Photo/IllutrationThe Milky Way in the night sky above Nayoro, Hokkaido, and the Nayoro Observatory (Provided by the Nayoro Observatory)

NAYORO, Hokkaido--Officials here have been beckoning stargazers to come and enjoy some of the most pristine dark skies in Japan at night.

Now, they have the full endorsement of the Environment Ministry.

The night skies above Nayoro are dark enough for sky-watchers to examine the complex glowing band of the Milky Way in detail, according to a ministry survey.

“We have been insisting that stars can be seen clearly from Nayoro, and the ministry findings corroborate our argument,” said Nayoro Mayor Takeshi Kato. “I want to take advantage of the dark skies and bright stars as tourism resources.”

The municipal Nayoro Observatory sent an image taken this past summer of the night sky to the ministry, which started surveying the darkness levels of skies across Japan in fiscal 2018 based on photos taken by local officials and residents with digital cameras.

The ministry research is carried out biannually in summer and winter to raise awareness of light pollution and environmental preservation through stargazing.

According to the survey results released by the ministry late last year, the night sky image snapped by the Nayoro Observatory on Aug. 4 showed a sky darkness level of 21.1.

Higher darkness levels mean the sky in the background is darker and stars can be seen more clearly. In skies with a darkness level of 21 or higher, it is said that “the complex structure of the Milky Way can be examined and star clusters observed.”

During last summer, night sky images were also sent from Hakodate and Matsumae, both in Hokkaido, to the ministry. The darkness levels were 18.0 and 19.2 for photos from Hakodate, while Matsumae recorded a darkness level of 20.8.

Although the darkness level of an image taken above Teshikaga, Hokkaido, was estimated at 21.9, the photo was not shot during the research seasons.

The Environment Ministry is considering continuing to collect data and setting sky darkness standards to evaluate how easily stars can be observed.