It’s easy to forget just how incredible it this that we live in age when anyone with a phone can instantly see photographs from space of anywhere on the planet. But if you go to Google Maps and zoom in, you’re only seeing the daytime view. 

There’s a whole other side to the planet, and in fact there are cameras in space specifically designed to capture the dark side of the Earth. Here’s a photograph from one, the Visible Infrared Imaging Radiometer Suite, or VIIRS for short.

What’s the point of photographing the Earth at night? Well, artificial light is the single most obvious sign of human habitation, so it’s a very effective way to track things like how cities are growing, how much energy a town uses, or where human activity is encroaching on protected environments.

So what does this particular one tell us? Well…

1) London may be pretty big but there’s still a lot of space inside the M25

OK, NASA didn’t spend millions of dollars on satellites just to tell us that London is in fact big, but seeing it lit up like this really reveals just how far it stretches. If you dropped it in the north-west, it would stretch all the way from Liverpool to Manchester.

The M25 shows up surprisingly clearly, too, as a ring of light a few miles outside the glow of the capital. So much for the Great Wall of China being the only structure visible from space.

2) The North West has almost merged into one big city

Between the Wirral – the spit of land opposite Liverpool – and Rochdale on the eastern edge of Greater Manchester, the land is almost totally aglow. Major towns like Wigan and Warrington sit between the two biggest cities, and others like Preston and Chester sit just outside their edges. 

Overall, the chunk of urbanisation in what used to be Lancashire and Cheshire has a population of at least 5 million, maybe 6 million depending how far you stretch those borders. That’s pretty big, and it rivals some of Europe’s other great industrial urban zones such as the Ruhr in Germany or Greater Milan in Italy. But it’s only around half the population of London despite covering a similar area. The North West is just too fragmented to be considered a single urban area.

3) The West Midlands arguably already has

The West Midlands is a bit more compact – from space, Birmingham, Wolverhampton, Walsall, West Bromwich and the rest have merged into a single glowing blob and only Coventry stands alone. But with a population around 3 million, it doesn’t have all that many people for an urban area of that size – there’s a lot of suburban sprawl – and besides, telling someone from Wolverhampton that they’re basically a Brummie is a recipe for an argument.

4) Almost no-one lives between York and Edinburgh (with one big exception)

When politicians talk about the North, they usually mostly mean cities like Liverpool, Manchester, Sheffield, Leeds which aren’t really all that far north. In fact, York is only halfway between London and Edinburgh by train. There are huge counties between the two like North Yorkshire, Cumbria, Northumberland, Scottish Borders and Dumfries & Galloway, but all these have relatively small populations and no real cities.

Except… there is one giant blob of light in the North East stretching from Newcastle to Middlesbrough. This is the Durham coast, where convenient river ports and reserves of coal created the giant conurbations of Tyneside, Wearside and Teesside. Together with the city of Durham, these have also kind of blended into one big coastal city with a population of 2 million or so.

5) Nearly everyone in Scotland lives in the middle

Scotland has a population of around 5.4 million. Around 3.5 million of them live in the “Central Belt” around Glasgow and Edinburgh. That means that about two thirds of Scots live in that bright stripe across the middle of the country. Geographically, it’s not a major surprise – the Central Belt is built around relatively low-lying river valleys in an otherwise very mountainous part of the world, so it’s one of the few places in Scotland where you could build a major city. But it’s not the only one.

6) No wonder Aberdeen’s so rich

So, what’s the deal with all the lights in the top right corner, where’s there’s no land there at all, just open sea? Well, those lights are the flares from oil and gas rigs. 

The vast majority of these are in Scottish waters, and the nearest major port is Aberdeen, located on the jutting out bit of north east Scotland. This has made the city the perfect place for oil companies and all the engineering, transport and processing industries that come with it. I don’t know if you’ve heard, but oil is quite valuable, and oil companies have a lot of money.

7) The Welsh valleys are pretty unique

Being so rough and mountainous, Wales doesn’t lend itself to urban sprawl. Most of the population lives in South Wales, with around 30 per cent of the population in the valleys around Cardiff. These used to be strongholds of the coal and steel industries, and the influx of workers into these steep walled valleys produced long “linear towns” stretching out like fingers from Cardiff and Newport. The industries have mostly gone, but towns like Caerphilly and Methyr Tydfil remain, and as the map shows, there’s really nowhere else in Britain quite like them.

8) Ireland’s cities just aren’t that big

Dublin shows up well enough on the night time photo, but the other cities on the island of Ireland are surprisingly hard to spot. Belfast and Cork are pretty clear if you know where they are, but other major cities like Limerick and Derry barely stand out from the villages around them. 

The reason is simply that these cities are relatively small – Derry may be the fifth largest city on the island, but its urban area still only has 90,000 people.

A lot has been written about the history of Ireland’s population changes – so much that there’s a Wikipedia article literally titled “Irish population analysis”. Just before the Great Famine, the island had a population of 6.5 million, but when the food ran out many people emigrated, and while Great Britain was growing, Ireland was shrinking. When industry came, it was focused mostly on the major ports, particularly Belfast and Dublin, and the services like banking that followed ended up being even more Dublin-centric. Ireland’s population as a whole has finally returned to pre-Famine levels, but that population is concentrated almost entirely in one or two cities.

9) Its towns are surprisingly regularly spaced

Let’s look at Limerick again. Between it and Dublin is a string of tiny towns. These include (going east to west) Nenagh, Roscrea, Portlaoise and Newbridge. According to Google Maps, Limerick to Nenagh is about 8 hours walk, Nenagh to Roscrea is 6 and a half, Roscrea to Portlaoise is another 8 hours, Portlaoise to Newbridge is about 8 and half, and Newbridge to the centre of Dublin is another 8 and a half. 

In other words, each town is day’s walk from the next. Long ago, these towns will have grown up around inns and markets, and this created a very regular grid of towns across the landscape. 

On a bigger scale, you can see the same thing in Great Britain. Heading south from Sheffield there’s a long string of major towns down the M1 motorway all the way down to London – Chesterfield, Nottingham, Leicester, Northampton, Milton Keynes and Luton – roughly evenly spaced. It’s almost like a grid stretching across the country.

10) South East England doesn’t look like North East France

Only about 20 miles of open water divide Dover and Calais, and in fact for much of its history, Calais was English territory. 

But geographically the two look very different. Kent is on the outer edge of London’s commuter belt, and it has a several reasonably large towns like Ashford, Canterbury and Maidstone. Across the water, the land around Calais is almost empty – in fact, much of it is a protected nature reserve. In the very corner you can see the French city of Lille and its surburbs, which spill over the Belgian border to the city of Kortrijk. And beyond that? Well, that’s something for another post.