Elon Musk and Grimes, known for their unconventional approaches, have embraced parenthood in a rather unique fashion, as seen in the names of their children. Among them are Exa Dark Sideræl Musk and Techno Mechanicus Musk, whose intriguing names reflect the couple’s fascination with technology and the cosmos.

In a candid 2022 interview with Vanity Fair, Grimes disclosed that she and Elon Musk had quietly welcomed their baby girl, Exa, into the world through surrogacy. This revelation shed light on the couple’s penchant for privacy when it comes to their family life.

Grimes explained the significance behind their daughter’s name, saying, “Exa is a nod to the computing term exaFLOPS, which denotes the ability to perform a staggering one quintillion floating-point operations per second.” She further elaborated that “Dark” represents the unknown, a concept often misinterpreted with fear. “In truth, it’s simply the absence of photons, a beautiful mystery akin to dark matter that shapes our universe,” she mused.

The name Sideræl, pronounced “sigh-deer-ee-el,” carries its own celestial significance. Grimes described it as “the true time of the universe, star time, deep space time, not our relative earth time.” This choice also honors her favorite character from Lord of the Rings, Galadriel, who famously chooses to forgo the power of the ring.

According to Walter Isaacson’s biography, Elon Musk, Exa was born in December 2021, further highlighting the couple’s preference for a life somewhat shielded from the public eye. Their distinctive naming choices continue to captivate and spark conversations about the intersection of technology, science, and personal identity.

The book also stated that around Father’s Day 2022, the on-again, off-again couple welcomed a child named Techno Mechanicus, nicknamed Tau, also via surrogate. The biography includes a photo, dated June 2022, of Elon feeding the baby boy.

Though Grimes would prefer other salient details be kept private. “I have tried begging the public and my kids dad to keep them offline, and I’ve tried legal recourse,” she shared on social media in 2025. “The state of my children’s lives being public is of grave concern to me and I think about how to solve this every day. It’s insane to me that theres no way to deal with this.”