Not since sci-fi authors figured out that, given human success rates at bioengineering, the likely result is an uninhabitable planet-wide nanotech/bacterial goo

Not since sci-fi authors figured out that, given human success rates at bioengineering, the likely result is an uninhabitable planet-wide nanotech/bacterial goo that eats anyone who lands. The ice comet solution has the added benefit of wiping out all of those pesky Martians, given the kinetic energies involved. Just ask any Pak Protector. (-: