From years of researching fireball reports, I can tell you they always seem to.<br />In fact they never do, that would be very bad.<br /><br />For example, the Tunkuska event (99th anniversery June 30th), which flattened hundreds of square miles (or km <img src="/images/icons/smile.gif" /> ) of trees, left nothing behind, as it exploded and vaporized at least 5 miles above the surface.<br /><br />Objects solid enough, large enough, and hitting the atmosphere slow enough for meteorites to survive intact to the ground lose their cosmic speed well above the suface. Once it explodes (from air pressure) many miles up, the non-glowing pieces continue to fall in what is known as dark flight under the influence of the earth's gravity.<br /><br />Even a small piece of rock travelling at cosmic speeds ( /> 11 km or 7 miles per second) is going to leave a big mark and ignite anything nearby.<br /><br />For example:<br /><br />"It was 150 feet across, weighed roughly 300,000 tons, and was traveling at a speed of 28,600 miles per hour (12 kilometers per second) according to the most recent research. The explosion created by its impact was equal to 2.5 megatons of TNT, or about 150 times the force of the atomic bomb that destroyed Hiroshima." <br /> <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>