I woke up thinking about it so I just spent an hour calculating the impact of a Gundam colony drop on the Earth's surface.
Thread:
Assumptions: 1) Freefall from Lagrange point that shares a lunar orbital distance. 2) Density of a colony is very, low. I calculated it as 1/100th the density of a Boeing 737-100's dry weight. (This works out to slightly less dense than expanded polystyrene, aka Styrofoam)
The numbers:
Final estimate of the mass comes in at 1.403x10^12 kg
That's, uhh... 1,403,000,000,000,000 kg or, for the Americans, roughly 1.6 BILLION TONS.