[meteorite-list] Small Asteroid 2010 AL30 Will Fly Past TheEarth

[geozay at aol.com]

>>The only objects I know of that are  moving
faster than the local escape velocity of the
solar system (and  hence must be from outside
our solar system) are a small percentage of
the  "meteoroids" detected by AMOR radar
systems. But they're so small they're  usually
referred to as "dust" or "micrometeoroids,"
although the largest  particles are at about
100 microns and might be called small
meteoroids by  some.<<

I'm not sure where all my original sources were from. Below  is what I 
wrote down in my notes about 12 years ago. 
>> The fastest  geocentric velocity a meteor can have while in solar orbit 
is 72 km/s (45 mps).  Visually a meteor at this speed appears to be a very 
fast streak.  From a  1948 - 1950 Canadian Radio survey, it has been learned 
that less than 1 percent  of all meteors were traveling faster than the 
established 72 km/s solar speed  limit. Of these that were traveling at apparent 
hyperbolic speeds, none were  traveling faster than 80 km/s. As the survey 
noted, this excessive solar speed  is within the realms of being measurement 
errors. But in recent years,  additional research has been done that 
indicates the Canadian survey was  relatively accurate. The Christchurch (New 
Zealand) meteor radar AMOR(Advanced  Meteor Orbit Radar) has also yielded about 
1% of meteoroids having an  atmospheric speed in excess of 100 km/s. In 
addition, the Ulysses space probe  dust detector has in 1994, discovered 
interstellar grains in the outer solar  system at about 5 AU, having hyperbolic 
trajectories. This mean it’s traveling  too fast to stay in orbit around the 
sun.<<

GeoZay