What is the whole point? To get outside under the stars and raise public awareness of the impact of light pollution. From their website:
Light pollution threatens not only our “right to starlight”, but can affect energy consumption, wildlife and health. The GLOBE at Night campaign has run for two weeks each winter/spring for the last six years. People in 115 countries have contributed 66,000 measurements, making GLOBE at Night one of the most successful light pollution awareness campaigns.
I will be observing and reporting nightly. How about you?