science π Helium discovery during solar eclipse in 1868
On August 18, 1868, Pierre Jules CΓ©sar Janssen discovered helium while observing a total solar eclipse in India. Janssen used a spectroscope to analyze the sun's light, noticing an unknown bright yellow line during the event. Norman Lockyer independently confirmed this spectral line, naming the element helium after the sun god Helios. Thirteen years later, Luigi Palmieri found the first Earth evidence of helium in Mount Vesuvius lava. This finding highlighted spectroscopy's power and is crucial for modern space technology. π