Republish this content You must give appropriate credit. We ask you to do this by: 1) Using the original journalist's byline 2) Linking back to our original story See our full republication guidelines here HTML for this article, including the attribution and page view counter, is below: h2 Q&A: How we’re gearing up to deflect asteroids that might cause Earth considerable damage /h2 br p Humans are also considering mining asteroids for metals, but one of the crucial reasons scientists study this ancient space rubble is planetary defence, given the potential for space debris to cause Earth harm. /p