In 1868, a solar eclipse in India revealed a mysterious element in the Sun that would not be found on Earth for 27 years |
In August 1868, the Sun briefly became a laboratory for astronomers gathered in India to watch a total solar eclipse. Among them was the French astronomer Pierre Jules Janssen, who turned a spectroscope towards the bright prominences rising around the eclipsed solar disc. Their light contained a yellow spectral line that seemed to sit close…
