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Ah! There you are.
Beautiful, isn't she? The Milky Way Galaxy.
And to think, each one of those hundred billion stars has it's own planets, it's own strange worlds.
Imagine what it would be like to visit some of those exoplanets beyond our own little solar system.
Well today, you don't have to imagine,
because I'm going to take you on a tour of six real exoplanets.
What you're about to see is based on the latest scientific research;
and as we travel across the cosmos, we'll hear astrophysicists from the University of Exeter
tell us about their search for planets beyond our solar system.
So, if you want to experience what it might be like to stand on another planet,
I highly recommend strapping on a VR headset and a pair of headphones to feel truly immersed.
Feel free to pause the video here whilst you get what you need to start your journey.
Okay, are you ready?
Let's go!
I'm Elisabeth, I'm studying observations of debris disks and trying to find debris disks and giant planets.
So, the planets will form over maybe four or five million years as the star forms.
So the star forms out of a massive cloud of dust and gas
and that collapses down and the center of that will fall inwards and become a star.
But then there'll be a whole cloud of dust and gas and stuff left and that
kind of collapses down into a disk that's just made out of kind of the leftovers from the star formation.
And that disk, the individual bits of dust, will collide to each other and they can sometimes stick together.
We don't really understand that yet. Sometimes they stick and sometimes they bounce off. and no one
And no-one really knows how they can stick together enough to start to form a planet.
But then as soon as you have a big core, we call it a 'planetesimal'.
So it's maybe ten kilometers across, that's big enough that it's gravity starts to scoop up all
of the rest of the nearby stuff and then it kind of slowly picks up more and more
bits of dust and gas and they fall down onto the surface and eventually it grows
into something like Jupiter or even bigger than Jupiter.
I'm Professor David Sing, and I study transiting exoplanets and their atmospheres.
Well, Hot Jupiters are gas giant exoplanets, but they orbit much
much closer to its star than Jupiter does to our own Sun. and crack the orbits
In fact, they orbit so close that the dayside of the planets are heated up to thousands of degrees Kelvin.
And because they're so hot a lot of the atmosphere around the planet actually evapourates off.
Sort of like when a comet gets too close to the Sun,
you see a lot of evaporation of the comet happen, a similar process happens for these planets;
they orbit so close, a lot of the atmosphere is being blown off
Because these planets are so close, we expect them to be tidally-locked,
which means the same part of the planet will always face the Sun.
And what that does is set up a very large day/night contrast in temperature
It's very hot on the day side, and it'll be quite a bit colder on the night side.
And this will in turn create large-scale weather patterns around the planet.
This planet is so close that the tidal gravity is starting to distort the planet itself.
If this particular planet was any closer, it could actually break apart but what
But what might it look like inside the atmosphere of one of these extreme gas giant exoplanets?
Let's find out.
My name is Steph Lines, I'm an exo-nephologist,
which is someone who studies clouds on extrasolar planets.
So what we're looking at is planet Osiris, otherwise known as HD209458b,
and these are extremely strong winds, going from the west to the east of the planet,
from the date of the night side, the wind speeds are reaching about five kilometers per second;
which is about ten times faster than concorde.
Osiris has a temperature of around a thousand degrees centigrade, with these temperature ranges
we're not really looking at water clouds like we have here on Earth. But at these
much higher temperatures, we have the sort of evaporation and condensation cycle
of things like iron and silicates. So these planets might actually have
molten iron rain, and silicate or glass rain. Which is incredible, because with
these wind speeds of five kilometers per second, you're effectively going to be
lacerated by this glass rain and molten iron.
So these aren't particularly great places to visit
My name is Nathan Mayne, and I study the atmospheres of planets we've discovered around distant stars
Our next destination is the surface of a water world.
This is a 'Super Earth', as it's called. In our own solar system we have
no planets which exist in the size range between Earth and Neptune.
But actually, as we observe off into the galaxy, we find this is one of the most common form of planets.
We think that many of these have kind-of rocky cores. They're terrestrial planets essentially,
but they're likely to have a huge ocean.
Now they're Super Earths, they're much larger than Earth, they might have much stronger gravity.
And they probably have much thicker atmospheres. That means, any land features that are on these planets,
any rocky features, are going to be weathered and suppressed and effectively destroyed.
As you can see, the surface is being distorted by huge waves.
There's many reasons that could cause these waves: you have an ocean which is not interrupted by land masses,
So many of these planets we expect could have moons or multiple moons even, which create the same tidal
effects that their own moon causes in our oceans on Earth.
Additionally, actually, many of these objects might be undergoing significant tectonic activity
beneath the surface of the ocean, and these waves have no landmass to crash into.
So they really can build to quite substantial sizes
Our next destination is the surface of 55 Cancri e.
This planet orbits so close to its central star it's incredibly hot.
We think temperatures of a few thousand Kelvin, or few thousand degrees.
We know from how much this planet wobbles it's star, due to the gravitational interaction,
that this planet is about eight times the mass of the Earth. And we also know from it's sort of transit,
when it eclipses the central star, that it's probably about twice the diameter of Earth.
So this planet is incredibly hot and has a very strong gravitational field.
So what you can see is a molten lava field underneath you, where the surface has been disrupted and melted.
And much of that material potentially be lofted into the atmosphere and what you end up with
is a very soot-laden atmosphere, full of particulate matter, molten rock,
and condensing rock and raining sort-of silicate particles. And you're going to have huge
amounts of charged material flowing in the atmosphere,
and that will lead us to have significant thunder storms.
So, effectively, this is a pretty nasty place. Probably as close to Dante's Inferno as you can imagine;
with a molten lava surface, raining block, and constant planet-wide lightning-storms.
My name is Jessica Spake and I'm interested in studying exoplanet atmospheres.
TRAPPIST 1e is a fascinating system.
It was a wonderful surprise to find seven fairly Earth-sized planets so closely
spaced together around this tiny star. The star is actually about the size of Jupiter.
It's really like a solar system in miniature.
So here you can see the star's a lot cooler redder and smaller. You can see it looks very big in the sky here
That's not because the star is bigger, that's because the planet is a lot closer to that star than we are to the Sun,
So, these planets can be very close in and still be kind of about the same temperature as Earth.
We have discovered over 3,000 exoplanets,
but we've only searched less than one millionth of a percent of our galaxy.
There are billions more worlds out there for us to find in the Milky Way,
and billions more galaxies beyond our own.
Each new planet we discover changes how we view the universe and our place within it.
But, so far, we've only found one planet Earth.
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Thanks for watching.