A METEOR that exploded over Russia in February was 20m in diameter and caused a blast equivalent to 540,000 tonnes of TNT, according to scientists studying the event.
The space rock blew apart 30km above the city of Chelyabinsk, inflicting severe burns on a number of observers below.
It was the largest object to hit the Earth since the Tunguska event of 1908, when an exploding comet or asteroid destroyed 2000sq km of Siberian forest.
Professor Qing-Zhu Yin, from the Department of Earth and Planetary Sciences at the University of California at Davis, US, said the meteor strike was a "wake-up call".
"If humanity does not want to go the way of the dinosaurs, we need to study an event like this in detail," he said.
The meteor, scientists believe, broke off a passing comet that was several kilometres long and even wider than that.
If an interplanetary body that size hit the Earth, they said, it would likely be a "world-ending" event, potentially killing everything on the planet.