Solar.System.2024.S01E05.1080p.BluRay.x264-DRCOX_track3_[eng] Subtitles

00:00:17,280 --> 00:00:21,We all know the familiar faces
of our solar system.

00:00:22,840 --> 00:00:24,The worlds we grew up with.

00:00:27,280 --> 00:00:29,But there's another side
to our solar system

00:00:30,80 --> 00:00:31,we're now discovering.

00:00:35,360 --> 00:00:38,The misfits and oddballs.

00:00:41,480 --> 00:00:44,Worlds of freakish shape
and size.

00:00:48,600 --> 00:00:50,Of extreme landscapes...

00:00:55,00 --> 00:00:56,.. mysterious phenomena...

00:01:02,200 --> 00:01:03,...and hidden secrets.

00:01:09,880 --> 00:01:14,Our neighbourhood is far
stranger than we ever imagined.

00:01:17,480 --> 00:01:20,So, how did
all these weird worlds

00:01:20,480 --> 00:01:22,come about?

00:01:25,80 --> 00:01:26,Well, to answer that question,

00:01:26,680 --> 00:01:29,we'll have to explore the force
that sculpted

00:01:29,920 --> 00:01:32,and created them - gravity -

00:01:32,320 --> 00:01:36,and the forces that resist
its relentless inward pull.

00:01:37,800 --> 00:01:40,And also, at a deeper level -

00:01:40,240 --> 00:01:42,cos there's always
a deeper level -

00:01:42,520 --> 00:01:44,we'll be forced to contemplate

00:01:44,600 --> 00:01:47,why there is
anything of complexity

00:01:47,360 --> 00:01:50,and beauty in our universe
at all.

00:01:50,160 --> 00:01:54,Welcome to the solar system
of the weird.

00:02:22,640 --> 00:02:25,From a cloud of gas and dust,

00:02:25,520 --> 00:02:29,gravity, the great sculptor
of our universe,

00:02:29,400 --> 00:02:31,fashioned our star
and all the worlds

00:02:31,920 --> 00:02:33,and moons around it...

00:02:40,520 --> 00:02:42,... creating the solar system.

00:02:55,00 --> 00:02:58,And gravity has continued
to shape these myriad worlds

00:02:58,720 --> 00:03:00,ever since.

00:03:09,80 --> 00:03:13,Let me give you a little
30-second lecture on gravity.

00:03:15,200 --> 00:03:16,And I'm going to use
Newton's picture,

00:03:17,00 --> 00:03:18,not Einstein's,
cos we don't need

00:03:18,560 --> 00:03:21,the additional accuracy
delivered by relativity.

00:03:23,280 --> 00:03:26,Gravity is a force
of attraction between objects -

00:03:26,600 --> 00:03:28,and it only attracts,

00:03:28,400 --> 00:03:31,so that means that it tends
to clump things together.

00:03:31,600 --> 00:03:35,And it's a force that only
depends on the distance

00:03:35,920 --> 00:03:38,between objects, not the angle,

00:03:38,320 --> 00:03:41,and so it tends
to make spheres.

00:03:44,600 --> 00:03:46,It's this property
of gravity...

00:03:52,480 --> 00:03:56,... that shaped the moons
and planets.

00:04:01,320 --> 00:04:03,But beyond
the near-perfect spheres

00:04:03,480 --> 00:04:05,that dominate
our solar system...

00:04:11,320 --> 00:04:13,...out past the giant orbs...

00:04:15,400 --> 00:04:19,...Of gas and ice...

00:04:22,520 --> 00:04:25,.../n a distant realm
of the solar system...

00:04:27,80 --> 00:04:30,...we found something strange.

00:04:46,240 --> 00:04:50,Only one craft has been sent
to explore the worlds

00:04:50,240 --> 00:04:52,of this distant region.

00:05:04,440 --> 00:05:07,And on its epic,
ongoing journey,

00:05:07,600 --> 00:05:10,the probe caught a glimpse
of something truly bizarre

00:05:11,00 --> 00:05:13,moving in the dark.

00:05:20,80 --> 00:05:23,Not a sphere like Earth,
or even Pluto...

00:05:25,960 --> 00:05:31,...but a giant,
2,000-km-long egg-shaped world.

00:05:39,240 --> 00:05:41,Orbiting around it,

00:05:41,200 --> 00:05:44,two glittering moons.

00:05:44,440 --> 00:05:49,Mountains of icy rock
and a faint ring.

00:05:51,440 --> 00:05:54,If you were standing
on Haumea's surface,

00:05:54,680 --> 00:05:57,the stars would wheel above you

00:05:57,120 --> 00:06:00,six times faster
than here on Earth.

00:06:03,800 --> 00:06:07,Haumea Is a truly unexpected
and bizarre-shaped object.

00:06:11,960 --> 00:06:14,The first like it
ever discovered.

00:06:22,560 --> 00:06:24,Leaving the question...

00:06:26,640 --> 00:06:28,...what created

00:06:28,320 --> 00:06:31,such a seemingly
gravity-defying world?

00:06:38,320 --> 00:06:39,Now, for rocky worlds,

00:06:40,80 --> 00:06:43,the force resisting
the inward pull of gravity

00:06:43,800 --> 00:06:46,is created by this -

00:06:46,320 --> 00:06:48,the rigidity of the rock.

