Come in… Hello? Is anyone there? Can you read me? 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.
