Exa Dark Sideræl Musk

Exa Dark Sideræl Musk was born via surrogate in December 2021 to Elon Musk and Grimes. The name was revealed by Grimes in a Vanity Fair profile in March 2022. 'Exa' references exaFLOP computational power; 'Dark' refers to the unknown of dark matter and dark energy ('the great mysteries of the universe'); 'Sideræl' (from sidereal, relating to distant stars) was also the name of a character in a Banks novel beloved by Grimes. She is affectionately called 'Y' by her parents — following the pattern of sibling X. Her birth was kept private for several months after it occurred.