00:06:49,00 --> 00:06:51,And the thing about pressure is

00:06:51,400 --> 00:06:56,that it acts equally outwards
in all directions,

00:06:56,360 --> 00:06:57,so if you have a force

00:06:57,720 --> 00:06:59,that's squashing
everything inwards equally

00:06:59,440 --> 00:07:01,in all directions,
and a force that's resisting

00:07:01,880 --> 00:07:05,that squashing equally
in all directions,

00:07:05,160 --> 00:07:09,then the shape that's naturally
produced is a sphere.

00:07:09,400 --> 00:07:10,And you might say,

00:07:10,680 --> 00:07:14,well, why is something
like that not a sphere, then?

00:07:14,520 --> 00:07:15,| mean, it's made of rock,

00:07:15,920 --> 00:07:17,it's g***t a gravitational pull,

00:07:17,960 --> 00:07:20,but it's a very weak
gravitational pull

00:07:20,240 --> 00:07:21,because it's not very massive.

00:07:21,880 --> 00:07:23,And that's the point.

00:07:23,680 --> 00:07:26,So the gravitational forces
on the surface here

00:07:27,00 --> 00:07:30,trying to squash it down
are nowhere near big enough

00:07:30,280 --> 00:07:33,to overcome
the strength of the rock.

00:07:35,280 --> 00:07:38,So, how big
does a thing have to be

00:07:38,360 --> 00:07:41,such that the gravitational
force is strong enough

00:07:41,400 --> 00:07:43,to overcome
the strength of the rock

00:07:43,760 --> 00:07:46,and allow it
to deform into a sphere?

00:07:46,720 --> 00:07:49,And you find, if you wave
your hands around a bit,

00:07:49,720 --> 00:07:53,that that size, the radius,
is something like

00:07:53,280 --> 00:07:56,200, 300km.

00:07:57,40 --> 00:07:58,It's called the potato radius.

00:07:58,960 --> 00:08:00,And indeed, you find that,

00:08:01,00 --> 00:08:02,if you look out
into the solar system,

00:08:03,80 --> 00:08:04,anything that's smaller

00:08:04,600 --> 00:08:07,than about a couple of hundred
kilometres in radius

00:08:07,360 --> 00:08:09,looks like that.

00:08:09,160 --> 00:08:10,And anything that's bigger

00:08:10,720 --> 00:08:12,than a couple of hundred
kilometres in radius

00:08:13,80 --> 00:08:15,looks like the Earth.

00:08:18,560 --> 00:08:23,From what we observe,
it seems that the potato radius

00:08:23,120 --> 00:08:25,is a pretty strictly followed
rule.

00:08:35,600 --> 00:08:37,The larger worlds are,

00:08:37,400 --> 00:08:39,the more spherical they become.

00:08:42,200 --> 00:08:46,Yet it's a rule Haumea breaks.

00:08:53,880 --> 00:08:56,Way over the potato radius,

00:08:56,440 --> 00:08:59,Haumea should be a round world.

00:09:00,720 --> 00:09:04,So, if its egg shape is not
down to its size,

00:09:04,520 --> 00:09:06,then what is it?

00:09:07,880 --> 00:09:09,There is a clue,

00:09:09,560 --> 00:09:14,found by looking at our world
in a Slightly unusual way.

00:09:16,800 --> 00:09:20,This is a photograph of us
working on the beach today.

00:09:20,560 --> 00:09:22,| use the term loosely.

00:09:22,640 --> 00:09:25,And what we did is
we took a time-lapse.

00:09:25,960 --> 00:09:27,But it's an interesting
time-lapse.

00:09:28,00 --> 00:09:29,We used an astronomical mount,

00:09:30,00 --> 00:09:34,and so we fixed the camera
at a single point in the sky -

00:09:34,920 --> 00:09:36,the sun.

00:09:36,360 --> 00:09:38,And then,
can you see what happens?

00:09:38,840 --> 00:09:40,So, it's holding its position.

00:09:40,840 --> 00:09:42,It doesn't look right

00:09:42,720 --> 00:09:46,because the whole ground is
rotating around.

00:09:47,440 --> 00:09:50,So, usually, our experience
on the surface of the Earth

00:09:50,480 --> 00:09:53,is watching the sky and the sun
and the moon and the stars

00:09:54,80 --> 00:09:56,rotate around us.

00:09:56,160 --> 00:09:58,But if you take that motion
out,

00:09:58,440 --> 00:10:00,then what you're seeing here
is the Earth

00:10:00,800 --> 00:10:03,rotating beneath the sky.

00:10:14,440 --> 00:10:17,This unusual view
really brings home the fact

00:10:18,80 --> 00:10:20,that we live on a spinning ball
of rock.

00:10:28,600 --> 00:10:32,And there are consequences
for sitting on the surface

00:10:32,280 --> 00:10:34,of something that's spinning.

00:10:34,400 --> 00:10:36,New forces are introduced,

00:10:36,800 --> 00:10:39,forces that are so-called
fictitious forces -

00:10:39,960 --> 00:10:41,but there's nothing fictitious
about them.

00:10:41,840 --> 00:10:43,Actually, you'll know that
if you've tried to hang on

00:10:43,920 --> 00:10:45,to a spinning roundabout.

00:10:45,320 --> 00:10:47,If you let go,
you go flying off.

00:10:47,760 --> 00:10:49,That's not a fiction.

00:10:49,200 --> 00:10:51,And that force is called
the centrifugal force.

00:10:55,80 --> 00:10:59,Like the Earth, all worlds
in...