We did another early morning walk today.  The alarm went off at 4.30 am.  I know it sounds mad, but once you get over the trauma of getting up at that time, it is really quite exhilarating. We were up at the same time as my previous post as we are now in British Summer Time, when everything is an hour earlier. So we were up and out during ‘Nautical twilight’. Twilight itself is when the sun is still below the horizon, but there is still light shining into the sky. You can see it at both ends of the day before dawn or after sunset. It is divided into three different zones, Astronomical twilight is when the sun is between 12 and 18 degrees below the horizon. As a general guide, it’s when you can just see the last hints of the sun after sunset – or in the morning as you see the first suggestion of light.  Nautical twilight is when the sun is between 12 and 6 degrees below the horizon and sailors (or anyone else) can still see stars to navigate by. This is definitely the precursor to the dawn and it’s easy to tell that the sun is on its way. Finally there is civil twilight when it’s really quite light as the sun approaches the horizon. 

A useful diagram from Wikipedia, for anyone needing clarification. 

For anyone else, here is this morning’s nautical twilight looking over North Leeds in Yorkshire. It was certainly worth it, though astonishingly cold for this time of year. We were wrapped up as if it was January. We did a different walk to our usual one, along a ridge of native woodland that has escaped the developers as it’s so steep. It really was great with a full orchestra of birds and some yelping foxes to accompany us.