What Will the Sun's Corona Look Like During Totality?

On April 8th, the Moon will slowly cover the Sun's brilliant disk of light, casting much of North America at least in partial shadow. That shadow will be deeper along a narrow path stretching from the Pacific Ocean off the coast of Mazatlan, Mexico, crossing through Texas, Oklahoma, and Arkansas up through northern New York, Vermont, New Hampshire, and Maine, and finally on to the Canadian Maritimes. Only along this path of totality will the Sun's ethereal corona become visible.

Unlike the Sun's disk, which emits light along a spectrum that peaks at yellow-green wavelengths, the corona's light is a purer white, the photons coming from sunlight scattered off free-flowing electrons and dust in the Sun's outer atmosphere. (Even before totality begins, observers on the ground will notice the change in the quality of light, which becomes oddly silvery.)

Particles streaming off the surface of the Sun are constantly, albeit slowly, changing the shape of the solar corona. Scientists have long known that the shape of the corona during the 2017 eclipse, also visible across the U.S., would be different from the shape we'll see on April 8th. Seven years ago, the Sun's magnetic field was in the well-behaved dipole shape of a bar magnet, and the corona was primarily aligned along the Sun's equator. In 2024, however, the Sun's magnetic field is acting up, twisting and snapping in ways that allow the corona to be visible in spikes all around the Sun.

Now, Predictive Science Inc has released a live forecast for the shape of the corona that you can expect to see on April 8th if you are in the path of totality. In fact, the company even customizes the view you'll see from your location with an interactive map.

The corona will not be moving while you're watching — even though the solar wind streams outward at hundreds of miles per hour, the Sun is far away and the movement isn't noticeable over the few minutes of totality. This is the view Predictive Science, Inc, suggests viewers in Texas will see during totality as of April 3rd:

The prediction involves first using a computer model of the Sun, which accounts for the motions of hot plasma in a magnetic field. New for the 2024 eclipse, this model is updated in real-time with actual measurements of the surface magnetic field from NASA's Solar Dynamic Observatory.

Take a look at the prediction, then record your own observations to see how reality compares — and let us know in the comments below!