Joseph Mallord William Turner, 'The Evening Star', about 1830

In contrast to many of Turner’s paintings – often full of activity, grand architectural settings, dramatic weather and dazzling displays of colour and light – this is reduced to its most fundamental elements: day and night, land and sea, earth and sky.

Yet the picture has a subtle construction. Three near-symmetrical vertical markers – the posts in the sea, the bright reflection of the star on the water and the young boy who wades in from the shoreline to be greeted by a small leaping dog – give structure to the space around them. They also create a diagonal rising from right to left that leads our eye to the distant horizon, where an inky black sea meets white clouds.

The title of this painting was not chosen by Turner, but appears to have been given to it around 1906 while an inventory of the Turner Bequest (the gift of his paintings he left to the nation in his will) was being compiled. Some 11 lines of verse scribbled by Turner in a sketchbook he was using around 1829–30 (probably when this painting was made), include the phrases: ‘Where is the star which shone at … Eve / The gleaming star of Ever … [or Eve] / The first pale Star of Eve ere Twylight comes …’. The words reveal Turner’s attempt to find a poetic language to describe the sequence of the ‘pale’ evening star being overpowered by the more ‘powerful ray’ of the moon.

Even if these lines do not relate directly to this painting, they show that he was keenly interested in transitional moments, such as twilight or dawn, when one period of the day or night is superseded by the next. The star itself is a tiny dab of thick white paint. The ghostly trace of a boat to the right of centre, which has been painted over, suggests that Turner decided to emphasise the vastness of the sky and sea rather than human industry.

Although the painting was originally thought by critics to be unfinished, it is possible that Turner was in fact satisfied with its evocation of a particular moment and did not see any need for additional work on it.