Impacts

[zarnic]

There have been several North American meteor impacts in the past: the Chesapeake Bay crater, Arizonas' impact crater, and even one about 13,000 years ago near the Great Lakes ... so what are the chances of such an event happening during the Perseid Meteor shower? Should we keep our heads down? <div class="Discussion_UserSignature"> <p><em>Wisdom doesn't automatically come with old age. Nothing does - except wrinkles.</em> A. Van Buren, 1978<br />* <em>An unbreakable toy is useful for breaking other toys.</em>  -- according to Van Roy</p> </div>

 

[MeteorWayne]

The Perseids would be no more likely that any other moment.<br />The Perseids are comet dust particles; Impacting objects are asteroid pieces, coming from the other direction (catching up to the earth from behind, unlike the Perseids, which hit us nearly head on), hence totally unrelated. <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>

 

[zarnic]

Thank you, my ignorance. <img src="/images/icons/crazy.gif" /> Now I won't have to buy a hard hat. <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><em>Wisdom doesn't automatically come with old age. Nothing does - except wrinkles.</em> A. Van Buren, 1978<br />* <em>An unbreakable toy is useful for breaking other toys.</em>  -- according to Van Roy</p> </div>

 

[MeteorWayne]

We learn by asking!<br /><br />I wanted to correct my previous post, I could have edited it, but felt the correction deserved it's own post.<br />The Perseids do not hit us nearly head on.<br />The inclination is 113.45 drgrees.<br /><br />What that means is that while Swift Tuttle and the Perseids do revolve around the sun the opposite way around the sun than the earth, the orbit is much closer to 90 degrees (above and below the plane of the solar system) than it is to hitting us head on.<br /><br />The pre-atmospheric velocity is 59 km/sec=37 miles/sec= 132,000 mph.<br /><br />Since the atmosphere where meteors glow is about 100 km thick, and the Perseids burn out above 60 km, they last at most a second or two.<br /><br />Even if there were a larger chunk buried in there, due to the very high speed, the object would never survive the trip through the atmosphere.<br /><br />In contrast, the kappa Cygnids, also active for the next week hit at only 25 km/sec=15.5 miles/sec=56,000 mph.<br /><br />So not only do they last longer, they have a better chance of reaching the ground. However since they too are from a comet, the pieces are VERY unlikely to be large or dense enough to survive. <br /><br />Stuff that hits the surface (impacts) is denser material from asteroids, hitting at slow speeds.<br /><br />There are a few times of the year when such objects are more likely, now is not one of them.<br /><br />After the Perseids, when I can sleep and do some research I'll revisit this issue for you, if you are interested.<br /><br />Wayne <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>

 

[3488]

I am very interested in this MeteorWayne.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>