Canadian musician and artist Grimes unintentionally announced the birth of her second child with Tesla co-founder and CEO Elon Musk via surrogate.

In an exclusive interview with Vanity Fair, Grimes said the baby girl, named Exa Dark Sideræl Musk (pronounced sigh-deer-ee-el), was born in December. The couple also refer to their daughter as “Y.” The new child’s name is complex, with Exa being a reference to exaFLOPS (or, the ability of supercomputers to perform 1 quintillion floating-point operations per second). Dark refers to the unknown and Sideræl is a “more elven” spelling of sidereal, the timekeeping system used by astronomers to locate celestial objects. Sideræl is also a reference to Grimes’ favourite Lord of the Rings character, Galadriel.


While conducting an interview at Grimes’ home in Austin, Texas, Vanity Fair reporter Devin Gordon heard the unmistakable sound of a baby crying. He knew the infant’s cry could not have been the couple’s first child, named X Æ A-12, who was born May 2020.