(meteorobs) Meteorite hits tractor

[RainerArlt]

Thanks, David, for forwarding this note.


> >From the Edmonton Sun
> 
> http://www.edmontonsun.com/News/Canada/2005/07/27/1149239-sun.html
> 
> [...]
> 
> "It's actually the process in which the planets formed where you get
> dust from space that agglomerate together. If it happens enough you have
> a planet, but in other cases you have a meteorite," said Galley,
> speaking from the federal government agency's office in Ottawa. 


This statement is misleading. Meteorites never form as such
in the early planetary system. All meteorites are fragments
of a larger body after some collision.

If you imagine dust coagulating in the early solar system,
it may coagulate to reach sizes of inches or meters, but
it is still dust - very fragile things which are not 'compatified'
to be a rock. Real rocks form in larger bodies with significant
gravity.

Nevertheless, meteorites can originate from very early bodies
which were yet not large enough to have a differentiated
structure like core, mantle, etc. But still they have never
formed besides planets and asteroids as the above statement
might suggest.

Best regards,
Rainer


--
Rainer Arlt  --  Astrophysikalisches Institut Potsdam -- www.aip.de
Visual Commission - International Meteor Organization -- www.imo.net
rarlt at aip.de --  phone: +49-331-7499-354  --  fax: +49-331-7499-526