The 14 moons of Neptune
are a strange bunch.
Most of them are small
potato shaped pieces of ice and rock.
Some are so far away from Neptune that
they need 29 years to circle Neptune once.
Almost all of them are asteroids
trapped by Neptune's gravity.
99.5% of all the mass around Neptune
is concentrated in Triton.
It's the 7th biggest moon, and
more massive than all other known moons
in the solar system that are
smaller than itself combined.
Its surface area is about as big as the
mainland of Russia and Australia together.
Also, Triton is one of only four objects
in the solar system that we know is geologically active.
Triton orbits Neptune in the 'wrong' direction,
against the rotation of Neptune,
which is unique in our solar system
for an object as big as Triton.
We can conclude from this that
Triton hasn't always been a moon of Neptune,
but probably was a dwarf planet that
was forced into submission by Neptune,
when the solar system was younger
and more chaotic.
The most popular theory here is that
Triton was once part of a double system,
when Neptune migrated
to the outer edges of the solar system,
its gravity interfered with the double system
and catapulted the other object into space,
while Triton was forced into orbit.
This would of disrupted the orbits
of other Neptune moons rather violently
and would most likely have
either pushed them away from Neptune,
or let them collide or crash into Neptune.
This would explain why Neptune's moons
are so dominated by Triton.
But, this will end one day,
Triton is being slowed down by Neptune,
and eventually,
it will either crash into it,
or be ground by Neptune's gravity into
a huge ring system, similar to Saturn's.
So, don't by real estate on Triton.
Fixed English Subtiles by
Mads Hagemann Nielsen - 2015