How to walk the Solar System

There is no atlas big enough to contain an accurate scale drawing of the solar system. The distances and sizes involved are just too mind-bogglingly complex. If Mars really was the astronomical equivalent of two inches to the right of the Earth, we’d have set up a branch of McDonalds on it by now. As Douglas Adams put it in The Hitch-Hiker’s Guide to the Galaxy: “Space is big. Really big. You just won’t believe how vastly, hugely, mind-bogglingly big it is.”

Happily, there is a walk you can do that will embrace the boggling and actually show you just how big space is. It’s in Somerset. On a canal.

The Somerset Space Walk was the bright idea of Tauntonian inventor, poet, astronomer and general dreamer of interesting things Pip Youngman. Fed up of the inability of books to portray the solar system accurately, he set about thinking how to do it in a real and exciting way. He found inspiration in the Bridgwater and Taunton Canal, which runs for 14 miles between his home town and neighbouring Bridgwater. As he worked it out, 14 miles was a perfect distance to create a scale model of the solar system. Two, in fact.

He reduced the solar system to a scale of 1:530,000,000, which means that 1mm on the ground equates to 530km. Then he stuck the model of the sun at the centre point of the canal, and installed two sets of nine planets, one set going north to Bridgwater, the other going south to Taunton. Both models are in the same scale, so in either direction you’ll walk from Sun to Pluto in 6.8 blissful, quiet miles of canalside ambling.

I say blissful and quiet; but actually there’s a lot of mind-blowing that goes on with this walk. It’s not just the distance from planet to planet; it’s the size of them too. The Sun is the size of a Smart car. Pluto is 6.8 miles away and the size of a pea.

That was Pip’s point: when you see the true scale of the solar system, your jaw should drop and your brain should go slightly wonky. His dream became reality in 1997, and ever since then, space explorers have come to Somerset for a healthy burst of mind-blowing. Sadly, Pip himself left the earth in 2007, but he has left behind a fantastic learning tool

– and the most unusual canal walk in Britain.

It all starts at the mid-point of the canal, which is Maunsel Lock. Pitch up at the tearoom-cum-visitor centre and you can’t miss it, in all its yellow-orange gaud: the Sun. Helios in Greek, Sol in Latin. The reason for our continued existence. A raging ball of superhot plasma, 865,000 miles wide, represented by an 8ft, 14-ton concrete sphere.

Winter is the best time to visit, because the bare trees around the model make it all the more stark and spectacular. Visit in summer, and it’ll be partly shrouded by a small tree – a problem the real Sun generally does not have.

And next to it, the canal: your companion for the next seven miles. We chose to head north to Bridgwater, but whichever direction you follow, you’ll find the canal makes friendly company.

The first thing you realise is that the solar system is a game of two halves. Mercury, Venus, Earth and Mars are the first half because they are, galactically speaking, near-neighbours of the Sun. So as you cross the bridge and descend to the towpath, the Mercury plinth comes into view straight away.

In fact, all four inner planets lie within 220ft of the Sun. After you leave Mars, you won’t reach the next one – Jupiter – for almost a mile.

Each marker gives information about the planet you’ve landed on, in Pip’s wonderful hybrid of scientific detail and whimsical musing. For instance, here’s Venus: “A strange place, the day longer than the year. Under a vast, dense atmosphere of carbon dioxide laced with clouds of sulphuric acid there lies a scorching desert. No air, no growth, no seas. Earth’s nearest neighbour and size-twin… and yet, so different.”

Each inner planet is a stainless steel ball mounted inside a hole in the plinth. Mercury is the size of a marble; Venus and Earth the size of largish conkers. Look back at the great orange orb of the Sun, and your mind is already coming to terms with the wrongness of all those books.

Earth is particularly fun, not least because there’s a fantastic geocache to be found nearby. No mere Tupperware box for this one; in keeping with the theme, it’s housed in a Peppa Pig space rocket.

But the best thing about Earth is the little notice at the bottom of the plinth which urges you to look for the Moon. Our own dear little satellite is represented by a tiny pin-prick in the concrete.

From Earth on to Mars, and still the Sun is distantly in view. But that all changes now, as you put your walking legs on and head along the canal and into the deeper reaches of the solar system.

