I found a crashed UFO and then found the actual Alien, he was communicating via radio with his home planet, think they will come to try and rescue him/her/it however I killed it and looted. Did I start a Galactic War?

I found one also (probably the same one) near the Charles River, and the alien hiding in a cave. I killed him also because he shot at me first, got a nice pistol out of it. Would have been nice to see a non-confrontational situation when meeting the alien. But I agree, I think that one of the 4 DLC's to come out will center around aliens, maybe not the first one, but I think we will eventual see it.

I think that was more an eastern-egg, I don't think that this crashed UFO is a prove for a planed DLC

Aliens have been an Easter Egg in Fallout since the first game. There was also a group of aliens in New Vegas as a clear "wacky wasteland" trait. So I wouldn't assume an alien DLC is confirmed from another Easter Egg encounter in the game.

Crashed UFO and the hostile alien(s) encounter has been part of Fallout since the first one came out.

They want your salisbury steak.

I need to join the Minutemen, the Commonwealth must protect my Steak at all costs!

Standard Fallout Easter egg type encounter. I'm sure Bethesda learned their lesson with fhe atrocity that was Mothership Zeta and will not release any similar DLC content.

That's a pretty powerful Ham Radio he found then.

God, I hope not. I'd like them to expand on the content and to add some real stories, not another excursion into space.

But whatever it will be, you can bet everything you own, it's already well underway.

Only if you assume he was trying to contact help from space, they could already be on earth in a bunker somewhere you know.

The interesting thing about that crashed vessel is that it is NOT there to start out with. Not sure what triggers it to crash. I've cleared the cave prior to it being there and no alien. Have yet to see it spawn during my current playthrough.

When traveling around that area on foot, there will be an event where you will see and hear the ship flash across the sky, and most likely your companion (if you are traveling with one) will make some comment about it.

I must've missed that in my level 74 game. I had been through there many times and never noticed it, then one day "What the heck is this!?"

I missed it also on my first play-through, I did see it on my second though, and rushed right over and grabbed the blaster. Dunno why though, its a pretty mediocre pistol that's not worth the time to get it.

Both times it happened to me right after fast-travelling to the Cambridge Police station, which is not too far north from the crash site (around Level 20 I'd say). The first time it's scared the hell out of me. I was wondering what was going on, and Piper commented on the crash, saying we should probably investigate or something like that. I had to check online for the site location because I never saw the ship in the sky, just heard the noise.

Yeah, but I hear firefights and explosions off in the distance all the time! Was it somehow distinctive?

I'd kinda like to see it up close. I wonder what the triggers are to make it happen?

I doubt they'd redo dlc and I'd be pissed if they did.

There's a distinctive continous loud sound followed by a crash and explosion. Found a video of it:

https://www.youtube.com/watch?v=fZiIvwcVnMY

I love aliens. Wouldn't say this was a confirmation, by any means.

So level as I get close to finishing level 19 I should be lurking in that area along its path and preferably close enough to see it actually impact

The Borderlands Pre-Sequel game out last year has probably stolen this thunder- it would be a foolish business decision to put out a DLC with the same theme as a very successful competing game.