What's the difference between a comet, asteroid, meteor, meteoroid and…

With all the recent buzz over asteroid AD14, the meteor over Chelyabinsk, the fragments of meteorite recovered in Russia's Ural mountains, and yesterday's news that the fireball originated from our solar system's asteroid belt, one can't help but wonder: what's the difference between all these -oids, -ors and -ites?… » 2/27/13 12:40pm 2/27/13 12:40pm

The World needs an International Asteroid Warning System

Here's a hypothetical scenario: a mountainous asteroid is hurtling toward Earth. The world's governments are scrambling to notify their citizens. What country (countries?) should take charge? Where should people turn for instructions on how best to prepare for the impending impact? How will notifications and updates… » 6/07/12 11:31am 6/07/12 11:31am