The sun looks in this picture as if someone had pulled a zipper over it or drove across it with squeaky tires. The dashed line, which apparently divides our star, is actually the international space station ISS, which is just passing the sun disk. The picture consists of several temporary shots that were later put together to make a composition in order to make the entire course of this transit visible.
Of course, the ISS does not really move around the sun or even near it. It circles the earth at a height of about 400 kilometers, while our star is around 150 million kilometers away. But from the right point of view, the quick flight of the orbital space station as a tiny shadow tear in front of the glowing sun disk can be visible – a rare moment that only takes a few seconds.
The Chinese photographer Zhang Yanguang captured this special scene at the end of January 2025 – from the port city of Xiamen on the southeast coast of China. The spectacular sunscape is now one of the 30 finalists of the international competition “Zwo Astronomy Photographer of the Year”. Yanguang’s competition consisted of more than 5,500 photographers from 69 countries who also applied with their works.
The competition is organized by the Royal Observatory Greenwich and sponsored by the Chinese astrophotography company Zwo. The winners will be announced on September 11, 2025 and rewarded with prize money of up to 11,600 euros for their submissions.
