goldilocks Zone.
Not too compressed, the water can flow around
yet still be electrically charged,
and there's your magnetic field.
[narrator] How this layer of pressurized liquid
moves around this solid superionic ice core,
could unlock why the magnetic fields
of ice giants are chaotic.
Deep inside Uranus...
[rumbling]
...lies a compressed superionic ice core
that is a scorching 9,000 degrees Fahrenheit.
Somewhere in between this rigid ball
and the surface of the planet
is a shell of highly pressurized water that can flow.
But the disconnected currents inside this layer
do not generate a magnetic field that matches
the direction of the planet's rotation.
So that's how the magnetic fields of the ice giants
can slip and become misaligned.
Weird water unlocks why the ice giants
have super strange magnetic fields.
But these mega planets contain more mysteries
for astronomers to solve.
[beeping]
Voyager 2 sees up close, arguably, the single strangest characteristic
of either of these distant planets.
[Plait] There's a lot of weird stuff about Uranus
but maybe the weirdest is that it orbits the Sun on its side.
[narrator] Uranus leans over 98 degrees from the vertical.
It is the only planet in the solar system
that is orientated this way.
Why does this ice giant roll around the Sun
like a huge beach ball?
Astronomers think that planets form
from a disc of gas and dust...
orbiting a young star.
These young worlds inherit both their direction and axes of spin
from the angle of the disc.
This means that all of the planets
should be born with a spin axis
that is roughly 90 degrees to the disc.
This model predicts that Uranus starts life upright,
just like all the other planets in the solar system.
So what tips Uranus onto its side after it forms?
Scientists believe that a clue lies in our solar system's violent past.
[loud crashing]
The early days of the solar system
were a chaotic maelstrom of smash-and-grabs.
We see evidence of this, of course, in the form of craters
on many bodies in the solar system.
[narrator] Does an ancient mega-collision knock Uranus onto its side?
And what are the mysterious spots in the atmosphere of Neptune?
[narrator] Uranus leans over so much that it orbits the Sun on its side.
One explanation is that Uranus is involved
in a mega-collision billions of years ago.
But what kind of cosmic crash
can knock over an entire planet?
Researchers at the University of Durham in the United Kingdom
simulate impacts between Uranus and large protoplanets.
They build a virtual Uranus
and fire space objects at it from different angles.
These simulations show that a head-on collision
blows apart the virtual Uranus.
But a sideswipe generates just the right amount of force
to leave Uranus spinning on its side
without destroying the ice giant.
Around four billion years ago,
icy protoplanets surround a young Uranus.
One ice ball planet, twice the size of Earth, wanders too close.
The ice giant's immense gravity
locks the planet into a collision course.
The impact knocks Uranus backwards
The smaller planet disintegrates in a shower
of water and methane ice.
The crash leaves Uranus tilted over permanently.
The icy debris comes together over time
to form the ice giant's 27 moons,
and a spectacular ring system, similar to the one around Saturn.
When you think about this violent destructive collision
that tilted the whole world on its side,
there was also a creative flipside to it, as well.
It generated a whole new system of moons and rings.
[beeping]
[narrator] Voyager 2 arrives at Neptune in 1989.
Here it uncovers another ice giant enigma.
The spacecraft captures this image of a mysterious cyclone
in Neptune's southern hemisphere.
It is almost 8,000 miles wide.
[Thaller] There was a beautiful surprise waiting for us
when Voyager finally got out to Neptune.
There was a giant storm churning away in the atmosphere.
This storm was about the size of the Earth
and we called it the Dark Spot.
[narrator] The instruments on board Voyager 2
measured the wind speed inside this mega-storm
to be in excess of 1,500 miles per hour.
The winds are moving so fast,
they're moving twice the speed of a commercial airliner.
[Plait] When you look at pictures of Uranus and Neptune,
they're just kinda green and just kinda blue.
But, in fact, these atmospheres are incredibly dynamic
with enormous storms erupting all the time.
[Thaller] The very workings of Neptune's atmosphere are very mysterious.
How do you form a huge Earth-size storm
and winds that blow that fast at that cold temperature?
[narrator] The Sun powers the weather on Earth.
Its radiation heats the surface of our planet.
This heat creates currents in the atmosphere
that move to make wind.
Neptune is almost three billion miles away from the Sun.
The energy that Neptune receives from this star
is too weak to drive its weather in the same way as on Earth.
So where does the massive energy that drives these storms come from?
