Editing 243 Ida (section)

=== Age and origin ===
Dactyl may have originated at the same time as Ida,<ref name="GreenbergBottkeNolanGeissler1996p116">{{harvnb|Greenberg|Bottke|Nolan|Geissler|1996|p=116}}</ref> from the disruption of the Koronis parent body.<ref name="LeeVeverkaThomasHelfenstein1996p97" /> However, it may have formed more recently, perhaps as ejecta from a large impact on Ida.<ref name="PetitDurdaGreenbergHurford1997p182">{{harvnb|Petit|Durda|Greenberg|Hurford|1997|p=182}}</ref> It is extremely unlikely that it was captured by Ida.<ref name="Mason1994p108" /> Dactyl may have suffered a major impact around 100&nbsp;million years ago, which reduced its size.<ref name="GreenbergBottkeNolanGeissler1996p117" />