This article is part of a special report on the total solar eclipse that will be visible from parts of the U.S., Mexico and Canada on April 8, 2024.
Humans are lucky to live on a planet whose sun and moon appear, from our perspective on the ground, the same size in the sky. Every year and a half, on average, our gray satellite slides in front of our friendly neighborhood star, completely blocking its light somewhere on Earth: voilà, total eclipse.
One such event will occur on April 8, 2024. This total eclipse will move across North America from Mexico to Canada, passing through parts of Texas, Oklahoma, Arkansas, Missouri, Illinois, Kentucky, Indiana, Ohio, Pennsylvania, New York State, Vermont, New Hampshire and Maine in between.
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
Millions of people in the U.S. will see the eclipse. But they can do more than just watch: they can participate. Because the eclipse will darken the doors of so many, it is a perfect opportunity for a form of inclusive, open-to-anybody research sometimes called “citizen science.” Below are four NASA-funded projects that eclipse chasers can sign up for in order to contribute to earthlings’ understanding of both the nearest star and our home planet.
SunSketcher
The SunSketcher app lets eclipse viewers do science on autopilot—which will help researchers pin down the sun’s precise shape—and get some artistic results in the process.
The sun’s shape may seem straightforward—a sphere!—but that answer leaves out some nuance. “It’s almost circular but not quite,” says Gordon Emslie, SunSketcher project lead and a professor at Western Kentucky University. Instead our star is actually a little squished, or oblate. Scientists can currently map the particulars of that oblateness on a 50-kilometer scale, but the goal of SunSketcher is to bring that measurement to within something more like a few kilometers of accuracy instead.
Credit: Katie Peek; Source: NASA (eclipse track data)
To enable that target, after the SunSketcher app is downloaded onto a smartphone, it will automatically snap shots during two parts of the eclipse when features called Baily’s beads appear. These phenomena happen just before and after totality. At these two moments, the sun shines between the lunar mountains and valleys, creating an effect that some also call the “diamond ring.” Each user’s phone will capture that ring or those beads (choose your metaphor) and will also record the precise spot on Earth from which the pictures were taken, thanks to GPS. “Then, when some Internet connection is established, it uploads all the pictures to us or for analysis,” Emslie says.
The app has been developed largely by students at Western Kentucky University, including those in the sciences, art, design, psychology and English. “We put a lot of effort into making this user friendly,” Emslie says. And it is. “You just need to have a phone and be willing to leave it alone for two or three minutes,” he says.
If you do, you’ll have contributed completely unique data from a specific place and time on this planet. From the many eclipse hounds’ images, the SunSketcher team can create a kind of conglomerate of sun images taken from different angles by participants in areas from Texas to Maine at slightly different times. That amalgamation will allow the team to measure the sun’s shape in better detail than ever before. But the science doesn’t stop there: the shape reveals more about what the solar interior is like because material flowing within the star is what morphs it. In turn, that information will let scientists figure out how the sun tugs on nearby planets—an investigation of gravity.
The team plans to release the app in late February and hopes that as many people will download it as possible. “Your data is valuable,” Emslie says. “It’s as simple as that.”
Eclipse Soundscapes
The Eclipse Soundscapes project, in contrast, focuses more on data related to Earth than the sun. And it focuses not on the typical visual data but instead on the other senses, particularly (as the name implies) sound. “If you search on Google Images for ‘scientist,’ it almost always comes up with someone who’s looking at something,” says MaryKay Severino of Advanced Research in Inclusion & STEAM Accessibility (ARISA) Lab, which is leading the project. When it conceptualized Eclipse Soundscapes, the team wanted to make science more multisensory and more inclusive of people often left out of astronomy.
There are multiple ways to participate in the project. One way that amateur scientists can join is by applying to be an “observer.” On the day of the eclipse, they’ll record observations of the world around them—even if they’re not on the eclipse path—using all of their senses and submit their take to the team. They can sign up online until just a few days before the eclipse.
Participants who sign up to be a “data collector,” meanwhile, will use recording devices called AudioMoths, which are equipped with wayfinding “bump dots” for blind and low-vision users, to capture sound. Data collectors must be on or near the eclipse path. Applications for free kits ended on January 31, but participants can build their own using supplies linked to on the website and just need to order them in time to Lego them together before April 8.
