Experiencing the total solar eclipse without sight

Solar eclipses are usually described in visual terms: The Moon moves in front of the Sun, the sky darkens, and the Sun’s wispy, white corona appears.

That’s how most people will experience the total solar eclipse on April 8, 2024. The majority of North America will see a partial solar eclipse, and for those in a narrow strip known as the path of totality, the Moon will completely blot out the Sun for a few minutes.

For people with blindness or low vision, the eclipse can also be experienced without sight. New technologies, projects, and resources aim to make this year’s eclipse more inclusive, helping as many people as possible experience this extraordinary cosmic event.

LightSound

A small, handheld device will allow people to experience the eclipse through sound instead of light.

Created by Harvard astronomer Allyson Bieryla, LightSound is a small box that converts light levels into sound through a process called sonification. A sensor records the amount of light coming from the Sun and outputs a corresponding sound through an audio jack that can be connected to headphones or a speaker.

When the Sun is unobstructed, LightSound emits a high-pitched tone. As the Moon covers the Sun, the tone decreases, ending at a series of clicks when the Sun is blocked completely. As the Moon slides off the Sun, the tone gradually increases back to the original pitch.

Bieryla got the idea for LightSound when she was reviewing student lab accessibility as the manager of Harvard’s Astronomy Lab and Clay Telescope in 2017. She had a discussion with Wanda Díaz-Merced, a blind astronomer who uses sonification to study astronomical data sets.

“We wanted to create something low-cost and easy to make, to give the blind and low-vision community a way to experience the eclipse through sound,” Bieryla said.

Díaz-Merced experienced her first eclipse in the 1990s, when she still had partial vision. As the sky began to darken, she remembers noticing what was happening through senses other than sight.

“I felt it on my skin, I felt it through my ears, I felt it through all the senses I had available, because life gave me the opportunity to pay attention in a different way,” she said.

Bieryla’s team developed a LightSound prototype for the 2017 total solar eclipse and has been refining it ever since. The design is open source, and the team shipped out free units that they built themselves or produced through workshops where participants learn how to solder electronic components. They produced around 900 devices for the 2024 total solar eclipse.

“We've been humbled by how many requests we have gotten for these devices, and the enormous amount of thanks from people and organizers for creating this tool,” Bieryla said. “I hope this project impacts people in a positive way and inspires a few new budding astronomers.”

Learning about eclipses

For the past two decades, NASA has been producing and distributing braille books to schools and institutions that support people who are blind or have low vision. These limited edition, handmade books allow people to use touch to discover everything from lunar craters to solar eclipses.

The agency’s “Getting a Feel for Eclipses” book explains how eclipses work and uses tactile graphics to show the alignment of the Sun, Moon, and Earth. Readers can also trace the path of totality as it crosses the United States.

Eclipse Soundscapes

Another way to experience the eclipse through senses other than sight is Eclipse Soundscapes, a NASA citizen science project.

Eclipse Soundscapes will study the impact of the eclipse on the environment through multisensory observations. It builds on a study from a 1932 eclipse in which the public was asked to observe animal and insect behavior and report their observations to scientists.

Participants can use all of their available senses to document what happens during the eclipse, collect data using a specialized recording device called AudioMoth, and help analyze data after the eclipse. The Eclipse Soundscapes smartphone app includes audio descriptions and haptic feedback to teach people about eclipses, and the AudioMoth recording device has tactile cues to assist people with blindness or low vision.

“We have intentionally made this project as inclusive and accessible as possible so that people who are blind or low-vision can participate alongside their sighted peers,” said Kelsey Perrett, a representative for the project. “Eclipses are amazing events, and we want everyone to be able to experience the eclipse and participate in this exciting opportunity to gather research.”

Nearly 700 people have signed up to be eclipse observers, and about 1,000 people have signed up to be data collectors. The Eclipse Soundscapes and LightSound projects will help turn what is usually thought of as a visual event into a multisensory experience.

“It was a fun project,” said Karl Smith, who participated in a trial run of the Soundscapes project during the 2023 annular eclipse. “I just really enjoyed participating. Who thinks of blind people in astronomy?”