A direct hit from an asteroid big enough to wipe out most life on Earth is unlikely, but European ministers need to decide whether it’s worth paying to be prepared.

Scientists this week are wargaming their response to a fictional asteroid hurtling toward Earth. The European Space Agency (ESA) is taking part in the NASA-led exercise, but a full European response is going to need a shift in space spending, which must be decided by ministers in November.

The scenario being run by global experts at a conference in the U.S. starting Monday is based on the fictional premise that an asteroid measuring between 100 meters and 300 meters was detected March 26, with a 1 in 100 chance of striking Earth in April 2027.

It's a precursor to a 2021 NASA mission dubbed the Double Asteroid Redirection Test (DART). By 2022, and more than 11 million kilometers from Earth, the mission’s spacecraft will impact a 160-meter asteroid orbiting a larger 780-meter asteroid.

The goal is to see how much that affects the asteroid's trajectory — crucial in any bid to deflect a space rock headed to Earth.

Around 20,000 asteroids with an orbit bringing them close to Earth have been detected so far, with around 150 discovered every month, ESA says.

To make very precise measurement of the asteroid’s movement, ESA is backing a project called Hera, after the Greek goddess of marriage; it would launch a spacecraft in 2023 to perform a crash-scene investigation, feeding vital data back on how the mission worked out.

“The Americans will do what they do best and blow things up,” said one European space industry official of the DART mission.

Europeans are better at haggling over budgets, which is why ministers from ESA (which includes EU but also non-EU countries) will hold a summit in Seville in November to determine how much public funding to allocate to Hera and who pays. The cost is estimated at €290 million, with ESA’s 22 countries being asked to cough up €140 million this year and the rest in 2022.

While satellite builder OHB, based in Bremen, Germany, has won a €4.5-million contract to carry out a study on the spacecraft needed for Hera, the bigger investment is still pending approval.

Germany, Belgium and Spain already have skin in the game, with their companies developing systems needed for Hera to work, said Ian Carnelli, who helps run Hera at ESA. Sweden, Romania, Portugal, the Czech Republic, Austria and France are also involved.

Italy is yet to secure a role, and a spokesperson for the U.K. government said it has not yet decided whether to contribute.

“No one wants to show their cards too soon,” said Carnelli.

Separately, the European Commission wants to set aside €500 million for so-called space situational awareness projects in the bloc’s next space budget running from 2021. But that’s also yet to be agreed by countries and much of the cash would be spent not on asteroids but on programs to clear up the millions of bits of debris floating in space.

“It’s very urgent to start these developments,” Jan Wörner, director general of ESA, which is based in Paris, told POLITICO recently. The agency is independent of the EU, but the memberships largely overlap and the EU is the largest contributor to ESA’s budget.

Avoiding extinction

The money would go toward a worthy cause — preventing humans from following dinosaurs into extinction because of an asteroid strike.

The chances of that happening aren’t high, but they're not zero. There is also the danger of small asteroids that could have less existential but still devastating consequences.

Around 20,000 asteroids with an orbit bringing them close to Earth have been detected so far, with around 150 discovered every month, ESA says.

In 2013, a 20-meter meteor burned up on impact over Chelyabinsk, Russia, leading to 1,500 reported injuries. Should a space rock larger than Chelyabinsk be spotted hurtling toward Paris with just a year of notice, would Europe be prepared?

“To be very blunt, one year is still too short,” Wörner said.

This week’s exercise will cover how to deflect an asteroid by adjusting its trajectory away from any projected collision with Earth. That’s not the approach favored by Hollywood scriptwriters — they generally call for blowing up space rocks with nuclear weapons — but it is likely more effective.

“'Armageddon,' you know, the movie with Bruce Willis [in which the heroes detonate a nuclear bomb inside an asteroid], that’s not the right method as it’s even more dangerous than doing nothing," said Wörner.

The best chance of avoiding disaster is by playing “billiards” in space, he said, and using the kinetic energy of a spacecraft impact to nudge the rock onto a different course.