开云体育

FYI, an interesting article on a growing source of light pollution.? Best -- Michael

https://www.sciencemag.org/news/2021/03/study-finds-nowhere-earth-safe-satellite-light-pollution?utm_source=Nature+Briefing&utm_campaign=555a6b2124-briefing-dy-20210330&utm_medium=email&utm_term=0_c9dfd39373-555a6b2124-46027394