I promised you Turn 5 this evening, so Turn 5 you will get!
Turn 5!
Damnit! They have pumpkins of mass destruction, start the extra large potato cannon production immediately.
4+2=6: The military's factories start mass-producing extra-large potato cannons. What the hell?
Have a satellite observe the comet. Ask scientists at NASA if it has anything to do with the aliens.
4-1=3: A satellite observes the comet. Woo. Perhaps you should watch the feed if you want more information. Also, the scientists are all too busy talking amongst themselves to answer your question.
Contact nations allied to us. Tell them not to be alarmed by the comet, we've got this, but that they may want to prepare militarily in case it is necessary. Do not mention aliens yet.
2-1=1: "HEY ENGLAND AND FRANCE AND ALL THOSE OTHER COUNTRIES THERE'S ALIENS COMING!"
You never tried chatting up women on the internet sir? Even one sent back in return could change the world!
Contact NASA. Ask if a comet was expected any time soon, and if not, get them to identify this one - is one missing from somewhere else? Or is this just a large meteor or lump of space junk?
3+2=5: The scientist that was previously tapping furiously on his phone looks up with a worried expression. "This... this shouldn't be here. Comets don't just appear out of nowhere like this. I'm not even convinced this is a comet. It doesn't look like anything we've ever observed. It's moving way too fast!"
Beam radio waves to the Comet, try and contact it!
2+1=3: You shoot some radio waves at the comet. Strangely, nothing bounces back.
Fire all missiles at the comet!
5+1=6: You order all of the country's missiles to be fired at the comet. For whatever reason, you are able to make this order, insteading of the President. Wait, where is the President? Oh well. The missiles are fired, including those in Samus's tank. As they're firing, you remember back to college, when you saw a movie about America accidentally firing missiles into space, and Russia responding with massive retaliation.
...wait. Doesn't Russia claim to have a mutually-assured destruction system?
Well shit.
The bright comet in the sky grows brighter and larger with each passing minute. One of the NASA scientists predicts that it will arrive in 1 hour.
But, the aliens aren't due for another 3 hours. What is going on? People start rioting in the streets out of fear and confusion. The thousands of missiles flying into outer space don't help much, nor does the mass production of extra-large potato cannons.
3 hours remain...