'The Great American Eclipse': a brief, dark scientific gold mine

On Monday, ‘The Great American Eclipse,' will cast darkness across 12 U.S. states. Canada will get a partial eclipse. Renowned astronomer Jay Pasachoff explains why this brief moment is so crucial for scientists.
Tourists watch the sun being blocked by the moon during a solar eclipse in the Australian outback town of Lyndhurst in 2002. (David Gray/Reuters)

On Monday, the moon will pass directly in front of the sun, cutting a narrow ribbon of darkness across the United States for the first time in 99 yearsViewers across Canada will experience a partial eclipse.

For anyone in or near the path of totality, the eclipse is a must-see spectacle. Over the next few days, hundreds of thousands of people are expected to descend on the parts of the U.S. where the total eclipse is visible.

For the scientists among them, it's a remarkable opportunity — and a rare one.

An annular solar eclipse is observed on May 21, 2012 in Tokyo, Japan. (Masashi Hara/Getty Images)
The next total solar eclipse won't take place until
July 2nd, 2019. And that one will only be visible in Chile and Argentina.

Renowned astronomer Jay Pasachoff has a prime spot in the path of totality. He and his team, including eight graduate students, are set up in Salem Oregon, where the elevation and clear forecast offer the best chance to take advantage of the small window.

Pasachoff is the director of the Hopkins Observatory and an astronomy professor at Williams College. He's also the chair of the working group on solar eclipses with the International Astronomical Union.

He's seen 65 solar eclipses so far. And he's pretty sure that's more than anybody else on the planet.

We asked Pasachoff to give us a rundown of just how important this eclipse is to scientists — in two minutes or less. Here's what he had to say, in a nutshell:

"If I were a researcher in the human heart, a cardiologist, and somebody told me that I could look inside a human heart, but only for two minutes and only if I went to South Africa to see it, I would go. And I would bring whatever instruments I could get on the plane with me.

And if a year and a half or two years later, somebody said, 'Alright, you've got another chance to see the heart. And it's a different person, so it'll look different, and the person's a little older. But you can look in again for two or three minutes.' Would I go? Of course I would go.

This is the only time we can see the solar corona like this, so we want to do everything we can in that time. And if that means looking for two minutes every two years, then that's what we have to do. There's tremendous interest when there's an eclipse in your country. And this time it's our turn, so we have a lot of observations going on across the country.

Artist's rendition of a total solar eclipse. (Canadian Space Agency)

I'm involved with something called the 'mega movie,' where we invite people to send in observations to a central place. That's a kind of citizen science.

There's relatively little that's been formally published about how animals react to eclipses, although there are a lot of stories. So I hope we'll get some real video observations this time. One of my colleagues who lives near where I am in Salem, Ore. has some alpacas. So he's going to watch them every hour to see what happens, although maybe they'll be more intrigued by the people coming to see the eclipse than by the eclipse itself.

The sun is a very powerful neighbour. And total eclipse is the most fabulous thing that you can possibly see in your whole life. But you see it only if you're in the band of totality. If you're even a mile outside, you don't see the effect, and you won't even understand why the other people think it's special.

So you should be travelling into the band of totality, and you should be taking children of all ages with you because they could really be inspired by this wonderful thing that they have the chance to see on Aug. 21."

This transcript has been edited for clarity and length.

To hear Jay Pasachoff describe the eclipse, download our podcast or click the 'Listen' button at the top of this page.