How moddable are asteroids?

[optimusjamie]

So, I've had this idea for a mod.

KRAKEN HUNTING!

Basically, it would involve custom 'asteroids' that look and behave like the Kraken, and would mess with physics as you approached them (c.f. Magic Boulder). The idea is that there would also be custom contracts you could complete with them, for instance bringing a live Kraken back to Kerbin for absurd amounts of science and funds.

[robopilot99]

Asteroids are just large parts. They're just as modable as any other part.