Thread: russian meteor
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Old February 20th 13, 10:43 PM posted to sci.astro.amateur
Dr J R Stockton[_193_]
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Default russian meteor

In sci.astro.amateur message
, Tue, 19 Feb 2013 08:39:33, Chris L Peterson

posted:

On Tue, 19 Feb 2013 03:09:28 -0800 (PST), wrote:

A satellite of a closely approaching asteroid could be moving in any
direction relative to the Earth. However, 2012 DA14 was several
hundred thousand kilometers away from the meteoroid, orders of
magnitude more than the typical distance of an asteroid moon.
Asteroid 2012 DA14 was very small, with a very low escape velocity.


A fragment of DA14 could be very far away from it (the existence of a
fragment is much more likely than of a satellite). But it would still
be in the same orbit as DA14, and therefore couldn't have produced the
Russian fireball.


DA14, and any gravitationally-unbound fragments, seem likely to have
made a number of reasonably close and therefore deflecting passes of
Earth and Moon in the past. In almost all of those, the deflections of
fragments will have been significantly different from that of DA14, and
the differences will have been much amplified on successive passes.

The Russian object could have been a fragment of almost anything,
including (but not especially) DA14. But it could not have been a
recent fragment of DA14.

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