Come now, Howedar and Ossus . . . you can't possibly be serious. The planetoid blew itself to smithereens. You're picking
one piece out of the
numerous pieces of rubble that come out of the conflagration, claiming that it could
only be part of the crust, and claiming that when the planetoid explodes, the crust neatly comes apart like a jigsaw puzzle.
I mean, sure, this is a Voyager episode, but that doesn't mean you can throw out common sense as readily as the writers did.
Look at the shape of the planetoid. It is quite nicely round. Listen to what they said . . . 60km down equals within the upper mantle, below the crust. That means the planetoid has a differentiated core, mantle, and crust. Look at the planetoid's surface . . . areas of heavy cratering beside areas which are smooth. That is indicative of geologic activity. And last but not least, just look at the debris that was floating around after the clip above (
link). There's plenty of small stuff . . . how could this be if the only debris possible is large (relatively-speaking) pieces of crust?
If that were little more than a tiny asteroid of a size of just a handful of kilometers as you claim, the chances of it being spherical would be ridiculously small. Small bodies of a few kilometers in size don't have the self-gravity necessary to arrange themselves in such a shape. The 900+km asteroid Ceres
appears to, whereas the largest irregular object in the solar system, Saturn's moon Hyperion,
does not. It'll depend on density, of course, but this places a lower limit on the size of the planetoid of at least a few hundred kilometers in size.
It also couldn't be just a handful of kilometers in size because of the differentiation. To get differentiation, you need heat and gravity. The heat can occur due to gravitational stresses (i.e. from a larger body), or radioactivity (as is thought to have happened on Vesta, the irregularly-shaped 525km asteroid with a differentiated core), or just the heat of formation (EDIT: i.e. the heat which exists at the time of formation, i.e. that it is formed from molten bits). According to
this, you need a body at least 50-200 kilometers in size (that's the only general estimate I've found, but fits the other bodies I've looked at). This places another lower limit on the planetoid size, though the shape plus this would agree that it must be at least a few hundred kilometers in size.
The apparent geologic activity . . . the appearance of lunar-style maria on the surface . . . argues for an asteroid of at least Vesta size, though the idea of such a small body as Vesta being capable of having molten rock flows to the surface is considered surprising. Once again, that suggests a body no less than 500km in size.
The small size of even the largest impact craters suggests, assuming a system even remotely like ours, that the body is quite large, also.
Finally, there's the act of calling it a planetoid. That suggests it is smaller than what might commonly be called a planet, despite its general appearance as a moon-sized body. Our smallest planet is Pluto, though some have argued that it is too small and should be stricken from the ranks. Pluto's size is 2300 kilometers.
The general appearance, and the evidence, suggest a body on the order of 1,000-2,000 kilometers in size . . . not two, as the stalwart opponents of anything Trek argue.