A house-sized asteroid grazed past Earth on Thursday, passing harmlessly inside the Moon's orbit, as predicted, to give experts a rare opportunity to rehearse for a real strike threat in future.
Dubbed 2012 TC4, the object's passing allowed scientists to practice spotting incoming objects, predicting their size and trajectory, and tracking their passage with a global network of telescopes and radars.
“We pretended that this was a critical object and exercised our communication,” said Detlef Koschny of the European Space Agency's Near-Earth Object programme.
The trial run was “a big success,” he said, despite some instruments not working as planned.
A radar system in Puerto Rico, for example, was out of service due to damage from the recent hurricane there.
“This is exactly why we do this exercise, to not be surprised by these things,” Koschny told AFP.