Alien Rubicon

An alien spacecraft lands off the coast of New York. It heads inland, destroying everything around it. The ship is a probe, sent EXPRESSLY to let us throw everything we've got at it.

If it reaches D.C., it'll destroy it and send a signal to the rest of their species to extinguish the rest of the planet. Now it's up to our scientists and military to figure out how to stop the unstoppable.