The Musk acolyte protecting Earth from city-killing asteroids

Asked what people should do if astronomers identified a “city-killer” asteroid on a collision course for the United States, Nasa’s best advice was far from reassuring.

“Pray,” said Charles Bolden, the head of the space agency.

Over recent weeks, scientists have been warily scanning the night’s sky for evidence of YR4 – an asteroid 90 metres in diameter that experts feared had a very real risk of hitting our planet in 2032.

Fortunately, the possibility of a cataclysmic impact from the rock was dramatically reduced last week.

The risk of YR4 hitting Earth is now just a vanishingly small 0.004pc, according to Nasa. But the threat of a future collision with our planet that causes millions of casualties is still being taken deadly seriously by the space industry.

In fact, for more than two decades, Nasa has been standing up Earth’s planetary defence capabilities, working with space agencies and astronomers around the world.

In 1994, Nasa was ordered to catalogue all asteroids measuring more than 1km, and in 2005 this was extended to objects of more than 140m in diameter.

The task of protecting Earth from these fragments – leftovers from the creation of the solar system 4.6bn years ago – now falls to Jared Isaacman, a private astronaut and billionaire ally of Elon Musk who has been lined up by Donald Trump to lead Nasa.

At the time of Bolden’s advice to Congress in 2013, the space agency had identified 95pc of all asteroids with the potential to destroy human civilisation, but just a tiny fraction of so-called “city-killer” asteroids – of which there are more than 25,000 – that are smaller and more difficult to track.

That year, Earth came close to disaster when an asteroid exploded over the Russian city of Chelyabinsk, injuring 1,500 people.

Nasa now houses the Planetary Defence Coordination Office, set up in 2016 amid concerns that the US was failing to properly track the most dangerous “near-Earth objects”. Scientists have currently mapped about half of the space rocks deemed to have the potential to level a city.

Isaacman, who has not yet been confirmed as Nasa administrator, has said not enough is being done to protect Earth from such threats.

“Planetary defence against NEO threats seems disproportionately underfunded relative to the likelihood and magnitude of the associated risks [and] consequences,” he said on X.

At one stage, scientists gave the YR4 a 3.1pc chance of hitting Earth. Some of their analysis suggested this risk could rise as high as 20pc.

It received a ranking of three on the “Torino scale”, which ranks high-risk space objects – only the second asteroid to achieve such a ranking. Now they believe it is more likely to hit the Moon.

Astronomy experts argue the near-miss should serve as a wake-up call to bolster Earth’s defences and monitoring capabilities.

“It is a reminder that there are a lot of these objects out there,” says Robert Massey, of the Royal Astronomical Society. “Someday, something like this will hit us.”

A recent Nasa wargaming exercise to assess the readiness of America and its allies to deflect a hypothetical asteroid strike in 2038 warned the world had “limited readiness to quickly implement needed space missions” to respond to a collision risk.

Isaacman, 42, joins Nasa in the midst of job cuts, delays to its Moon programme and problems with its flagship rocket project.

He also faces competing priorities, with Musk pushing for Nasa to skip a planned Moon landing, which he called a “distraction”, and instead push on for Mars. Nasa’s previous planetary defence work has at times struggled for funding.

A former fintech entrepreneur, Isaacman is a government outsider. He founded Shift4 Payments in 1999, aged just 16. The business is now worth $8bn (£6.3bn).

He also has a reputation as something of a daredevil, owning the world’s largest fleet of private fighter jets and personally flying his Soviet-era Mig in air shows as the Black Diamond Jet Team.

Part of his estimated $1.9bn fortune he has used to fund private space missions, commanding a SpaceX mission in 2021 and a second flight in 2024. Perhaps unusually for a Musk acolyte, his political record includes substantial donations to the Democratic Party as recently as last year.

Chris Quilty, the founder of analyst firm Quilty Space, says Isaacman is viewed as “very pro-commercial in his approach – and he obviously has close ties to SpaceX”.

His appointment has been viewed positively by industry, Quilty says, although he notes that some major Nasa contractors – rivals to SpaceX – will be “less enthusiastic about his future stewardship”.

Isaacman has openly criticised Nasa’s funding for its Space Launch System programme, which is backed by Boeing. At a cost of $24bn, the rocket is integral to Nasa’s plan to return to the Moon, but Musk is widely believed to want the project scrapped. SpaceX’s own Starship and Superheavy rockets could be beneficiaries.

When it comes to planetary defence, SpaceX has so far been the primary launch partner for testing Earth’s readiness for a future Armageddon-style scenario.

Luckily, humanity has already proved that it is possible to alter the course of an asteroid while it is still millions of miles from Earth.

In 2019, Nasa launched its Double Asteroid Redirection Test – or Dart – aboard a SpaceX Falcon 9 rocket.

On Sept 26 2022, a probe weighing 500kg collided at 14,000mph with Dimorphos, a 177-metre-long asteroid. The impact was enough to substantially alter the rock’s orbit, providing a blueprint for a future deflection mission.

But such a mission can only be a success if we can see what is hurtling through space towards us – and a dangerous rock may need to be detected years, not months or weeks, before its potential impact with Earth to give the world time to prepare countermeasures.

Already, a network of global observatories keep an eye on the heavens for dangerous asteroids. The US, meanwhile, has funded a $1.9bn observatory in Chile, intended to map the night’s sky in extreme detail.

And, in 2027, SpaceX will launch Nasa’s $600m Near-Earth Object Surveyor mission, a satellite that uses infrared to spot asteroids. It is expected it will help the agency reach its target of tracking down 90pc of all dangerous space rocks.

The launch contract was awarded this week and the mission will take place under Isaacman – who called it an “important programme” – 20 years after it was first proposed after years of delays and a long struggle to secure funding.

Lord Dover, senior technical officer at Bayfordbury Observatory, says these projects should offer a “huge improvement” in the world’s ability to detect threats.

“The earlier we can discover a potential impactor, the sooner we can act,” he says.

In the aftermath of the YR4 scare, Nasa said the asteroid had provided an “invaluable opportunity for experts at Nasa and its partner institutions to test planetary defence science and notification processes”.

On his announcement as Trump’s preferred candidate to lead Nasa, Isaacman said space exploration, including reaching Mars, would “enable humanity to survive beyond Earth” and serve as a “hedge against catastrophic events that have shaped our planet’s past and will inevitably happen again”.

But it is the upcoming planetary defence missions Isaacman will oversee that could prove crucial to protecting a space-faring human race for decades to come.