There’s a certain joy in venturing outside at night and navigating by the glow of the moon. Sadly the moon is never quite bright enough to read a street sign, or to illuminate a sidewalk hidden under a tree’s shadow—but a Chinese space company aims to fix that.
Chengdu Aerospace Science and Technology Microelectronics System Research Institute Company (CASC) plans to build an artificial moon that would be eight times brighter than the real moon, reports Chinese newspaper The People’s Daily. The fake moon would actually a satellite, built to light areas between 6 and 50 miles wide, and would replace streetlights in the city of Chengdu.
The satellite is expected to launch in 2020, and Wu Chunfeng, CASC chairman, says testing has already begun.
Meanwhile, other groups are trying to make the world dark again. A 2016 study showed that more than 80% of the world, and 99% of people in the US and Europe, live in “light-polluted” areas, where the sky’s natural glow has been altered by artificial light from buildings and street lamps. Entire cities, like Flagstaff, Arizona and Ketchum, Idaho, are actively working to reduce light emissions at night. Both are certified “dark sky communities” by a group called the International Dark Sky Association, which offers dark sky designations to towns, parks, reserves, sanctuaries, and other places actively working towards a “more natural night sky.”
Beyond aesthetics, there’s growing evidence that light pollution affects our health. Research shows excess light at night messes with our sleep, which is linked to increased risk for cancer, obesity (paywall), and depression. It also disturbs the natural patterns of wildlife: nocturnal animals like bats are less active in light-polluted areas; animals that use light to navigate, like birds and sea turtles, get confused (paywall); even plants’ lifestages are disrupted by the extra light. Cumulatively, these changes could alter entire ecosystems.
To address concerns about the artificial moon’s affect on wildlife, the People’s Daily quoted Kang Weimin, the director of optics at Harbin Institute of Technology, who said “the light of the satellite is similar to a dusk-like glow, so it should not affect animals’ routines.” But given that current levels of light pollution levels already throw off animal routines, a constant “dusk-like glow” would only make things worse.