Scientists are understandably jazzed about the total solar eclipse on Aug. 21. They hope to learn a lot. But you should be excited, too, because the eclipse will pull back the curtains on one of the greatest and deadliest mysteries of the universe: the solar corona.
As a graduate student at Cornell, I came to know Hans Bethe, the brilliant nuclear physicist who in 1967 won the Nobel Prize for figuring out the nuclear fusion reactions that make the sun shine.
Basically, Bethe found that pairs of hydrogen nuclei fuse – like clay balls, they literally stick together – to create zillions of helium nuclei. The magic-like, nuclear transformations are explosive, releasing mind-boggling amounts of energy, as described in Albert Einstein’s famous equation: E = mc2.
It’s that energy – akin to 100 billion H-bombs detonating every second – that lights up the sun’s “photosphere.” That’s the yellow disk kids draw when depicting a sunny day.
During a total eclipse, the moon’s round shadow perfectly blots out the photosphere. The glaring brightness of the photosphere normally blinds us to the corona, which is the sun’s far-fainter, halo-like outer atmosphere.
Revealing the corona is worthy of great excitement, because the corona is arguably the most mysterious, most turbulent, most unpredictable, most deadly part of the sun.
The corona is where, for some weird reason, the sun’s temperature spikes – from 10,000 degrees to several million degrees Fahrenheit. It’s as if in stepping back from a fire there’s a point where it suddenly feels hotter, not cooler. Hundreds of times hotter!
For some unknown reason – science awaits the next Hans Bethe – the corona is also given to deadly tantrums. Without any warning, it…