The Hubble Space Telescope finds a clue
almost 30 years after Voyager 2
discovers the Great Dark Spot.
In 2018,
the telescope captures this image of a new dark spot.
This one is in the planet's northern hemisphere.
[Thaller] The amazing thing about Neptune
is how dynamic it is.
We see evidence of new dark spots forming.
So this world is very much alive.
It may be cold, but it's not dead.
[narrator] Astronomers scour other images of Neptune taken by Hubble
for clues that can unlock the genesis of this new spot.
Hubble photographs the surface of the ice giants every year.
It creates these rolled out two-dimensional images of the surface of Neptune.
Astronomers use these images to monitor changes in Neptune's atmosphere.
They see something unusual in this photograph from 2017.
Mysterious clouds of methane cover the area
where Hubble sees the dark spot a year later.
[Plait] On Earth, storms form when warm air rises carrying water vapor with it
and that forms bright clouds.
Well, we think a similar thing is happening on Neptune.
Methane is coming up through the atmosphere,
rises up and cools and forms these bright white clouds we see on Neptune,
right before the big storm erupts.
[narrator] These clouds are evidence that it is an energy source
inside Neptune that drives the dark spot storms.
What is this mysterious source of energy?
And how does it generate the fastest winds in the solar system?
[narrator] The storm winds on Neptune
exceed 1500 miles per hour.
But how can a giant planet made of ice,
far away from the Sun,
have the energy to drive these mega-hurricanes?
The very large telescope in Chile takes infrared images of Neptune
to reveal its temperature.
This heat map shows that the upper atmosphere of Neptune
is -330 degrees Fahrenheit.
But this frozen ice world has a core temperature
of 12600 degrees Fahrenheit.
That is hotter than the surface of the Sun.
Neptune's high core temperature is the result of the planet's formation
billions of years ago.
The early solar system is a massive fast-moving disc of gas and dust.
Gravity collapses clouds of this gas into protoplanets.
The temperature inside a planet
rises as more material compresses to grow its mass.
[Tremblay] Neptune formed from the collapse of gas and dust under its own gravity.
And that collapse can lock in a lot of that internal energy
left over from the early days of the solar system
that can last within the planet for billions of years.
[narrator] Astronomers think that this difference in temperature
between Neptune's hot core and cold atmosphere
is what triggers the planet's superstorms.
The extreme heat that radiates from Neptune's core
vaporizes the frozen gas close to the planet's surface.
This forces methane gas
high into the coldest parts of the atmosphere,
where it crystalizes into wispy clouds.
The hot rising gas beneath finally erupts.
It punches a hole in the upper atmosphere
that appears as a Giant Dark Spot.
The extreme temperature difference between the gases
generates mega convection currents
that whip the spot into a supersonic vortex.
The driving force behind Neptune's mysterious mega winds
is not the final mystery the ice giants pose.
Uranus is 14 times more massive than Earth.
Neptune is a whopping 17 times more massive.
These huge worlds prowl the farthest reaches of the solar system
between 1.8 and 3 billion miles from the Sun.
This strange combination of supersize and distant position
presents a big puzzle for astronomers to solve.
[Oluseyi] One of the mysteries of Uranus and Neptune
is their location in the solar system.
They're so far away from the Sun
that there would not have been enough material
in the early solar system to build large planets of that size.
It shouldn't be possible for these guys to exist where they do.
But they do.
[narrator] The early solar system is a swirling disc of gas and dust.
When the Sun ignites, its heat blows away the lighter elements.
Over 400 million miles out,
it is cold enough for these elements to condense as gas and ice,
and settle in a band around the Sun.
This material binds together to form the beginnings of Jupiter and Saturn.
These planets grow larger as they absorb more and more gas and dust.
But where Neptune and Uranus orbit,
the raw materials to build giant planets
are in much shorter supply.
So how is it possible for the ice giants to form this far out?
[Tremblay] To build a planet, especially a giant one,
we need countless tiny rocky and icy bodies
to come together, to grow over time.
And we think that where we see these planets nowadays,
in the far outskirts of our solar system,
this material was just too scarce
to grow planets that large.
[narrator] Astronomers arrive at an astonishing conclusion
to explain this anomaly.
The ice giants come from somewhere else in the solar system.
[Plait] One possible solution is that
Uranus and Neptune didn't form where they are now.
If they formed closer into the Sun,
there would have been enough material
to create such large planets.
