You may already have read about the recently discovered comet that could become a naked-eye object in September. For those in the northern hemisphere, this is the week it could happen.
Hideo Nishimura, a Japanese amateur astronomer, discovered what is now known as comet C/2023 P1 (Nishimura) on 12 August. Computation of its orbit showed it would make its closest approach to Earth on 12 September at a distance of 78m miles (125m km), just five days ahead of its closest approach to the sun.
Comets are typically mountain-sized chunks of rock and ice. As they near the sun, the light and heat vaporises the ices, creating a cloud, known as a coma, around the nucleus and a tail that stretches through space. This causes them to brighten, and it is likely that comet Nishimura will be visible to the naked eye this week. The chart shows the view looking east from London at 05.00BST on 10 September. The comet is in Leo, the lion, and skirting the horizon, relatively close to the bright planet of Venus. On this particular day, a beautiful waning crescent moon will also be visible near Pollux, in Gemini, the twins.
