Light caused by people is called artificial light. Artificial light that is not needed is called light pollution. Light pollution makes it hard to see the stars.
Photo Credit: Everlock/Getty Images
In the Know
Using Measurement Tools
Balance scales measure weight. Weight is how heavy something is. … read more
In the Know
How Do Communities Prepare for Snow Storms?
This big pile is road salt. It’s not like salt … read more
In the Know
Sports Around the World
Yukigassen started in Japan. It is like Capture the Flag. … read more