And then somehow, Uranus and Neptune moved out to where they are today.
[narrator] Why did these ice giants migrate
to the farthest reaches of the solar system?
And what was the role of these planets in shaping the solar system we see today?
Astronomers think that Neptune and Uranus
were not born in the far reaches of the solar system,
where they are today.
Instead, they formed closer to the Sun
and then moved farther and farther out.
What triggered this epic migration of the ice giants?
Scientists believe the answer is locked inside meteorites.
Meteorites are the parts of ancient asteroids that collide with Earth.
They contain tiny quantities of radioactive elements.
These elements allow scientists to date the meteorites,
to discover the exact age of the asteroids they come from.
[Plait] Meteorites that fall to Earth
have elements like uranium, which is radioactive.
And this radioactive decay that uranium undergoes
is like a ticking clock
that allows us to get the age of the meteorite.
[narrator] The radioactive clock starts ticking
when the space rock first forms at the birth of the solar system.
That means all meteorites should be around 4.6 billion years old.
But scientists make an extraordinary discovery
when they date the space rocks that fall to Earth.
One that can unlock the mystery of why the ice giants
moved farther out across the solar system.
[Plait] When we get the ages of meteorites through radioactive decay,
we find that most of them are about the same age as the solar system itself.
However, a lot of meteorites have a significantly younger age.
[narrator] The clocks of these younger asteroids
start ticking around 80 million years after the solar system forms.
Super-heating and melting the minerals inside asteroids
resets their radioactive clocks.
Scientists believe that
only a super-violent solar system-wide catastrophe
could generate temperatures high enough
to melt down so much rock.
We're talking destruction
on a truly unprecedented scale.
Entire worlds colliding together and getting obliterated,
asteroids flying every which way you look.
If you were to actually look up in the sky during this time,
you'd have seen this destructive light show unlike any other.
[Plait] Objects were streaming around,
smashing into each other, and remelting.
And that's why these meteorites
seem to be younger than the solar system itself.
[narrator] Scientists think this disaster
impacts all the planets in the solar system...
including the ice giants.
But what triggers this mega violent event?
And how does it banish Uranus and Neptune
to a region of space billions of miles from the Sun?
Astronomers believed that the proximity of the ice giants
to their gas giant neighbors, Jupiter and Saturn,
unlocks the mystery.
[Thaller] Probably all four major worlds of our solar system,
Jupiter, Saturn, Uranus and Neptune
were competing for planet-building materials,
jockeying for position in a young solar system.
All of a sudden, you're kind of playing planetary pinball.
[narrator] Around 4.6 billion years ago,
Jupiter, Saturn, Neptune and Uranus
orbit much closer to each other than they do today.
Back then, their proximity causes gravitational chaos.
The huge gravity of the larger Jupiter and Saturn
forces out the smaller ice giants.
And they begin an epic journey across the solar system.
One theory is that they even swap places along the way.
Uranus and Neptune travel billions of miles
to end up in the sparse outer reaches of the solar system.
[Thaller] The truth of the matter is that
if you're jostling with Jupiter and Saturn for real estate,
even an ice giant
really doesn't stand much of a chance.
It's out to the suburbs.
[narrator] This gravitational battle
between Jupiter, Saturn and the ice giants
triggers an intense asteroid bombardment on the solar system.
Space rocks smash together in mega impacts
in the most violent period of the solar system's history.
This stress melts and reforms the asteroids,
and resets their radioactive clocks.
Over time, many of these rocks
drift into the inner solar system
and crashed to Earth as meteorites.
The migration of Uranus and Neptune
explains why the ice giants orbit so far from the Sun.
Their movement reshuffles the entire solar system.
And locks it into the configuration we know today.
The ice giants are the weirdest worlds in the solar system.
From Neptune's superfast winds...
and the giant geysers on its moon, Triton...
to the bizarre sideways rotation of Uranus...
and it's strange magnetic field
powered by an exotic form of water...
these two planets break all the rules.
Uranus and Neptune are dynamic, interesting,
and above all else, weird places.
[Thaller] The ice giants prove to us that
there's no such thing as a normal planet.
They work in an entirely different way
than any other type of planet that we know of.
[Oluseyi] They just completely blow away our ideas
of how planets are formed.
So far, we only had a glimpse of these ice giant planets.
And the next probes that go there,
might find they're even weirder
than we think now.
[narrator] Our solar system
would be a very different place,
if it were not for these strange oddball worlds.