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: ‘The line is getting fuzzier’: asteroids and comets may be more similar than we thinkWhile specimens may not be large, it turns out such dust particles are reforming scientists’ conception of asteroids and comets and are enough to reconstruct entire scenes in the history of the solar system. Asteroids and comets are primitive bodies left over from early in solar system formation, so the more we can know about their composition, the more we know about where they formed. Those asteroids that formed in the same neighbourhood as comets tend to be closer in composition to them.