In Chengdu, there is reportedly an ambitious plan afoot for replacing the city’s streetlights: boosting the glow of the real moon with that of a more powerful fake one.
The south-western Chinese city plans to launch an illumination satellite in 2020. Scientists estimated that it could be eight times more luminous than the actual, original moon. It will also orbit much closer to Earth; about 500 km (310 miles) away, compared to the moon’s 380,000 km (236,000 miles).
The “dusk-like glow” of the satellite would be able to light an area with a diameter of 10-80km, while the precise illumination range could be controlled within tens of meters – enabling it to replace streetlights.
But the ambitious plan still wouldn’t “light up the entire night sky,” Wu Chunfeng, chief of the Tian Fu New Area Science Society, told China Daily. “Its expected brightness, in the eyes of humans, is around one-fifth of normal streetlights.”
Wu estimated that new moons could save the city of Chengdu around 1.2 billion yuan ($173 million) in electricity costs annually, and could even assist first responders during blackouts and natural disasters. If the project proves successful, it could be joined by three more additions to the night sky in 2022, he said.
But much more testing needs to be done, Wu said, to ensure the plan is viable and will not have a detrimental effect on the natural environment.
“We will only conduct our tests in an uninhabited desert, so our light beams will not interfere with any people or Earth-based space observation equipment,” he told the Daily.
The People’s Daily report credited the idea to “a French artist, who imagined hanging a necklace made of mirrors above the Earth which could reflect sunshine through the streets of Paris all year round”.
There are precedents for this moonage daydream rooted in science, though the technology and ambitions differ. In 2013 three large computer-controlled mirrors were installed above the Norwegian town of Rjukan to track the movement of the sun and reflect its rays down on the town square. “Rjukan – or at least, a small but vital part of Rjukan – is no longer stuck where the sun don’t shine,” reported the Guardian at the time.
Longer ago, in the 1990s, a team of Russian astronomers and engineers succeeded in launching a satellite into space to deflect sunlight back to Earth, briefly illuminating the night-time hemisphere.
The Znamya experiment was to “test the feasibility of illuminating points on Earth with light equivalent to that of several full moons”, the New York Times said. “Several” proved an overstatement, but the design was shown to be sound.
A more ambitious attempt, Znamya 2.5, was made in 1999, prompting preemptive concerns about light pollution disrupting nocturnal animals and astronomical observation. A spokesman for the technology ministry in Bonn was less concerned, telling the Guardian, “It’s a bit early for April Fool jokes but this sounds like one”.
But Znamya 2.5 misfired on launch and its creators failed to raise funding for another attempt.
The People’s Daily was quick to reassure those concerned about the fake moon’s impact on night-time wildlife.
It cited Kang Weimin, director of the Institute of Optics, School of Aerospace, Harbin Institute of Technology, who “explained that the light of the satellite is similar to a dusk-like glow, so it should not affect animals’ routines”.
sources: time.com, theguardian.com, nbcnews.com
