Brian Cox’s voice is so calming, and the beauty of the planets depicted in his latest show so stunning, that the violence of the story he has to tell rather jars.

In his ambitious new five-part series The Planets, Brian looks at 4.5 billion years of cosmic history to try to work out how each of the eight planets in our solar system ended up as they are.

It’s a story of collision and competing interests – and it raises the possibility of the end of the world as we know it.

‘The threat of an asteroid strike is very real,’ says Brian, 51, a professor of particle physics and former pop star whose genial manner and jolly grin belie the message he has to tell.

In his ambitious new five-part series The Planets, Brian Cox (pictured) looks at 4.5 billion years of cosmic history to try to work out how each of the eight planets in our solar system ended up as they are

‘There have already been several big ones that have changed the way the solar system works. There’s a saying that if the dinosaurs had had a space programme, they’d still be around.

'We live in a challenging environment but the more technology we develop, the more we are likely to survive. This isn’t science fiction; it’s a real issue.’

Brian explores how new technology is allowing us to learn more about the planets within our solar system and beyond, and consequently more about the Earth.

He believes that eventually humans will live on Mars and says it is not only important but necessary for our species to colonise other planets.

‘There may already be Martians; that’s something we’ll find out when we get there,’ he says.

‘But if we are to have a future, at some point we will need to become Martians. That’s clear to me, because we can’t stay here forever.

‘It’s not just because of the threats to our planet. There’s a strong idea that the great challenge on Earth is to manage an expanding population and a civilisation that requires new frontiers both intellectually and physically but is confined to a very small planet with a lot of pressure on the resources.

'The solar system contains essentially infinite resources. I talked to the Amazon boss, Jeff Bezos, who has a company that makes rockets and wants to start space colonies, which sounds like science fiction until he points out that all the resources and energy and things you need for heavy industry are out there in space.’

It’s pretty mind-blowing stuff, even though Brian admits he has no intention of being one of those pioneers.

‘It would be horrendous,’ he says. ‘Freezing cold, very little atmosphere – it really is the frontier, but there’s a certain kind of human that wants to be on the frontier.

Professor Brian Cox on location in Lanzarote while filming The Planets. This dark, finely ground volcanic soil is similar to the powdery regolith of Mercury

'Throughout history, frontiers have been problematic in terms of access to resources.

'So they drive you to develop new technologies and find new ways of existing. If we had a colony on Mars, suddenly we’d be faced with profound challenges.’

But it’s not just our future that Brian looks at on the show. The BBC series starts by examining the four rocky planets closest to the Sun – Mercury, Venus, Earth and Mars – using the most cutting-edge cameras out in space.

Today, Mercury is a barren world, Venus is scorching hot and Mars is freezing cold, but Brian reveals that each of these planets had a brief moment in time when they enjoyed almost Earth-like conditions.

We see the greenhouse effect in action. It isn’t just interesting; it teaches us that while we are very fortunate indeed, we are also in a rather precarious position.

New theories explored in the series suggest that not only did our solar system not emerge in the way we thought, but also that things are far more volatile up in space than we imagine.

‘What’s been remarkable over the past decade or so is how much detail we’ve been able to learn about our solar system, thanks to new probes into space, and how much we’ve learned about other solar systems too,’ Brian says.

‘We can now see well over 3,000 planets around distant stars, and what we’ve realised is that other solar systems don’t look like ours.

‘The theory is that ours is the remnant of a giant cloud of dust and gas that collapsed under gravity, but we’ve learned really quite recently that this is not the case.

'The solar system was very dynamic, planets were moving around all over the place in the early years, and things are still changing.’

One theory he looks at is called the Grand Tack Model, named after the way a sailing boat ‘tacks’ into the wind to change direction.

It suggests that the giant planet Jupiter was heading towards the Sun when it came close to colliding with Saturn, sending them both spinning violently in different directions, with Jupiter turning back to the outskirts of the solar system.

The theory is also used to explain why Mars seems relatively small for a planet, having a volume less than a sixth of Earth’s, because when Jupiter was expelled to the outer reaches it took with it a large number of planetesimals – the small celestial bodies that were pulled together by gravity to form the planets – from the Mars region, leaving it largely empty so that Mars couldn’t grow.

‘What’s interesting about our solar system is that it’s still unstable,’ says Brian.

Professor Brian Cox on location near Rjoandefossen in Norway while filming The Planets

‘We tend to think of planetary orbits as being like clockwork that will go on forever, but they may not.

'It’s fundamentally a chaotic system, and if something happens – like another planet coming into the system – then everything gets thrown around. It’s settled now because the instabilities have been thrown out.’

The show looks at the quirks of each of the planets and the Sun itself – from Venus being like a greenhouse to the theory that, as the Sun ages, it will massively expand and get much closer to the planets.

But for Brian the big purpose of the series is to teach us more about our own planet.

‘I do believe that valuing our world is so important,’ he says. ‘You tend to see that message coming from environmental programmes, which is understandable, but you can see it in cosmology and solar system physics as well.

‘If you look at a planet such as Venus, it’s about understanding what a change of atmosphere can do.

'This is a planet that was probably Earth-like several billion years ago, and is now often described as a vision of hell.

It’s the hottest place in the solar system other than the surface of the Sun, and that’s because of the way its atmosphere changed.

'We see the greenhouse effect in action. It isn’t just interesting; it teaches us that while we are very fortunate indeed, we are also in a rather precarious position.’

The Planets begins on Tuesday at 9pm on BBC2.