Why does a total solar eclipse reveal the Sun’s corona?
Quick Answer
The Moon blocks the Sun’s bright surface, or photosphere, allowing the faint corona to become visible. The corona is normally hidden by glare because it is far dimmer than the Sun’s disk.
The Full Story
During a total solar eclipse, the Moon passes directly in front of the Sun and covers the photosphere, the bright visible surface. That drop in glare makes the outer atmosphere of the Sun, called the corona, visible to the naked eye. The corona is much hotter than the photosphere in a counterintuitive solar mystery, reaching millions of degrees. Eclipses have been crucial for studying the corona and were historically important in confirming solar and relativistic ideas. Famous eclipse observations in 1919 helped test general relativity by measuring starlight bending near the Sun.
Key Facts
YouTube Angle
Suggested video title for this topic:
"The Sun hides its atmosphere—until the Moon turns the lights off."