Musk’s first child by his first wife Justine Wilson died of SIDS in 2002 at 10 weeks of age. Mrs. Wilson bore him five more children, all boys and all consisting of twins and triplets.
The oldest of the Musk brood, the twins, are now in their teens and at least one wants nothing to do with their father.
18 years old Xavier Alexander Musk made a legal decision earlier this year to publicly disown Mr. Musk. Xavier filed for legal documents in April to change his name to Vivian Jenna Wilson and to change his legally recognized gender.
In a much-discussed legal filing, the Musk child wrote that his reasons for switching were, “Gender identity and the fact that I no longer live with or want to be related in any way to my biological father.”
Xavier has a twin brother, Griffin Musk, who has not sought public attention.
In 2006, three triplets were born.
Neuralink, the company Ms. Zilis works for, specializes in making brain interface technology. Although it has not yet begun human trials, it has reportedly conducted experiments where probes were inserted into rats’ heads and machines were able to decode electrical signals from the mammals’ brains.
Mr. Musk has long puzzled over US fertility rates after saying last year that “civilization will crumble” unless more children are born in America.
In another tweet on Thursday, Mr. Musk wrote: “Mars population is still zero people!”
His company SpaceX has long been linked with a potential private company mission to Mars, having previously advertised for people willing to take a one-way trip to the Red Planet.