Scientists warn stars could be invisible within 20 years as light pollution brightens night skies

Scientists have warned that the ability of humans to see stars in the night sky could be wiped out in just 20 years because of light pollution.In 2016, astronomers reported that the Milky Way was no longer visible to a third of humanity and light pollution has worsened considerably since then. At its current rate most of the major constellations will be indecipherable in 20 years, it is estimated. The loss, culturally and scientifically, will be intense, according to (The Guardian).Research by physicist Christopher Kyba, of the German Centre for Geosciences has revealed that light pollution is now causing the night sky to brighten at a rate of around 10% a year, an increase that threatens to obliterate the sight of all but the most brilliant stars in a generation. A child born where 250 stars are visible at night today would only be able to see about 100 by the time they reach 18.The case against light pollution goes further. Bluish emissions of LEDs are almost entirely lacking any red or near infrared light, said Prof Robert Fosbury, of the Institute of Ophthalmology at University College London (UCL). "We are becoming starved of red and infra-red light and that has serious implications," he said. "When reddish light shines on our bodies, it stimulates mechanisms including those that break down high levels of sugar in the blood or boost melatonin production," he added."Since the introduction of fluorescent lighting and later LEDs, that part of the spectrum has been removed from artificial light and I think it is playing a part in the waves of obesity and rises in diabetes cases we see today," he said."The night sky is part of our environment and it would be a major deprivation if the next generation never got to see it," Astronomer Royal Martin Rees said.Nevertheless, the introduction of only a modest number of changes to lighting could make a considerable improvement. These moves would include ensuring outdoor lights are carefully shielded, point downwards, have limits placed on their brightness, and are not predominantly blue-white but have red and orange components.