On August 18, 1868, French astronomer Jules Janssen observed a mysterious yellow spectral line during a solar eclipse. That line? It wasn't hydrogen—it was helium, a completely new element, first discovered in the Sun before it was ever found on Earth.
Helium now plays a critical role in cooling systems for nuclear reactors, MRI machines, and even in fusion energy research. What started as a celestial curiosity turned into a key player in energy innovation.
