Even just four months after the eclipse, scientists have learned a ton from the day the sun went out.
The event in the Earth's upper atmosphere had been theorized before, but never detected.
"It's like the eclipse shape was burned into her retina," a doctor said about one patient.
But solar eclipses have been known to affect temperature and wind.
ABC News anchor Frank Reynolds shared his hopes for 2017.
The first daughter is among those looking forward to Monday's event.
"Has Everyone His Smoked Glass Ready?" one local newspaper asked before the 1918 celestial event.
From how to protect your eyes on Monday to why ancient civilizations were spooked by the moon blacking out the sun in the middle of the day.