At the farthest reaches of the solar system lie the ice giants Uranus and Neptune.
Their calm looking blue atmospheres, huge ominous storms, delicate sets of encircling
rings, and moons with icy terrain hold many unsolved mysteries.
NASA’s Voyager 2 is the only spacecraft to have visited these two planets in the 1980s,
but the visits were very short.
But now scientists have learned some really amazing things about both these planets, and
something is probably happening on their surface that you won’t believe!
There’s four gas giants out there in our solar system.
But unlike Jupiter and Saturn, Uranus and Neptune are rich in water.
Most of that water is in the form of ice, and now new studies found there may also be
oceans under their icy layers.
But that’s not all.
Researchers now say these oceans could be rich in magnesium.
But these oceans...might be made of something else entirely!
And we’ll get to that soon.
We need to mention that even though Uranus and Neptune are considered gas planets, they
are also called ice giants because of their rocky, icy cores which are much larger than
the amount of gas they hold.
But some strange things have been discovered lately, and researchers have been trying to
figure out what is happening on the surface of these two ice giants.
Not only that, but some have wondered what it might be like if you tried to land on any
so-called ‘surface’ of Neptune and Uranus.
You may have also heard that it could actually rain diamonds on these planets.
And now some researchers believe that both Uranus and Neptune could have oceans of liquid
diamonds.
Now that sounds wild!
But how is this possible?
Keep that in mind, because we’re going to get to that in a couple of minutes.
But first, let’s take a look at each of these planets, and we’ll tell you the most
incredible things that have been discovered up to now.
You have to admit that Uranus is a bit of a sad and lonely world.
One that is tired of being the butt of many bad jokes, including that one.
However, its name is actually a reference to the Greek God of the sky.
This freezing world was the first planet ever discovered using a telescope in 1781 by William
Herschel, and is about 2.9 billion kilometers [1.8 billion miles] from the Sun.
Voyager 2 got as close as 80,000 kilometers [50,000 miles] from the planet, and captured
only a handful of images.
But those images had astronomers thinking it's possible that something really big crashed
into Uranus in the early days of the solar system, not once, but twice!
The result of these two big impacts left the planet rotating on its side.
This means it is orbiting the sun like a rolling ball, which, by the way, takes 84 Earth years
to go around once.
Uranus has 27 moons, and they could have formed from these big collisions that put the planet
on its side.
Also, its magnetic north and south are way different from its polar north and south.
Because of this, there are some really bizarre seasonal effects.
Imagine a planet that has its south pole pointing at the Sun, while the North pole is shrouded
in complete darkness for 21 years!
In 2011, telescopes showed something strange happening on the planet: a big fuzzy white
spot appeared on its frigid blue cloud tops, and astronomers claimed it was a giant methane
storm.
In fact, some of these storms have been spotted by the Hubble Telescope; huge storms half
or more the size of the entire USA!
The average temperature in the methane and ammonia clouds is -192.8°Celsius [-315 Fahrenheit].
Winds on the planet can reach up to 144 kilometers per hour.
[360 mph]
And by the way, Saturn isn’t the only planet in the solar system to have rings around it.
Uranus has two sets of rings both orbiting above its equator.
But its icy twin Neptune is even farther away from the Sun, some 4.5 billion kilometers
away!
[2.8 billion miles] and it takes 165 years to orbit the Sun.
Voyager 2 was able to get as close as 4,828 kilometers [3,000 miles] to Neptune, which
appears to be made up mostly of ‘ices’ and rock, and could possibly have a rock-ice
core about 1.2 times the size of the Earth, and around 10 times the Earth’s mass.
Its atmosphere is made up of three-fourths hydrogen and one-fourth helium with a small
amount of methane that produces clouds.
The bluish color of the planet is from light scattering and red wavelength absorption by
the methane in its atmosphere.
Like Jupiter’s giant iconic red eye, Neptune also has a huge dark vortex; an anticyclonic
storm called the ‘Great Dark Spot’ that is 11,000 kilometers across, almost as big
as the Earth, and it’s racing across Neptune at 1,100 kilometers per hour [700 miles per
hour] But that’s not all.
In fact, Neptune has the most ferocious and fastest planetary winds in the entire Solar
System reaching 2,000 kilometer per hour [1,200 miles per hour].
Definitely no place for a holiday.
