[meteorite-list] 2012 DA14 Family?

From: lebofsky at lpl.arizona.edu <lebofsky_at_meteoritecentral.com>
Date: Fri, 1 Mar 2013 12:48:51 -0700
Message-ID: <26296a7a5c19df353e9e9269fd9d8df7.squirrel_at_webmail.lpl.arizona.edu>

Hi Elton:

Apollos and Atens are technically groups of asteroids grouped by their
orbital parameters, only:

An Apollo asteroid has a mean distance from the Sun of more than 1.0 AU
and a perihelion (closest to the Sun) of less than 1.017 AU (Earth's
aphelion or farthest distance from the Sun), so is an Earth crosser.

An Aten asteroid has a mean distance from the Sun that is less than 1.0
AU. There is a subclass of Atens that are wholly within the orbit of the
Earth called the Apohele asteroids (or Atira asteroids, named for the
first CONFIRMED member of this group). I think that the aphelion has to be
less than 0.983, the perihelion of the Earth.

So, in neither case does the group imply anything about composition or
place of origin (probably the asteroid belt as it is unlikely that
anything big enough to be observed in space would have come from the Moon
or Mars!).

Larry


> Well, broadly, DA14 was an Apollo, perturbed into an Aten by its recent
> Earth encounter. Those categories are determined by orbit, not
> composition. These orbital categorizations are not sufficient to tie any
> asteroids to particular parents still in main belt orbits. Spectrally,
> DA14 is an L-type, which I don't think is sufficient information to make
> any association to an existing potential parent asteroid.
>
> Chris
>
> *******************************
> Chris L Peterson
> Cloudbait Observatory
> http://www.cloudbait.com
>
> On 3/1/2013 8:59 AM, MEM wrote:
>> Chris or Others?
>>
>> Has a family or possible parent asteroid been identified for 2012 DA14 ?
>> Or is it truly a lurker from parts unknown?
>>
>> Elton
>>
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Received on Fri 01 Mar 2013 02:48:51 PM PST