Artificial moons '8 times brighter than the real moon' to light up city streets

China wants to build three artificial moons “eight times brighter than the real moon” to light up city streets.
The moons will have an area anywhere between 10 to 80km wide.
It’s estimated the moons would save the city about 1.2 billion yuan ($240 million) in electricity costs every year.
It hopes to have the project completed in four years.

However some experts say it “potentially creates significant new environmental problems”.
Within four years, Chinese scientists plan to have three artificial moons “eight times brighter than the real moon” shining down on their city streets.
Can it be done? The project has already been developed by the Chengdu Aerospace Science and Technology Microelectronics System Research Institute Corporation.
China’s fake moons, according to state media People’s Daily, will light up the streets of Chengdua at night with “a dusk-like glow” across an area anywhere between 10 to 80km wide — bright enough to replace streetlights.

Wu Chunfeng, chairman of Chengdu Aerospace Science and Technology Microelectronics System Research Institute Corporation, said if the moons could light up 50km of Chengdu at night, it would save the city about 1.2 billion yuan ($240 million) in electricity costs every year.
The three moons would be made from reflective material and operate alternately from their orbits 500km above the Earth, Wu said. By 2022, “the three huge mirrors will divide the 360-degree orbital plane, realizing illuminating an area for 24 hours continuously”.
The real question is should it be done?

Astronomers and the anti-space junk community would no doubt be horrified. They’re still reeling at plans by artist Trevor Paglen to send a 33-metre reflective obelisk into orbit via a
SpaceX rocket later this year, claiming it’s a danger and “the space equivalent of someone putting a neon advertising billboard right outside your bedroom window”.
But while the “Orbital Reflector” will rival the Big Dipper for brightness, it will burn up within a couple of months.

John Barentine, Director of Public Policy at the International Dark-Sky Association, told Forbes the “solution” to Chengdu’s problems “potentially creates significant new environmental problems”.
“The Chengdu ‘artificial moon’ would have the effect of significantly increasing the nighttime brightness of an already light-polluted city, creating problems for both Chengdu’s residents, who are unable to screen out the unwanted light, as well as for the urban wildlife population that can’t simply go inside and close the shutters,” he said.
And if it sounds implausible, reflecting the Sun’s rays back to Earth at night has actually been done before.

In 1993, Russia successfully coaxed a beam 5km wide from a 20-metre solar mirror called Znamya 2 that was roughly as bright as a full moon. However, a piece of the reflective umbrella caught on an antenna as it was unfurling, and the satellite was deorbited after a couple of hours.