the.com/light pollution
the reason your grandkids will need a plane ticket to see the milky way.
means excess artificial light that washes out the night sky and disrupts ecosystems, sleep, and stargazing.
from coined mid-20th century by astronomers watching city glow drown out telescope views; the international dark-sky movement formalized the term in the 1980s.
global exposureone third of humanity cannot see the milky way
wildlife tollkills millions of migrating birds yearly via disorientation
growth ratesky brightness rising about 10 percent annually
health linkdisrupts melatonin, linked to sleep and cancer risk
for instance
las vegas strip — visible from space, brighter than surrounding desert by 100x
skyglow over la — stars reduced to a few dozen visible, versus thousands naturally
flagstaff arizona — first international dark sky city, designated 2001
nasa earth at night — satellite maps show entire coastlines outlined in glow