Having an "explosion" that is only barely large enough to shatter the planet and then let it coalesce more or less back together would be a special case. Within broad parameters, yes, but still a special case of an even broader set. If we can postulate an explosion in the first place, we can postulate one that sends most of the rock in escape trajectories, or makes it cease to exist altogether.
We have seen all sorts of such explosions already. The Species 8472 or Xindi weapons just made the planet go away; the two ways Praxis exploded in the two timelines both left half a world intact and the other half at least partially floating nearby. The DDM left behind dust and pebbles. While the death ray scenes never dealt with close celestial bodies one way or another (what happened to Luna in "Twilight", say?), none of these latter examples harmed other nearby (or indeed point-blank) worlds much...
Timo Saloniemi
We have seen all sorts of such explosions already. The Species 8472 or Xindi weapons just made the planet go away; the two ways Praxis exploded in the two timelines both left half a world intact and the other half at least partially floating nearby. The DDM left behind dust and pebbles. While the death ray scenes never dealt with close celestial bodies one way or another (what happened to Luna in "Twilight", say?), none of these latter examples harmed other nearby (or indeed point-blank) worlds much...
Timo Saloniemi