Making Eclipse Observations

NOTE: The eclipse tool is not currently available in the GLOBE Observer app, but you can still make clouds observations any time. The eclipse features will next return for the total solar eclipse in South America on July 2nd, 2019.

How should I make observations during the eclipse?

First and foremost, make sure you are being safe when you are observing the eclipse. Looking directly at the Sun is unsafe except during the brief total phase of a solar eclipse (“totality”), when the moon entirely blocks the Sun’s bright face, which will happen only within the narrow path of totality. For more details about how to observe safely, including the appropriate type of eclipse glasses and filters to use, visit the NASA eclipse safety page.

Also, a total solar eclipse is an amazing experience, apart from the interesting science involved. Especially for first-time eclipse observers, we recommend you put down your phone or camera during the precious few minutes of totality itself and just enjoy the experience. The data collection procedures below take that into account, and ask you to make observations and measurements before and after totality, but not during totality itself.

Cloud Type and Cover

Three people observing the clouds.

The simplest way to participate without needing any additional equipment is by making clouds observations using the GLOBE Observer app. Clouds are an important part of the Earth's energy budget, and you may observe changes as the Sun becomes more and more blocked during the eclipse. We would like you to make regular observations for about two hours before and after the point of maximum eclipse. That will cover the period when the moon first starts blocking the Sun, called first contact, all the way to last contact, when the moon moves completely past the Sun and is no longer blocking any portion of it.

Try to make observations about every 15-30 minutes, more often if you wish, especially any time you notice something changing. If you are also measuring air temperature, the special eclipse page on the app will remind you with notifications to make your measurements about every third air temperature measurement. Feel free to add narrative comments to your photos about anything interesting you see happening.

Air Temperature

Hand holding thermometer

If you'd like to take it a step further and get a separate thermometer (anything from a simple liquid-filled thermometer to more complex digital models - see more about different types here), you can also collect and report data about air temperature on a special page that will be available in the GLOBE Observer app a few days before each future eclipse. Whatever type of thermometer you use, make sure you are taking your measurements in the shade, even if that is just the shadow of your body with the thermometer held at arm's length.

Here's the preferred schedule for air temperature measurements:

  • For two hours before and after maximum eclipse, take a measurement every ten minutes.
  • If you can, increase that to every five minutes for the half hour before and after totality or the maximum eclipse at your location.
  • You can also take measurements the day before the eclipse. Ideally, these would be near the time maximum eclipse will occur the following day. For example, if the time of totality for your location is 10:15 am on August 21st, make measurements at about 10:15 on August 20th.

Surface Temperature and Other Variables

There are many other atmospheric variables that could be interesting to observe, but won't have a designated place to enter via the GLOBE Observer app. For example, surface temperature using an infrared thermometer or wind speed and direction using an anemometer (wind speed gauge). These types of observations can always be noted in the comments of a cloud or air temperature measurement. For those willing to put in a bit of extra time to be trained in the GLOBE surface temperature protocol, acquire an infrared thermometer and set up an observation site, you can collect that data during the eclipse and report it through the GLOBE Data Entry app or via the online data entry form. You can find more information about the training requirements on the protocol eTraining page. To measure surface temperature, you will need to complete an introduction to GLOBE, an introduction to the atmosphere protocols generally, and then learn how to do the surface temperature protocol specifically. The training slides can be downloaded by anyone, but you will need to log in with your GLOBE Observer account information to take the short quizzes to get credit for the training and be able to enter data. Especially for educators, you may find the eclipse page on the GLOBE formal education website useful.

More Information and Other Citizen Science Projects During the Eclipse

For general information about eclipses, videos, and much more, visit the NASA eclipse website. The archive page from the 2017 eclipse in North America also has suggestions about how to observe the dimming of daylight, and other activities you can try before or after the eclipse. Apps such as iNaturalist or iSeeChange are also venues for reporting general observations of nature, during the eclipse or any time.