Light pollution is encroaching on observatories around the globe – making it harder for astronomers to study the cosmos

Lights from the city of Moscow reflect off the clouds above, illuminating the night in a bright glow.

This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights.

Outdoor lighting for buildings, roads and advertising can help people see in the dark of night, but many astronomers are growing increasingly concerned that these lights could be blinding us to the rest of the universe.