Were the Apollo 11 astronauts prepared to defend themselves in the extremely remote chance that they encountered a hostile life form on the Moon?
Are you serious? 
You’re joking right? I’m pretty sure that NO US spaceflights have included any kinds of weapons whatsover. There would be no use for them, would add unnecessary weight, and would be very dangerous to all aboard.
Steve
No, they did not carry weapons.
We knew an awful lot about the moon before we ever landed on it. In particular we knew that there was no noticeable life there.
In the off-chance that there were evil anaerobic temperature-resistant microbes living there, the astronauts were always quarantined for a while after returning.
If there had been some aliens on the Moon, they either would have been aliens from another solar system or some form of rock monsters. If they were aliens from another solar system I would have to think their level of technology would make a .38 a useless weapon. And if they were rock monsters, well, the bullets would have just bounced off. So no, they didn’t carry frickin’ GUNS.
IIRC, there is a display in the Smithsonian of a survival kit that was carried by one of the early astronauts. Apparently, the thinking was that a capsule might splash down far from the intended target area and the astronauts could end up marooned in a life raft or on an island somewhere. I don’t recall the contents of the kit but it’s conceivable that it may have contained a knife for hunting or defense against wildlife or even hostile locals. IIRC the kit was from one of the pre-Apollo programs but it’s possible that the practice was continued in the Apollo program. But, if they did have knives (or any other weapons) they weren’t to be used on the moon and they wouldn’t have actually been taken to it’s surface.
How about regular guns? 
I know it sounds silly, but think about it for a moment. This was the first time humans were to set foot on another world. Sure, it was a world that had been studied enough, albeit remotely, to ensure that the astronauts wouldn’t encounter little green men. But don’t you think that during some NASA brainstorming session that the possiblilty that SOMETHING might be up there came up? Hey, it’s an alien world, maybe there WAS some silicone-based “rock monster” life up there. Or, if we managed to get a rocket up there, who’s to say there wasn’t some other visitors that got there first? 16th- and 17th- century explorers here on Earth came across creatures they never dreamed about. We’re still finding some today (like the giant worms surrounding thermal vents deep below the ocean’s surface).
I guess, due to weight and space considerations, astronauts can’t be prepared for such an unlikely contingency as an angry alien big enough to actually harm them. And what would one bring anyway? As RickJay points out, a gun would be useless. How about a set of brass knuckles big enough to fit over an astronauts glove? 
I think the only gun ever launched to and tested in space was the 23mm cannon on the Almaz space station. That’s for defending the station against Americans, not space aliens.
As for the Moon, we’ve been observing it for centuries and never found any sign of water, let alone life. (Until recently, anyway - there is now some inconclusive evidence suggesting presense of water ice, IIRC.) I don’t think the Apollo peoople would have considered the possibility.
Knives, razors, and shark repellant. As per the Smithsonian exhibit.
Believe it or not, I do remember reading a few times that the Soviets carried sawed off shotguns with them during their early space missions. This was not to protect themselves from any alien lifeforms, but instead it was to defend themselves against wolves and other wild animals here on earth after landing. The reason for this was that there were a few times when during re-entry, the landing capsule they were in would stray far off its intended course. This forced them to land in areas far off into the wilderness and caused their rescue parties several hours to get to them. While these cosmanauts waited, there was a very high and present danger that they could be attacked by wild animals, mainly wolves and bears…So…to prevent this, they started launching space vehicles that were equipped with both sawed off shotguns and other means of self defense…
I doubt if they were evef forced to use them though.
Maybe a little off topic, but when Jodie Foster is getting ready to blast off into space in ‘Contact,’ a mission director gives her a vial of cyanide “Just in case,” and says that NASA has been providing astronauts with these since the beginning of the space program.
Anyone know if there is any truth to this?
None whatsoever. Astronauts have never carried suicide pills.
This site shows the first South African cosmonaut during his survival training with the Soyuz shotgun. Note that there is always at least one Soyuz craft docked to the ISS.
http://www.firstafricaninspace.com/home/gallery/bolshoi/91.shtml
http://www.firstafricaninspace.com/home/gallery/coldsurv/1.shtml
The rest of the site is pretty interesting as well.
Even if there WERE alien life encountered by the astranauts, do you really want such a first contact to involve guns?
there was an earth based laser that could be used to protect the moon walkers
I add my corroboration of the stuff about Cosmonauts above. They do (or did) carry sawed-off shotguns in the capsule for the sole purpose of fending of wild animals after they landed (usually in a remote region of Siberia, where bears and wolves are more common than the average unarmed person would like them to be.)
None of the Apollo Astronauts carried weapons. As they landed in the ocean, I would think maybe a harpoon might have come in handy, but that wasn’t considered necessary, I guess.
There WAS? In 1969?
So while Buzz Aldrin is grappling with a moon monster, he calls in his coordinates to Mission Control in Houston, and they fire a laser across the void like an interplanetary gunslinger and pick off the alien punk? Nice shootin’, Tex! 
Upon further thought, I’m guessing that the astronaut’s defense plan (if any existed) involved running back to the lunar module and blasting off for home.
Yes. 1960’s style “Death Rays”.
There’s always one, isn’t there