This idea behind Eclipse Soundscapes has a long legacy: it’s following up on a nearly 100-year-old study that also enlisted community participants and looked at how animals and insects react to eclipses. Trae Winter, who is co-leading the project and co-founded the lab with Severino, first came across the study after a blind friend asked him to describe an eclipse—and he remembered someone else recalling that when a previous eclipse came through, it was like someone turned on a “cricket switch” once it got dark during the day.
Today the researchers would like to re-create a more modern version of that 1930s study, and they need the help of lots of people all over the U.S. “You can’t just measure something in one habitat and say it’s universal,” Winter says.
Science enthusiasts can also analyze information from Soundscapes after the eclipse is over, provided they take an online training course. And if anyone just wants to learn about the eclipse, they can take on the role of Soundscape “apprentice” and do some asynchronous modules online. For all of the roles, the team provides official NASA certificates of completion that include the space agency’s logo.
HamSCI
Another project also involves hearing, rather than seeing, the eclipse—although this hearing requires the use of ham radios to collect more specialized data. It’s organized, appropriately, by a platform called the Ham Radio Science Citizen Investigation (HamSCI). The community is led by the University of Scranton’s department of physics and engineering, in collaboration with other universities and institutions.
Scranton professor Nathaniel Frissell originally started HamSCI to try to understand the upper atmosphere and the way it’s affected by solar activity. And although the eclipse is perhaps its most widespread effort, the group takes on lots of research projects. “We made it to encompass all sorts of scientific investigations that involve amateur radio,” he says.
During the eclipse, participants will be digging into the ionosphere, a part of Earth’s upper atmosphere that’s full of charged particles and reflects radio waves. It’s always in flux, and when charged particles and radiation from the sun hit it, they contribute to those changes.
Eclipse data for HamSCI will help scientists understand and better predict the ionosphere’s short-term shifts. Its fluctuations affect, of course, the atmosphere more broadly but also communications on Earth because radio signals often rely on this tempestuous region. The eclipse—when the solar behavior is pretty well known—is a great time to investigate the ionosphere’s sun-shifted dynamics. “It’s a really good opportunity to test our models and test our understanding. And if what we sense doesn’t match what our models say, then it gives us a chance to go back and say, ‘Well, well, why not?’” Frissell says.
Would-be community participants can pick from a couple of tracks to gather data toward that end. If they’ve never done anything with ham radio before, Frissell says, “probably the best way to participate in it is to join up with a local club,” which can offer equipment that can be used to participate in one of several HamSCI projects.
The other track involves building a radio receiver at home and tuning it, on the day of the eclipse, to a shortwave station called WWV, broadcast from Fort Collins, Colo. “You can hear that signal all over the United States—all over the continent,” Frissell says. It’s sent out at a very precise frequency, but the upper atmosphere’s activity shifts that frequency. “So any changes you see in the frequency measurement from this radio station can be attributed to variations in the ionosphere,” he says. Those tune changes show up immediately, an effect Frissell describes as “instant gratification.” And isn’t that what an eclipse is all about?
Eclipse Megamovie
The sun isn’t a blank, calm disk—as anyone who sees the corona during the eclipse will know firsthand. It’s got storms and spots and outbursts, among other things. And a crowdsourced science project called the Eclipse Megamovie aims to add more detail to, as its description says, “the secret lives of solar jets and plumes.” Those fiery features first spew forth from the sun and are then carried into space on the solar wind, a voyage that, like all journeys, causes them to change along the way.
The Eclipse Megamovie project enlists amateur scientists to find out what those features and their fickleness do as the cameras of these participants help pinpoint jets on their way out from a given star and plumes whose properties change.
All it takes to participate is a digital single-lens-reflex (DSLR) camera with a zoom lens and a tripod and willingness to point it in the right direction at the right time. After participants send pictures in, the scientists will use artificial intelligence to help analyze the images and identify the target features that they are looking for. Relatedly, coders can help develop the algorithms that will do that sifting.
The pictures will also be aligned together into a megamovie, as the name implies. And after the eclipse, working on the software that notches all the pictures into place is another way that people can join the effort. To participate, eclipse chasers can apply and upload a practice shot for the team.
Another project, called the Citizen Continental-America Telescopic Eclipse (CATE) 2024 experiment, is selecting about 35 teams to collaborate on a different movie. This one will use solar telescopes to take polarized observations of the sun’s corona as it evolves during the 60 minutes of the eclipse’s pass over North America. Those teams’ data will help reveal how the magnetic field and plasma are functioning to shed light on the corona's interconnections and heating mechanism.