HAVING provided the scores for films from Gladiator to The Dark Knight and Dunkirk, Hans Zimmer knows a thing or 30 about generating excitement on screen.

“Every director I’ve ever worked with only wished they could have had a car chase or action scene like that,” the composer tells Planet Earth: a Celebration (BBC1, Monday, 8pm, above). He is referring, of course, to the famous baby iguana chase in Planet Earth II, as shown again in this compilation.

To set the scene: marine iguana hatchlings are poking their heads out of the sand for the first time. Their mission is to get to the sea. It should be a short, simple scramble across the beach and rocks, but lying in wait for the newbies are racer snakes, superfast slitherers who regard baby iguanas the way some of us do white chocolate Magnums.

We watch young ‘un after young ‘un make the dash. It’s always the same. The little one edges out cautiously, sees nothing, and starts walking. Then the snakes appear from the rocks and all the viewer can do is shout “RUN!” It’s carnage. Then we come to the contestant I like to call “Lucky”. Even though you may have seen his dash countless times it is impossible not to cheer the little fella on. (It could have been a little lady; it was moving too quickly to tell.)

The iguana chase is one of eight classic scenes from Planet Earth II and Blue Planet II. The reason for the compilation, other than filling a gap in the schedules? “To lift the nation’s spirits during a time of crisis,” says Sir David Attenborough in a new narration. There is a new score, too, courtesy of Zimmer and the rap artist and classically trained pianist Dave.

It’s all here, the bottlenose dolphins surfing “for the sheer joy of it”; the shark v octopus fight; a pack of lions trying to take down a giraffe; flamingoes parading; the whales and their hunting calls. As Attenborough says, “In times of crisis the natural world can be a source of both inspiration and escape.” Perhaps because of this determination to cheer us up there has been a scaling back on scenes of violence and death (though several remain).

Spectacular, thrilling and magical – the kind of film that makes you wish you had given in to demands for a telly with a screen the size of a pool table. Dang that innate good taste.

You have to hand it to Channel 4 when it comes to programme titles. Take new show Lodgers for Codgers (Channel 4, Friday, 8pm), which brings together young people who cannot get on the property ladder with elderly homeowners rattling around in big houses. Lodgers for codgers, see? A tad cheeky, but does the job.

Serious points are made by way of introduction. Did you know that four million over-65s live alone, while five million young adults will never be able to afford their own home? Or that three million young adults still live with their parents – 50% more than 20 years ago?

The scene set, the producers settle down to generating some reality show froth. A “speed dating” session is organised where young and old can meet to see if they would like to try living together for a week.

Marvell, 21, a poet from London, hits it off with retired teachers John and Lynne from Glastonbury. Living with his mother and sister in a cramped flat, Marvell craves some space and peace.

The episode’s second pairing is between Sophie, 20, a fashion student from Solihull, and Eunice, an octogenarian living in Birmingham.

You can tell immediately where the strains are going to show, and there is an element of trying too hard in some of the scenes. But that doesn’t mean it cannot be entertaining and a little bit enlightening at the same time – exactly what this kind of series should be.

The cynical (guilty as charged) will want to stay for the end credits to find out how it all worked out.

No sooner have you caught your breath after the first series of Harlots (BBC2, Wednesday, 9pm, 9.45pm) than the second one is beginning. The first couple of episodes, stuffed with bare buttocks, cackling women and off-colour jokes, were but a mere shop window display to tempt the viewer in. After that, Harlots became savage and bleak, the characters developed in surprising ways, and the stories took root.

The depiction of a rotten and corrupt London where women were there for the using and abusing makes for some shocking scenes. But the camaraderie among the gals – those that don’t hate each other, like rival madams Margaret Wells and Lydia Quigley (Samantha Morton and Lesley Manville) – is heartening.

Finally, hands hovering over imaginary buzzers please as Darwin College Cambridge take on the University of St Andrews in University Challenge (BBC2, Monday, 8.30pm). No Googling at the back, now.