How do small Japanese cities maintain dark skies? | Science

As modern lifestyles lead to uncontrolled artificial lighting, light pollution has invaded the skies above cities, obscuring the twinkling stars from the eyes of Earth's inhabitants. The evils of light pollution don’t stop there. At this point, its implications are not just for human life and safety, but for other organisms as well, including her biological clock and migration.

Thanks to the efforts of several international organizations, including the International Astronomical Union and the American Astronomical Union, Japanese residents have found a unique solution for themselves, turning their remote city into a beacon of extinguished hope amid the suffocating light. candle. .

The city of Misari on the southwest side of Okayama Prefecture, Japan, is home to many astronomical observation and observation centers, including the 40-inch Meichen Observatory that operates year-round, taking into account the urgent need to protect astronomical observations from any light pollution in the city's sky. Local residents still maintain a tradition of preventing them from damaging the city's sky.

In 1989, the city enacted strict light pollution laws, becoming the first local government in the country to pass such a law. City administration and observatories are working with Panasonic to provide for the creation of a dark, sky-friendly zone, and the city's public lighting is being replaced with LED lights with temperatures of 3,000 Kelvin or lower.

The specter of pollution

Although the city's residents maintain their traditions, they still face light pollution from other cities in the region, with neighboring towns still using very bright, high-temperature lights.

Japanese astronomers Ryosuke Itoh and Sayota Maino are collaborating to monitor the extent of the impact on vision at the Bercy Observatory between 2006 and 2023. The two scientists used a specially equipped device to measure the brightness of the sky to obtain a photometric value of the sky's brightness.

The results show that the brightness level of the city of Bessie is in the fourth group of the Bortle scale, a standard used to evaluate the level of light pollution in the sky. This means that the city is clearly located in a rural area. According to the scale, this clearly shows the effective use of light fixtures. degree of sex. ” LEDs have lower color temperature alternatives.