The energy for those high speed winds is not coming from the Sun, but what might actually
be happening closer to the core of the planet.
In fact, Neptune appears to have some kind of internal heat source and radiates twice
as much energy as it gets from the Sun.
And even though it’s farther away from the Sun than Uranus, it’s a bit warmer thanks
to Neptune’s atmosphere which is probably holding in heat from its hot core.
Now, both of these planets have unstable and strange magnetic fields that are strongly
tilted relative to each planet's rotation axis, and are significantly offset from the
physical center of each planet.
It’s been a long mystery for some time now, and no one is sure why these magnetic fields
act so strange.
The magnetic field on Neptune is 27 times more powerful than that of the Earth, while
Uranus only has a magnetic field 1/3rd as strong as the Earth.
And we’ll explain in a minute what scientists think is causing the magnetic fields to act
strange...
Even though it might seem really cold on both these worlds, and the magnetic fields are
bizarre, intense heat and pressure thousands of kilometers below the surface of each planet
may tell a different story.
The atmospheres of both planets are primarily made up of hydrogen and helium with small
amounts of methane.
Below these atmospheric layers is a superhot, superdense fluid of ‘icy’ materials like
water, methane, and ammonia that wrap around the planet's core.
Because of this, astronomers studying these two ice giants have come to the conclusion
that it could be raining diamonds closer to the surface of each planet.
This is possible because deep inside both these ice giants, pressure and heat builds
until gaseous hydrogen turns into liquid metallic hydrogen.
Methane in the atmosphere decomposes, and as the bonds holding methane’s four hydrogen
atoms dissolve, the carbon atoms left over bind to one another under extreme pressure
to form diamonds.
At its core, Neptune reaches temperatures of up to 7273 Kelvin [7000 °C; 12632 °F]
which is comparable to the Sun!
While the core of Uranus heats up to 9,000 degrees Fahrenheit [4,982 degrees Celsius].
Yes, it could actually be raining diamonds closer to each planet's core.
But not only that, it is also possible that there are oceans of liquid diamonds beneath
the surface of the two ice giants.
Research was done by taking detailed measurements of the melting point of diamond.
When diamond is melted, it behaves like water during freezing and melting with solid forms
floating atop liquid forms.
Obviously, diamond is a very hard material making it really hard to melt.
And measuring the melting point of a diamond is also very difficult because when it’s
heated to very high temperatures, diamond changes to graphite.
But it’s diamond that turns into a liquid, not graphite.
So what scientists did to get around this problem is expose the diamond to extremely
high pressures by blasting it with lasers.
Diamond is liquefied at pressures 40 million times greater than found at Earth’s sea
level.
When the pressure is lowered to 11 million times greater than Earth’s sea level, chunks
of diamond start to appear.
But something happened that scientists didn’t expect.
The chunks of diamond didn’t sink, but floated on top of the liquid diamond layer creating
diamond icebergs.
These are the same ultrahigh temperatures and ultrahigh pressures found on both Uranus
and Neptune.
Both planets are estimated to be made up of 10% carbon.
So a large ocean of liquid diamond could deflect or tilt the magnetic field out of alignment
with the rotation of the planet...which could explain the strange magnetic field behavior.
Is it possible that both planets rain diamonds and have vast oceans of liquid diamond?
Only by sending a spacecraft there will we find out.
Now researchers and scientists are trying to get NASA to send a spacecraft to these
two worlds in order to study them.
But the planets will be closest to the Earth soon, and astronomers say that a spacecraft
would need to be launched by 2030 in order to take advantage of Jupiter's gravity, and
slingshot the spacecraft towards these ice giants to arrive in the mid 2040s.
In April 2021, astronomers spotted x-rays coming from Uranus using the Chandra X-ray
observatory.
This revealed some unknown dimension of the colorful ice planet.
This means that x-ray emissions have been detected on every planet in our solar system
now, except for Neptune.
In case you’re wondering, there are three ways a planet can produce x-rays; fluorescence,
scattering of solar x-rays, and emissions from auroras.
Uranus is scattering the sun's x-rays, and x-rays are also being created by energetic
electrons or protons which collide with the rings causing them to glow in x-rays.
It’s pretty much the same thing that causes Earth’s beautiful and amazing auroras.
We may soon know a lot more about these two mysterious planets in the future.
So make sure to stay tuned here to stay up to date.
Thanks for watching.