Move away from a campfire, and as one might expect, the temperature will quickly drop. Move away from the sun’s surface, and the temperature quickly and inexplicably climbs to around two million degrees. No one knows why.
But a coast-to-coastwill give scientists a golden opportunity to probe the roots of the mystery and, perhaps, find some answers.
“Combining ground-based eclipse results with the observations from satellites in the visible, ultraviolet, X-ray and radio parts of the spectrum will provide theever seen,” noted astronomer Jay Pasachoff of Williams College writes in the August issue of Scientific American magazine.
“Some might find it disconcerting that, arguably the best studied of all celestial objects, is so incompletely understood. But I see the lingering questions as a wonderful excuse to share one of the greatest experiences in nature.”
Ninety-three million miles from Earth, the sun is enormous by any human standard with a diameter of 860,000 miles and the mass of 330,000 planet Earths. By volume, the sun could swallow 1.3 million Earths. The sun generates so much gravity that a 170-pound human would weigh about 4,600 pounds on the sun’s visible surface.
In the sun’s hellish core, which extends out to about a quarter of the sun’s diameter, the concentrated weight of the star creates enormous pressure and temperature — 27 million degrees Fahrenheit — enough to trigger nuclear fusion that consumes some 600 million tons of hydrogen per second.
It’s been doing that for the past five billion years, balancing the inward pull of gravity with the outward push of fusion energy in the core. And even though the sun is a relatively small,…