Solar Eclipse on April 8 Shines a Light on Heliophysics, Outreach

Artist's rendition of a total solar eclipse. Image credit: Canadian Space Agency.

The upcoming April 8 total solar eclipse, which includes a part of Canada, may be an opportunity to introduce people to the wonders of the sun.

Sarah Gallagher, a professor at Western University who studies extragalactic astrophysics, told SpaceQ that she has been regularly speaking with media and students about the upcoming event to share more about solar science and how to (safely) observe with tools like eclipse glasses. Alongside that, she’s witnessing “lots of universities and science centers that are investing a lot of effort into sharing this experience with the public, and especially with kids.”

The eclipse, she noted, is one of those moments where people can break out of their normal routines – and that’s true of the mindset even of researchers, who often look to the practical aspects of their work instead of “sharing the wonder.”

“Sometimes we get caught in the kind of nuts and bolts of, ‘I’m learning this because it’s very practical and useful.’ But it’s also really cool, and it’s extraordinary,” she added of watching the eclipse. “That’s what I want people to go and see – the total solar eclipse –because it’s awesome, in that really literal way. We need to remember that we live in an awesome universe.”

Aside from the pure wonder of seeing darkness during the day, unusual lighting conditions in the sky and the sun’s corona, the solar eclipse also provides an opportunity to talk about how the sun is a great laboratory for heliophysics research. The sun is, naturally, the closest star to Earth and is only 150 million kilometers away from us. Compare that with the Alpha Centauri system at a far more distant four light years, and you can see why examining the sun up close is helpful to draw analogies with stars that are further away from us.

“Observing – we can do that in amazing detail, because we can use any kind of telescope. There’s a bunch of telescopes in space, as well as telescopes on the Earth, that observe the sun every single day,” Gallagher said. These satellites often look at the “space weather” that the sun brings to our Earth, which covers aspects including the solar wind, the charged particles that can affect satellite communications, and auroras that can also arise from the charged particles.

Gallagher noted that the sun can affect Canadians in ways that we would not expect – like running currents through pipelines. “When you have charged particles interacting in the Earth’s magnetic field, they can induce currents on the ground,” she said. “With pipelines, you have got giant pieces of metal that stretch across thousands of kilometres. If you have current through them, it can it affect – for example – how quickly they corrode.”

The electrical grid can also be vulnerable to solar activity, as Quebec experienced in 1989. Its grid was blacked out for nine hours after the sun triggered strong voltage fluctuations in the transmission grid, according to Hydro-Québec. The electricity provider created a task force after the event to “propose corrective measures,” among them increasing the “trip level” for the grid, creating a real-time alert system that shows operators where the grid is under stress, and changing operating procedures to reduce power flow if the grid is disturbed, among other measures.

The sun, by coincidence, is once again around the peak of its 11-year cycle of activity as the solar eclipse darkens our skies next week. Its photosphere – “surface,” simply put – is dotted with sunspots; these are hubs of magnetic fields that can induce activity. The sun has also been shooting off a lot of flares and coronal mass ejections of charged particles in recent months. It’s very possible that folks will see a very active corona, or upper atmosphere, as the moon briefly covers the face of the sun.

Aside from the space weather aspect, however, studying the sun brings other benefits to the understanding of stars. Seismic activities, magnetic fields, sunspot formation and the physics of stars more generally are all fields that benefit with regular examinations of the sun, Gallagher said. “It’s a very complicated system that we’re able to study in detail, because it’s here.”

The sun also plays into larger questions about our planet – such as how and when life arose, Gallagher said. Thousands of exoplanets have been tracked down using observatories like the now-retired NASA Kepler telescope. As humans, we often gravitate to searches for potentially life-friendly worlds.

While we imagine the sun as being a “typical” star, on the scale of the universe it is brighter than the average, Gallagher said. But given it’s so close by, it can serve as a useful “calibrator” to understand how life might arise on planets like ours elsewhere in the galaxy.

Studies of red dwarfs, a common type of star in our universe that are slightly smaller than our sun, show mixed results for habitability. On the one hand, they do provide enough energy to in theory, allow for liquid water on nearby rocky planets. On the other hand, they tend to flare a lot and bathe their solar systems in deadly radiation.

Young stars in general tend to flare a lot, so Gallagher said there is a lot of active research to look at different types to understand their level of activity. “When I talk about activity, I’m talking about how strong are their magnetic fields, how many solar flares do they have, and that sort of thing. That can affect what the environment around the stars are like, and how hospitable it is to allowing life to happen on planets around other stars.”

About Elizabeth Howell

Is SpaceQ's Associate Editor as well as a business and science reporter, researcher and consultant. She recently received her Ph.D. from the University of North Dakota and is communications Instructor instructor at Algonquin College.

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