A night on the coast
Will Gater explores what the UK’s many miles of coastline have to offer astronomers and astrophotographers looking for new perspectives
How a sea view can give you a fresh outlook on the stars
We’re certainly not short of coastline here in the UK. From the wave-smashed cliffs facing the might of the Atlantic at Land’s End in Cornwall to the shining, sandy beaches scattered around Scotland’s stunning shores, there are thousands of kilometres to explore. Yet while these enchanting saltspray flecked landscapes offer sea vistas by day, they’ve also got much to offer astronomers and astrophotographers after the Sun has set.
Many coastal locations around the country have public spaces where it’s possible to set up equipment for observing – once current restrictions surrounding the pandemic permit, of course. Though, naturally, you can’t just plonk your scope down anywhere, if you do find a suitable spot you’ll soon see why these sites can be great places to view the stars.
The advantage that is often immediately most obvious – especially to those of us living in towns and cities, where we have to contend with buildings crowded around us – are the great sightlines and wide, open prospects that coastal locations afford. With broad, sweeping views overhead and right
down to the sea you’re often able to see so much more sky than in a built-up urban location.
A coastal viewing site can be great for meteorwatching – especially during the stronger annual showers, like the Perseids in summer and the wintertime Geminids – as you’ve got a better chance of seeing meteors if you can see more sky. It can also be useful if you’re a beginner trying to learn your way around the constellations, as it can be easier to relate different star patterns to one another when you can see more of them in a wider context. To add to this, anyone who’s ever watched a moonrise over an eastward sea horizon will tell you just what a magical naked-eye sight that can be. Full Moon rises (see box, page 32) are particularly special, with the deeporange lunar disc slowly appearing over the water and its ‘glitter path’ dancing as it climbs higher in the sky.
Revealing low objects
That brings us to another thing coastal viewing sites offer observers looking for a challenge: a view towards a flat sea horizon doesn’t just provide a more open outlook, it also gives you pretty much your best chance of catching celestial objects that sit low in the UK sky – such as certain deep-sky targets and transitory sights like low-altitude comets. If you’ve got rooftops or trees and bushes around an inland site where you normally observe, chances are you’ve got a swathe of objects that you either can’t view at all or struggle to see through the obstructions.
One of the richest regions of the sky that’s often hard for UK-based observers to get a good look at – due to its inherently low altitude from UK latitudes – is the patch that sits towards the very centre of the Milky Way in the Northern Hemisphere summer months. This area, around the famous pattern of stars known as the ‘Teapot’ in the constellation of Sagittarius, the Archer, contains several truly superb observing targets for balmy summer nights; these include the beautiful Lagoon Nebula, M8 (see box, page 32) which is a great target for binoculars and a small telescope; as well as the globular cluster M22, which sits against the star fields of the summer Milky Way. As an example of how elusive these two objects can be with an obscured – in this case, southerly – horizon, around the time that darkness returns in early August in Scotland (at roughly 56°N latitude) both M8 and M22 sit well below 10° altitude; 10° on the sky, remember, is approximately equal to half the diameter of an outstretched hand at arm’s length – not a great distance by any means. The situation for these celestial objects is only marginally better from the most southerly parts of the UK, which is why anything you can do to find a lower southern horizon – such as observing from a south-facing coast – will improve your chances of getting a clear view.
No land in sight
Those clear views can also be aided by the fact that when you’re looking directly out to sea from the UK, there are generally no land masses for many tens, if not hundreds, of kilometres. This can mean there
are far fewer light domes from towns and other settlements (near or far) on the horizon around you, making visual observing that much easier. What light pollution there is in a sea view is usually limited to the lights from distant ships or fishing vessels. Imagers may be able to pick up the light domes from very distant regions in long exposure nightscapestyle images – for example, from the south Devon coast it’s possible to detect the glow on the horizon from the Channel Islands and parts of northern France – but by and large you’ll likely notice an improvement in light pollution levels compared to most inland UK sites.
Imaging possibilities
Speaking of imagers, all the benefits to visual observers mentioned above also apply to anyone trying to do astrophotography. For example, a coastal horizon, free of obstructions, enables you to shoot low-altitude displays of noctilucent clouds (see box, above). You’ll also stand a better chance of capturing the glow of the Zodiacal Light over an inky-black expanse of sea than you might when looking out over inhabited regions in inland locations; in those spots, light pollution along the horizon can often swamp the lower-altitude part of this faint phenomenon. And all this is to say nothing of the innumerable aesthetic and compositional opportunities coastal astrophotography can bring.
Reflections – from bright planets, stars and the Moon – on rocks and wet sand can add a magical glittering quality to images. If you experiment with long exposures to blur the water and the motion of waves you can create luminescent textures in a scene that can grab the eye and pull the viewer into the composition.
Nocturnal effects: use long exposures to blur waves, and reflections to create eye-catching imagery like this view of Dorset’s Mupe Bay
Staying safe
Undoubtedly, though, the most important consideration when it comes to seaside stargazing must always be safety. The coast can be a dangerous location even in daylight, and at night there are numerous hazards that one needs to be mindful of too – slippery or uneven terrain, water and changing tides to name a few. Stay away from cliffs and other areas of dangerous ground and always consult the tide times, as well as any local safety information and signage. The usual advice for those venturing out to view or shoot the stars also applies – that is, tell someone exactly where it is you’re going and when you expect to return, and dress for the conditions making sure to carry a fully charged phone and torch with you. A daytime recce of your intended viewing/ photography spot can help you anticipate any issues – especially if it’s an area you’re not very familiar with.
The effects of inclement weather are often also keenly felt at exposed seaside spots, so you will – naturally – want to keep an eye on forecasts and the latest satellite imagery ahead of any trip. That’s true not just from a safety point of view, but also because coastal spots can suffer from sea fog and haze, which can adversely affect observations. The Shipping Forecast, from the UK’s Met Office, includes a general note about maritime visibility and there are also satellite images available online which can give hints of where fog may be forming. You’ll also want to be wary of onshore breezes that can lift sea spray up into the air, as you don’t want that getting anywhere near sensitive, or expensive, camera and telescope optics.
Whether you’re an imager or an observer or a mixture of both, with the possibility that in the coming year we’ll return to something resembling normal life, a trip to the coast might be just the thing that many of us need to reinvigorate our bond with the stars. Indeed, with plenty to be found shining above distant horizons to remind us why we took an interest in the night sky, the coast’s greatest draw could well be the inspiration that flows from it as the waves lap and break in the salt-scented cool of the evening air.