Originally Posted by hhEb09'1

The SOmeone was moi, and thanks for following up. I suspect that the size estimates that you are using are based upon the size of the explosion of meteors--which means that if the object were bigger or more massive but the explosion was not created in the same fashion, the relationship between size and mass would not be so straightforward.

Not that I think it gives much credence to the original article, I just thought it had bearing on your question in the OP.

A cubic meter of rock weighs a couple ton, so a(n astronomical) object weighing a billion tons would be less than a kilometer in diameter, right? I haven't read the article you linked in the OP but is that the sort of size that he's talking about?