Desk Report: A study of pictures of Earth by night has revealed that artificial light is growing brighter and more extensive every year.
Between 2012 and 2016, the planet's artificially lit outdoor area grew by more than 2% per year.
Scientists say a "loss of night" in many countries is having negative consequences for "flora, fauna, and human well-being".
A team published the findings in the journal Science Advances.
Their study used data from a Nasa satellite radiometer - a device designed specifically to measure the brightness of night-time light.
It showed that changes in brightness over time varied greatly by country. Some of the world's "brightest nations", such as the US and Spain, remained the same. Most nations in South America, Africa and Asia grew brighter.
Only a few countries showed a decrease in brightness, such as Yemen and Syria - both experiencing warfare.
The nocturnal satellite images - of glowing coastlines and spider-like city networks - look quite beautiful but artificial lighting has unintended consequences for human health and the environment.
risingbd/Dhaka/Nov 23, 2017/Nasim