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Globe At Night

Globe at Night is an international citizen-science campaign to raise public awareness of the impact of light pollution by inviting citizen-scientists to measure & submit their night sky brightness observations.


Can you find Perseus?

Perseus the slayer of Cetus is most easily seen rising in the East in the winter. The constellation is most easily identifiable as what almost appears to be a wishbone of brightest stars, with the brightest being the center and chest of Perseus. The legs of Perseus are pointing southward and are the forked part of the wishbone and the body and head are the straight line leading up northward. It is easy to find Perseus by either looking southward from Cassiopeia or just to the left of Taurus the Bull.

Visible in: Northern hemisphere


Can you find Grus?

To find Grus, look directly south. You will see four bright stars making their way from left to right in the sky. These stars also happen to line up in brightness order. The brightest one, Sirius, will be somewhat higher in the sky than the other three, and is the farthest to the left. The next one to the right is Canopus, then Achernar. The fourth one is found in the constellation Piscis Austrinus, and is called Fomalhaut. Grus is found between the Achernar and Fomalhaut, and is located about 15 degrees lower in the sky than a line drawn between those two stars. Look for a triangle formed by Grus’ three brightest stars (the third brightest star is actually two stars), the two dimmer stars in the triangle may appear red. The triangle forms the body of the crane with Grus’ neck stretching out to the West, and the wings to the North and South.

Visible in: Southern hemisphere


Join us for the December, 2023 campaign!

We are off to a great start this year with 20456 observations so far! Help us reach our goal of 20000 data points for 2023!
Observations from 2023
Goal for 2023
Total Observations

How to report data?

Practice finding all the Globe at Night Constellations, when you are done practicing follow the 6 steps:

Go Outside

During the campaign dates, 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.

Use App

Use a night sky app on your phone outside to find the constellation from where you are.

Open Form

Go to the Globe at Night Report page to start to enter Globe at Night measurements. Make sure you are in “Nighttime version”

Fill your location

With a smart phone, the app will put in the date, time, location (latitude/longitude) automatically. Otherwise please type them in. For your location, type the street address closest to your observation along with the city, state or province and country.

Choose the star

Choose the star chart that looks most closely to what you see toward your constellation. That is, what is the faintest star you can see in the sky and find in the chart?


Chose the amount of cloud cover at the time of observation and then click on the “SUBMIT DATA” button.
Resources for 2023

Resources for 2023

Globe at Night is truly an international campaign. Our Activity Guides, Postcards, and the data reporting webapp have been translated into many languages. These are all available to download from our Resources page.

Globe at Night Webapp

Globe at Night Webapp

Whether you use a smartphone, tablet or computer, you can submit your data in real time with our webapp - now available in 28 languages! Help us make 2021 a record year!

For Libraries

For Libraries

SciStarter and Arizona State University created a customizable citizen science kit with everything needed for patrons to engage in Globe at Night. Access all the materials and details at SciStarter.org/Library-Resources

See how your region is doing this year below. If you don't see very many data points, consider going outside tonight and contributing your own! Compare to other regions or previous years with our regional map generator.