- Citizen scientists track the eclipse from 68 observation sites
- Scientists can create artificial eclipses but a real eclipse allows for precise and detailed measurements
- First look at incomplete data set is available online
On August 21st many of us stood outside and marveled at the solar eclipse.
But for some, the eclipse was more than just a show. It was an opportunity to participate in the National Solar Observatory (NSO) Citizen Continental-America Telescopic Eclipse (CATE) Experiment.
The Citizen CATE Experiment is funded by federal, corporate and private sources, including several companies that donated equipment to the project. Volunteer observers and schools get to keep the equipment used in the study.
A grand experiment
Scientists, students, and volunteers assembled along the 2,500-mile path of eclipse totality tracked the sun using 68 identical telescopes.
Using specialized software and instrument packages they produced more than 1,000 images from the start of the partial solar eclipse until totality.
The goal was to capture 90 minutes of continuous, high-resolution, rapid-cadence images detailing a difficult-to-capture region of the solar atmosphere: The sun’s inner corona.
This is the first time scientists have collected research-quality observations of the corona during the eclipse's entire transit across the US.
“This dataset is extraordinary,” says Matt Penn, principal investigator for the project.
“Normally during a solar eclipse, we get about 2 minutes of data in the region closest to the photosphere. But Citizen CATE allows us to get an hour and a half of data.”
My corona
The corona is the sun’s outer atmosphere. It is difficult for scientists to study because the photosphere, or solar surface, is so bright that it overpowers the faint corona. We can only see the corona when something obscures the photosphere.
(Think of a light so bright that it makes it difficult to see an object close to you. Blocking the light with your hand allows a better view of the object.)
Scientists can create artificial eclipses using an instrument called a coronagraph that covers the sun’s bright disk. The proximity of the instrument to the observor distorts the sun’s edge, making precise observation and measurement difficult.
During a real eclipse, the moon blocks the sun. The moon’s great distance lets scientists measure and study the corona in greater detail.
The process
On the day of the event, skies were clear for 58 of the 68 observation sites.
Observers, spaced about 50 miles from each other, started observations when the moon's shadow appeared on their horizon. They captured images every 10 seconds during totality.
The rapid cadence of imagery along with a two arcsecond pixel resolution should help scientists understand the intensity of the corona over an extended period as well as the motions of prominences, coronal inflows, coronal mass ejections, and other active regions.
The next total solar eclipse in the United States will be April 8, 2024. The path of totality will begin in Texas, moving north from Mexico, and will exit the US via Maine.
Start making plans to join the next team of citizen scientists.
