Robyn Williams: But if we do get ads in the sky, will it be just a pain in the cosmos for astronomers, like Ed and Ali or Brian Cox? No, more than them. Try turtles, baby ones. Here's Dr Kellie Pendoley who is in Perth and helps run the Australasian Dark Sky Alliance. So, what's that?

Kellie Pendoley: So it's a group of people that are interested in protecting the dark sky that came together following a conference in Siding Springs in New South Wales a couple of years ago, Artificial Light at Night Conference, and we all realised at the end of that that there was enough interest in the country and across different disciplines that we needed to get together somehow and become the group that's the experts on protecting dark sky and advocating for dark skies in Australia.

Robyn Williams: Of course Siding Springs, where the mountain is, and where the Anglo-Australian telescope is, and it's wonderfully clear, isn't it, you can actually see the sky. But what problem were you trying to solve?

Kellie Pendoley: The problem we have is how do we reduce and stop light pollution. So there's all sorts of reasons why you want to do it, but basically it's to reduce sky glow from lights from any sort of human sources basically.

Robyn Williams: Is this all for astronomers?

Kellie Pendoley: No, it's not. I mean, astronomers actually drove this to begin with because of their need to be able to observe stars, and as light pollution started growing 20, 30 years ago, they are the ones that started to become more vocal about it, but nobody else cared back then because light is good, light is what we need at night and it's what makes us feel like rich Western societies, we illuminate the night and we can do things late into the night and it's an indication of wealth. But more and more we've learnt that this light at night impacts a whole range of different other receptors, humans and wildlife and heritage value of the night sky and things like that.

Robyn Williams: And turtles, how do they come into it?

Kellie Pendoley: Turtles are probably the poster child for light pollution because we've known how light impacts on turtles, and specifically hatchlings, since 1911, and some bloke called Hooker in the States did some studies with hatchlings and proved that the light was distracting the hatchlings when they were leaving their nest when trying to find the ocean. The cues they use to find the ocean is as they leave the nest they are looking for the lowest, lightest horizon, and they are moving away from the tallest, darkest horizon, and so that drives them seaward because it's always a little bit lighter over the ocean. Even with no Moon, the stars still illuminate the ocean just enough so it's just slightly brighter. And so when we put lights inland, all of a sudden they can't see that low light horizon anymore, so they crawl inland and get run over by cars and eaten by foxes and dogs or just dry up and die.

Robyn Williams: But even where they are, which is surely out of town, you have enough light to disturb them?

Kellie Pendoley: Yes, it's not point sources of light, so people think, oh, if I just shield a light, that's fine, but it's the glow that the light generates. And so when you add lots and lots of point sources of light together, they create a glow in the sky, and you can see it a long way away from Perth or some city and you look back and you can see a dome of light over the city, and that's what they are looking at and they are responding to that dome of light and that glow in the sky. They are integrating looking at the horizon, about 180 degrees around and 30 degrees high. And so whatever light is in that field of view, that's what they are going to crawl towards.

Robyn Williams: And you've watched them?

Kellie Pendoley: Yes, I have spent years doing it.

Robyn Williams: Where?

Kellie Pendoley: Lots of places. Barrow Island, we do a lot of work there, even now we still do all the turtle work for Chevron. And on other islands up in the Pilbara, Port Hedland, mainland coast, down around Onslow, I've also done this sort of work in Queensland and overseas.

Robyn Williams: So you go with your light meter and wave it around and say, no, this is too bright for the turtles, and you tell the big company and what do they do next?

Kellie Pendoley: More and more they go, geez, we need to do something about this. So 20, 30 years ago everyone would go, 'Kellie, you and your light!' Whereas now they are paying more attention, I think because everyone is realising that it's a shared value, you know, the turtles, the environment is important, there is this social responsibility. So more and more they will say to us, okay, well what do we need to do, how do we manage our lights? And so we look at the lights that are there, and now with old-fashioned lighting being converted over to LEDs it's a great opportunity to try and manage those lights a bit better. So I love LEDs because they are so easy to manage and control, you can turn them on and off instantly, which you couldn't do with the old lights, and you can change the colour of them and the intensity and you can have motion sensors on them. And if you use those and use them well, then they are a good solution, and they are also very directional. So whereas the old-fashioned lighting scattered everywhere all over the shop, 360 degrees, LEDs are very, very focused, so they are a good solution.

Robyn Williams: Yes, I remember a number of people saying why do you want to send a light up into the sky where it's useless, why don't you make sure it's pointing downwards where it is useful and where it's wanted instead of wasting a third of it.

Kellie Pendoley: Yes, exactly, and so that waste in the sky is what affects the turtles, that's what affects fledgling shearwaters, because when they take off for their first flight after they've fledged from the nest, they fly towards that and they crash into buildings and light poles and things like that. The other thing with that wastage, you look at the city at night and every light is on in the buildings and you think, why? And the energy that you need to generate to create that light consumes oil and gas and things like that, which produce greenhouse gases, so we are putting a huge amount of greenhouse gas into the atmosphere to keep lights on at night for nobody, for no reason.

Robyn Williams: I turned 26 lights off on the way into the office this morning.

Kellie Pendoley: There you go, exactly. So either you get solar panels to have free clean energy or you turn your lights out.

Robyn Williams: Do you get consulted by overseas people at all?

Kellie Pendoley: Yes, we've recently started to talk with some companies in the Middle East about helping with a lighting design for a big development on the Red Sea. We are not lighting designers. People are experts at that, professionals, but my group and I as biologists, we provide advice to those engineers and developers to make sure that they put the right lighting in and reduce their impacts.

Robyn Williams: Are you telling me that the sheiks like turtles as well?

Kellie Pendoley: Apparently they do, the King of Saudi does, and he's told his team that they will build this development, but they will also protect his turtles and the night sky. Amazing dichotomy. But anyway, we're going to do the best we can. They've also asked us to come over and help train them in how to do studies with hatchlings, we call them arena studies, where we release them on the beach and we measure where they go under controlled conditions. So if there is light around they'll crawl towards us, we can collect them and do stats on their little tracks and things like that. So yeah, we're going to do a bit of that this year I think.

Robyn Williams: Good luck.

Kellie Pendoley: It should be fun. I wasn't going to go, I figured they don't want a female, but they are quite keen for me to come, so I'm going to bring one of the boys from the office and we'll go check out the Red Sea.

Robyn Williams: Dr Kellie Pendoley in Perth. She is from the Australasian Dark Sky Alliance.