Which D&D die looks like this asteroid imaged by NASA?
The asteroid itself is too irregular to map well to any particular D&amp;D die.  I don't believe the author had any particular die in mind, which is why they use the term "the dice" instead of calling out a particular type die.

That said... it looks a lot like some D7's:



The D7 is not one of the standard D&amp;D dice, but I think is a much better match.  This variation of a D7 is not even a fair die, though neither is that asteroid by the looks of it.  All of the D&amp;D dice are fair dice; in fact, all but the D10 are Platonic Solids, hence none of them being a good match for the irregularities of the asteroid.