GLOBE at Night

  1. Use the Globe at Night website to help find your constellation in the night sky.
  2. Use the Globe at Night website to find the latitude and longitude of the location where you are making your observation.
  3. Go outside more than an hour after sunset (8-10 pm local time). The Moon should not be up. Let your eyes become used to the dark for 10 minutes before your first observation.
  4. Match your observation to one of 7 magnitude charts and note the amount of cloud cover.
  5. Report the date, time, location (latitude/longitude), the chart you chose, and the amount of cloud cover at the time of observation. Make more observations from other locations, if possible. Compare your observation to thousands around the world!:

Globe at Night 2020 Dates and Constellations

New for 2020: During many of the 2020 Globe at Night campaigns there will be more than one choice for which constellation is optimal to use. This will depend on your location around the globe. To decide which one is best for you at your location for the dates listed below, check to see if the constellation is more than halfway above the horizon. If so, you can use that constellation for the campaign. If not, try another suggested constellation for that month.

Note: if possible, use Orion during the month of February and March as there is a special project being conducted which needs the help of Globe at Night citizen scientists. As LED lights increasingly replace older technologies for outdoor lighting, astronomers are left asking whether the night sky is getting brighter or darker as a result. While they can measure changes at professional observatories, understanding what’s going on in backyards around the world is a lot harder, and they’re turning to the public for help. Starting with Valentine’s Day in February and Pi Day in March, Globe at Night is asking people to take part in the “Globe at Night” project a few times during both 10-day campaigns. We will be comparing your measurements of Orion with those taken in February and March 2011 and 2012. So, if possible, please use Orion.


Those dates are:

Southern Constellations


January 16-15, 2020




February 14-23, March 14-24, 2020


Canis Major




April 14-23, May 14-23, 2020




June 13-22, 2020




July 12-21, 2020




August 10-19, 2020




September 9-18, 2020




October 8-17, November 7-16, 2020




December 6-15, 2020


GLOBE at Night is a citizen science project to record the brightness of the night sky around the world which began in 2006. The data is collected to produce an interactive map of all worldwide observations.

The Globe at Night program is an international citizen-science campaign to raise public awareness of the impact of light pollution by inviting citizen-scientists to measure their night sky brightness and submit their observations from a computer or smart phone. Light pollution threatens not only our “right to starlight”, but can affect energy consumption, wildlife and health. More than 100,000 measurements have been contributed from people in 115 countries during the campaigns each winter/spring over the last 9 years, making Globe at Night the most successful light pollution awareness campaign to date!

Explore the last 10 years of data in our interactive data map, or see how your city did with our regional map generator. The Globe at Night website is easy to use, comprehensive and holds an abundance of background information. The database is usable for comparisons with a variety of other databases, like how light pollution affects the foraging habits of bats.

Make a difference and join the GLOBE at Night campaign!

Data from 2018

History of this Event

BMOM has supported this event since 2014.