Simple seismology should have noticed it a century ago.
Eternals (comics) - Wikipedia
Who Are the Eternals in the MCU? - Inside the Magic
Superhero Academy 101: Celestials, Eternals, and Deviants - HobbyLark
The Complete History of the Celestials, the Deviants, and the Eternals
Eternals, Marvel Cinematic Universe Wiki
ETERNALS: Celestial Death Explained! Why Did Tiamut Sacrifice Himself?
Marvel's Eternals Ending Explained
Marvel's overstuffed space opera Eternals is a muddled mess
The Complete History of the Celestials, the Deviants, and the Eternals
Eternals (2021) (Comic Book) - TV Tropes
She-Hulk finally addresses Eternals' Celestials problem