Astronomers and engineers have failed to save New York from a fiery destruction - good thing it was just a simulation.

Many of the world's top brains gathered in the US this week for the 2019 IAA Planetary Defence Conference, part of which was to discuss how to handle an incoming asteroid, Armageddon-style.

Around 200 astronomers, engineers and emergency response specialists took part in an exercise to see how they'd react to an existential threat to the Earth.

According to the simulation, the fictional asteroid initially had a 1 percent chance of striking Denver, Colorado, in the year 2027. Further measurements boosted that probability to 100 percent, so the world powers decided to try and knock it off course.

They succeeded, to a degree - impactors smashed into the rock in 2024, but an 80m-wide piece of it broke off, headed straight for New York.

Much like what might happen in real-life, a plan to nuke it out of existence failed due to political disagreements, and on day four of the conference - 2027 in the scenario - it was confirmed the asteroid would strike New York's Central Park.