The best spots to see next month’s solar eclipse will enjoy about two and a half minutes of totality. At least, on the ground. One team of NASA-funded scientists will stretch totality nearly three times longer at over seven minutes. While we’re watching the show from the ground, these scientists will be gathering observations from the air.
A pair of retrofitted WB-57F jets will catch up with the moon’s shadow 50,000 feet above Missouri and follow it through Illinois and Tennessee. Here, scientists will have a rare opportunity to conduct extended observations of the sun’s atmosphere.
Two telescopes are mounted in the nose of each plane. And will capture high-resolution images at 30 times per second.
“These could well turn out to be the best ever observations of high frequency phenomena in the corona,” says Dan Seaton, co-investigator of the project. “Extending the observing time and going to very high altitude might allow us to see a few events or track waves that would be essentially invisible in just two minutes of observations from the ground.”
Scientists are trying to figure out why the Sun’s atmosphere is so scorching hot. Our star’s corona spikes to temperatures reaching millions of degrees while lower atmospheric layers are much cooler at just a few thousand degrees. Still scorching, but nowhere near the extremes observed in the corona.
Why does this happen? Scientists have a couple of ideas. One theory centers around magnetic waves called Alfvén waves. These waves are believed to transport energy into the Sun’s outer atmosphere where it dissipates as heat. Nanoflares are another idea. Too small to detect individually, but numerous enough that a combined effect could release heat into the corona.
“We see evidence of nanoflare heating, but we don’t know where they occur,” says Amir Caspi, leader of the team. “If they occur higher up in the corona, we might expect to see waves moving downwards, as the little explosions occur and collectively reconfigure the magnetic fields.”
Observing the solar eclipse from a plane means more than just longer observations. At 50,000 feet, the sky is up to 30 times darker than it is from the ground. Plus, the two jets are above 50,000 feet worth of atmospheric disturbances. Which means much better image quality.
A bonus Mercury observation
The total solar eclipse is the big show, but scientists also plan to take a look at Mercury. 30 minutes before and after totality, the telescopes will be trained on Mercury. Infrared images will be captured in the first try to map the variations in temperature across the planet’s surface.
Mercury sits closest to the Sun, but that doesn’t mean the entire surface bakes. The day side does at about 800 degrees Fahrenheit. But the night side cools to a few hundred degrees below zero. The series of images will show how quickly the night side cools as Mercury rotates once every 59 Earth days.
According to NASA, scientists can use the data to figure out what the soil is made of and how dense it is.
Scientists will also scour through the images looking for a theorized family of asteroids called vulcanoids. These space rocks are believed to orbit between the Sun and Mercury.
And all of these observations are just one study funded by NASA. The space agency is funding 11 of them. Six will focus on the Sun. Five will study how the eclipse affects Earth.
As for me? I’m crossing my fingers for clear weather and will probably take a day trip to north Georgia to get a glimpse of totality.