Re Asteroid 2004 FU162<br /><br />Well a 6 meter asteroid is going to be hard to spot.<br />Still it's an interesting one, though only fireball class, not impact class.<br /><br />The orbit which shows a possibily of intersecting earth is based on only 4 observations on one day (actually 44 minutes!) so has huge errors, both in orbit, and velocity along the orbit (which are almost always larger)<br /><br />In fact the impact possibility is based strcictly on the MOID which is VERY small. In fact if you look at the orbit diagram applet, you will note that on Mar 31st of this year it is expected to be on the opposite side of the sun, and in fact will be invisible all year, if the measured speed is correct.<br /><br />The reason for the March 31st date is that it is the date when the earth comes closest to the asteroid's expected orbit. That means that until the asteroid is recovered, and therefore accurate speed can be determined, there will be a risk on March 31st of every year when the earth crosses the asteroid orbit.<br /><br />This object is so small, I would not be surprised IF it is finally spotted again, it would not be recognized as being the same asteroid right away, so might have a new number assigned to it. <br />However, good reason to keep an eye on the sky on the 31st <img src="/images/icons/smile.gif" /><br /><br />NEODys MOID is 0.00021 AU, or less than 32,000 km, JPL is .00007 AU or just over 10,000 km.<br />Because of the huge error ellipses, it's not even listed on the JPL close impact page, and NEODys does not list a close approach again until 2010,2013,2016,2019, 2022 (detecting a pattern here?). NEODyS lists the minimum close approach as zero for all those approaches.<br /><br />If you run the JPL orbital applet, you can see why, since if the speed is accurate along the orbit, despite the close MOID, the object only comes close to earth every 3 years. It makes 4 orbits, and the earth makes 3 in the same time, so that's when they come closest.<br /><br />I'll have to <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>
Basic Error: The accelerating Universe conclusion - reason
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