Using high-fidelity simulations, scientists reported in a study published earlier this month that a stealthy asteroid as long as 330 feet could be annihilated by a one-megaton nuclear device, with 99.9 percent of its mass being blasted out of Earth’s way, if the asteroid is attacked at least two months before impact.
Ideally, asteroids targeting our blue marble would be identified decades ahead of time. If so, the hope is that an uncrewed spacecraft could slam into them with sufficient momentum to nudge them out of Earth’s way. This strategy, known as deflection, is getting its first test next year with NASA’s Double Asteroid Redirection Test (DART) space mission.
But an asteroid even several years away from Earth may not be suitable for deflection. At that stage, it may be too late to sufficiently alter its trajectory with a nudge. And if any deflection attempt proves overzealous, the asteroid may break up into smaller but still portly pieces that could hit Earth in multiple spots.
Using a nuclear blast to obliterate an interplanetary interloper “will always be the last resort,” said Patrick Michel, an asteroid expert at the Observatoire de la Côte d’Azur who was not involved in the study. But if we are short on time, it may be our only hope.
A team led by Patrick King, a physicist at the Johns Hopkins University Applied Physics Laboratory, ran 3-D simulations to see whether a nuke could provide planetary salvation. Like a wannabe Marco Inaros, a villain from the science fiction series “The Expanse” who schemed to bombard Earth from space, he hurled virtual 330-foot asteroids at our planet along five different orbital paths.