Elon Musk and Grimes have had another baby.
After a few complications with their first pregnancy — Grimes said she regularly collapsed towards the end of the third trimester and haemorrhaged at one point — the pair used a surrogate to deliver their second child, a daughter.
News of their second baby, born in December, was kept out of the public eye until journalist Devin Gordon interviewed Grimes at her home for Vanity Fair.
Her baby's cries could be clearly heard from another room so Grimes gave him a few details, which featured in Vanity Fair's April cover story.
What's the baby's name?
Initially, Grimes only referred to her daughter as Y.
But after Gordon also interviewed Musk, she later texted Gordon to reveal her full name: Exa Dark Sideræl Musk.
How do you pronounce that?
Exa, Dark and Musk are all fairly straightforward, but Sideræl?
Grimes sent Gordon a voice note of the pronunciation: "sigh-deer-ee-el".
What's the name mean?
- Exa — that's a reference to exaFLOPS (FLOPS is an acronym for floating-point operations per second), which is a supercomputer system capable of performing one quintillion operations per second. When we looked this up, we couldn't help but notice exaFLOPS gets abbreviated to E, which is what Grimes calls Musk
- Dark — which Grimes told Vanity Fair was a nod to the unknown, saying "dark matter is the beautiful mystery of our universe".
- Sideræl — this is actually a slight variation of the word sidereal, which is a timekeeping system based on distant stars instead of the Sun. Fun fact: a sidereal day is about four minutes shorter than a solar day. The spelling of this element of her name, Grimes says, is elven — a language created by The Lord of the Rings author J R R Tolkien.
Why do they call her Y?
That's not entirely clear, but it may have something to do with their son.
Born in 2020, the pair called him X Æ A-12, but had to tweak that slightly to X Æ A-Xii to fit in with California's naming and birth certificate requirements.
It's pronounced "X A.I. Archangel", but they call him X for short.
And X and Y form a pretty neat set, especially when you're thinking in terms of mathematical terms and symbols.
Sometimes, Vanity Fair reports, Musk and Grimes also use the nickname Sailor Mars for their daughter.
That's a reference to both the cartoon series Sailor Moon and Musk's grand plans to go to Mars.
We probably won't see Y any time soon
After the interview was published, Grimes tweeted a link praising the story and asking for people to respect her daughter's privacy.
"I’d love her to be able to live as private of a life as possible," she wrote.
"This is the last time I'll do any traditional press cuz I'm a pretty private person.
"Haven't done press in a long time cuz my personal life is so mad."
Wait, didn't Musk and Grimes split up?
In September last year, the New York Post's entertainment brand Page Six reported the pair had broken up.
"We are semi-separated but still love each other, see each other frequently and are on great terms," Musk told the newspaper.
But when Grimes was interviewed — her last conversation with the magazine was in late January — she said they were together but in a separate kind of way.
"I would probably refer to him as my boyfriend, but we're very fluid," she said.
"We just have our own thing going on and I don't expect other people to understand it."
But after the story was published, Grimes said things had changed.
"Me and E have broken up *again* since the writing of this article haha, but he’s my best friend and the love of my life," she tweeted.
