At this time of year, every evening, House Martins gather in the sky above our house. For over 25 years they have provided the soundtrack of our Summers. As the sun sets, and as they pitch and turn, they occasionally catch its light so that their white markings flare like ephemeral satellites against the darkening sky.
These are the tracks that they make above our house. We also have a young House Martin family that live in a muddy home attached to ours.

14.99 second exposure.

23.17 second exposure.