San Francisco (AFP) – Space conquest: check. Disrupt the auto industry: check. Take over Twitter? Why not. From eccentric entrepreneur to the world's richest man, Elon Musk likes to dream big — and these days, he is everywhere you look.

Two decades after banking his first millions, the South-African born Musk last year became the world's richest person — wresting the title from Amazon's Jeff Bezos — following the meteoric rise of Tesla, his electric automaker founded in 2003.

The billionaire's latest big splash: a bid announced Thursday to take over Twitter, capping a rollercoaster fortnight of announcements and counter-announcements — which Musk punctuated, characteristically, by gleefully firing tweets at the platform.

Just a week earlier, the 50-year-old was making headlines as Tesla cut the ribbon on a “gigafactory” the size of 100 soccer fields in Texas, where the firm is now based and Musk himself has relocated from California.

At the same time, his space transport firm SpaceX was breaking yet another boundary as a partner in a three-way venture to send the first fully private mission to the International Space Station.

Musk also makes news of a less flattering kind: Tesla has faced a series of lawsuits alleging discrimination and harassment against Black workers as well as sexual harassment.

In parallel with the whiplash-inducing stream of business news, Musk's controversy-courting persona — with an unrestrained Twitter style and penchant for living by his own rules in the private sphere too — keeps the gossip press busy.

It recently emerged Musk had had a second child with his on-again off-again partner, the musician Grimes: a girl they named Exa Dark Sideræl Musk — although the parents will mostly call her Y.

He is even expected to make an appearance — in person or not — at the celebrity defamation trial pitting Johnny Depp against his ex-wife Amber Heard, who formerly dated Musk.

But one way or another, Musk has become one of the most ubiquitous figures of the era. So how did he get where he is today?

To Mars… and beyond?

Born in Pretoria, on June 28, 1971, the son of an engineer father and a Canadian-born model mother, Musk left South Africa in his late teens to attend Queen's University in Ontario.

He transferred to the University of Pennsylvania after two years and earned bachelor's degrees in physics and business.

After graduating from the prestigious Ivy League school, Musk abandoned plans to pursue further studies at Stanford University.

Instead, he dropped out and started Zip2, a company that made online publishing software for the media industry.

He banked his first millions before the age of 30 when he sold Zip2 to US computer maker Compaq for more than $300 million in 1999.

Musk's next company, X.com, eventually merged with PayPal, the online payments firm bought by internet auction giant eBay for $1.5 billion in 2002.

After leaving PayPal, Musk embarked on a series of ever more ambitious ventures.

He founded SpaceX in 2002 — now serving as its chief executive officer and chief technology officer — and became the chairman of electric carmaker Tesla in 2004.

After some early crashes and near-misses, SpaceX perfected the art of landing booster engines on solid ground and ocean platforms, rendering them reusable, and late last year sent four tourists into space, on the first ever orbital mission with no professional astronauts on board.

Musk's jokingly-named The Boring Company is touting an ultra-fast “Hyperloop” rail transport system that would transport people at near supersonic speeds.

And Musk has said he wants to make humans an “interplanetary species” by establishing a colony of people living on the Mars.

To this end, SpaceX is developing a prototype rocket, Starship, which it envisages carrying crew and cargo to the Moon, Mars and beyond — with Musk saying he feels “confident” of an orbital test this year.

Musk, who holds US, Canadian and South African citizenship, has been married and divorced three times — once to the Canadian author Justine Wilson and twice to actress Talulah Riley. He has seven children. An eighth child died in infancy.

Forbes estimates Musk's current net worth at $265 billion.