2003 EL61, News ... Options

[SigurRosFan]

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Mike Brown ... and his team discovered that five small Kuiper belt objects were travelling in similar orbits to 2003 EL61, the third-largest KBO ever found. The discovery hinted that the five pieces are fragments that split off after an ancient collision.
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- Icy chips off the old asteroid block

[Superstring]

Looking at the recent articles on the subject...is there any reason why they conclude the impact took place in ancient history? I ask because EL61 is a bright object covered in fresh crystalline ice (which can only last for 10 million years in that part of the solar system before turning amorphous). I had assumed this was due to the said impact that created its satellites and those other objects.

To me the presence of such fresh crystalline ice on most of its surface leaves two options: a)the impact that created the satellites and orbital family took place in the past 10 million years, or b)the impact took place long ago and triggered enough heat in the core for cryovolcanism which continues to this day.

I'm trying to rule out one or the other...anyone know if the ice on these smaller objects is crystalline? That would strongly suggest a recent impact. I know the brighter satellites has crystalline ice, but that doesn't necessarily rule out cryovolcanism, which could spray material onto its surface.