There’s something very special about canal walking. Some may think it dull due to the samey features – footpath, water, bridges, locks. But if it were truly dull, would Britain’s canal walks be as popular as they are? The Kennet and Avon Trail, the Cheshire Ring Canal Walk, the Llangollen Canal and the Regent’s Canal in London: these are all adored by walkers for the new perspective they grant; for the serenity; for the history and heritage that comes with them – and for health too. The British Heart Foundation recommends canal walks as they are superb for helping you build and maintain a strong, steady walking pace, which in turn raises your pulse.

And if it’s history, heritage or wildlife you’re after, look to the Canal and River Trust, the publicly-owned body formed from what used to be British Waterways, which does a marvellous job of helping you access all those facets of canal life.

So what of the Bridgwater and Taunton Canal, then? Well, quite apart from the solar system model, it’s is a lovely canal to walk. All around is farmland, but to the east you get a sense of the Somerset Levels; a vast, flat wetland receding all the way to the foot of Glastonbury Tor, which of course makes the perfect accompaniment to the space walk if you’re here for a weekend – astronomy one day, spirituality the next.

Opened in 1827 at the height of the canal boom, the B&T links the rivers Tone and Parrett, creating an inland waterway that would allow goods to be transported easily between Taunton and Bristol.

It declined through the late 19th century, but during the Second World War it became part of the Taunton Stop Line – a defensive barrier designed to stop German invaders moving inland if they landed at Minehead or Weston. Plenty of evidence of the Stop Line survives along the canal: pill-boxes, gun emplacements, concrete blast walls. At one point during our darkest hours, every bridge over the canal was planted with explosives, primed to detonate simultaneously in a bid to halt the invaders on the western bank.

Thankfully, Hitler’s navy never came, and over time, the canal was reinvented for leisure use. Today the hoggle of narrowboat engines is the perfect peaceful soundtrack to your walk.

But of course, no other canal has a scale model of the solar system, and after two miles of steady strolling, you hit the big stuff. Far too big for the little holes that held the inner planets; the giants of Jupiter and Saturn are concrete half-spheres set into chunky pedestals. First Jupiter, the size

of a football: the largest planet in the solar system. Then a mile and a half on, opposite a gloriously swishy reed-bank, Saturn: slightly smaller, but marked out by its unmistakeable rings.

On again, and now as we head to the outer planets, the miles really stack up. The next stop is Uranus; if you’re in a group, expect the resident wag to come up with plenty of gags on the way to it. In our case, the most printable was: “Is this one Uranus or Urelbow? I can’t tell them apart.”

For these planets, we are back to the stainless steel spheres, although both Uranus and Neptune fill their alcoves entirely, underlining the fact that even these distant, cold worlds are far larger than our little home.

And finally, as you walk beneath the M5 and enter Bridgwater, comes Pluto. Six-point-eight miles from the Sun and the size of a small pea. And, in a slight act of anticlimax, located round the back of a Morrisons car park.

But never mind the setting: think of the feat that has brought you here; think of the scale. You left a yellow globe that could crush a car, and after three hours of solid walking, you’ve arrived at a tiny steel ball that is smaller than your smallest fingernail. That’s the solar system as it truly is.

But then there are some extra mid-blowing points to consider. One is that the star Rigel A (bottom right in the constellation of Orion) is so enormous that if it sat where our Sun sits, its outer edge would reach Pluto. It’s as big as our entire solar system – and it’s still only a medium-size star.

The second is that if Pip’s model were to show the next nearest star to our Sun – Proxima Centauri, part of whose very name means “near” – he would have had to create a 14-inch red ball and install it in a convenient location some 47,000 miles from Maunsel Lock. Except there wouldn’t be a convenient location, of course, because that distance is roughly twice the circumference of planet Earth.

Which brings us back to the biggest fact of all: space is big. Really big. This walk has been mind-boggling, and yet it has only taken you through one tiny corner of one little backwater of one smallish galaxy. A galaxy that is just one of billions, spinning in a measureless space that does not end, has no barriers or borders, and simply keeps going ad infinitum (as far as we know, anyway).

Mind boggled, blown and befuddled, but body fresh, cheeks ruddy and pulse pumping, it’s at this point that you’re rather grateful for the presence of the Morrisons at the end of the solar system. It has a café, you see, and after journeying into the farthest reaches of our interspatial neighbourhood, you’re always going to need a cup of tea. We’re sure Pip Youngman, genius and interstellar walker, would recommend that wholeheartedly.

WORDS: NICK HALLISSEY