<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I have a question that popped up while playing Civilization 4. (yes i love those games, sue me) =)Anyways, when a meteor or asteroid hits the earth does it affect the earth´s rotationspeed? I mean, if it´s coming from the right angle then the momentum should in fact contribute to the earth spinning faster and the days shortening. I want to thank everyone here for taking your time to answer all these great questions. I´ve had spent many hours just reading different posts and I am never disapointed with the answers. //Simon <br />Posted by _Simon_</DIV><br /><br />The quick answer is technically yes. However even with impacts as large as the dinosaur killer in Chixalub 65 million years ago, the change would be too small to notice. Certainly it couldn't have been measured back then
. Since we now keep very precise records, an impact that size might be measurable, if there was anyone left to mesure it. After all, the December 2004 earthquake in Sumatra made a tiny change to the earth's rotation rate ( something around a few nanoseconds a day, IIRC) due to the mass that was shifted. Not noticeable by humans, but instrumentally measureable.The last one large enough to have that large an effect was most likely the impact that created the moon from the blasted off material.</p><p>Any life on earth at that time was sterilized out of existance.</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>