Looking ahead, Xu hopes to be able to capture photos of even better quality. To do so, he noted, would require him to shoot in an environment where there is less light pollution.

"Within the next five years, I plan to have a remote platform installed in a place with less light pollution. Unfortunately, there will have to be a trade-off-I won't be able to be as closely involved in the process because of its remoteness," he says.

According to Xu, many astronomy enthusiasts set up their telescopes and cameras at facilities in Yunnan province and Xinjiang Uygur autonomous region, where there is minimal light pollution.

These equipment will then be connected to the internet and looked after by caretakers, allowing them to take photos remotely via their computers. The annual fee of renting a space at this facility is around 20,000 yuan, Xu adds.