My guess is that the Earth and the collider would both be pulverized into millions of fragments, all different sizes.<br /><br />Some of the fragments would move into wild orbits, and eventually be captured by the Venus, Mars and Jupiter.<br /><br />The majority of the fragments would spread out more or less in Earth's orbit as a temporary asteroid belt. The Moon would then sweep up about 75% of these fragments over the next millions of years, and grow to become about 1.5x mass of the Earth. The other 0.5 masses would end up in Venus, Mars, Jupiter and the Sun.<br /><br />Maybe a few of the asteroids would become new moons to circle the object formerly called the Moon (which of course is no longer a moon). <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>