Chengdu, the capital of Sichuan province, is the target for the extra light. The city has a population of 14 million.

The satellite is expected to be 500 kilometers (310 miles) above the surface of Earth. Scientists say that the artificial moon will be up to eight times brighter than Earth's Moon simply because it is much closer. The Moon is 380,000 kilometers (236,000 miles) from Earth.

The satellite will be coated so that it reflects sunlight back to Earth, in the same way that the Moon does. Scientists say that, during normal operation, it will be one-fifth as bright as a streetlight. Luminosity can be adjusted, or the brightness can be turned completely down, scientists said.

Chinese officials hope to illuminate 50 square kilometers (19 square miles) so as to save 1.2 billion yuan ($174 million) annually on electricity by removing unneeded streetlights. Wu Chunfeng, head of the Tian Fu New Area Science Society, said that the satellite would be in orbit by 2020 and that up to three more might be launched by 2022. Scientists also said that the moons could be moved as needed–to provide extra light during a blackout, for example.