Tens of thousands of people lined up this weekend to see the world come to an end in the new movie "2012." The disaster movie was number one at the box- office.

Now, according to numerous sources, mainly on the Internet, in the actual year 2012, a planet called Nibiru will crash into the Earth, resulting in the extinction of the human race; or the Earth's magnetic poles will flip, causing the planet's rotation to reverse direction, resulting in the extinction of the human race; or the Earth will enter a dark rift in the Milky Way galaxy, resulting in the extinction of the human race.

David Morrison is an astrobiologist at NASA, and he's been answering hundreds of questions from people who are concerned about what may happen in the year 2012. He joins us from his office in California.

Welcome.

Mr. DAVID MORRISON (Astrobiologist, NASA): Hi, glad to be here.

RAZ: What is NASA doing to prevent the planet Nibiru from crashing into Earth and creating a disaster?

Mr. MORRISON: NASA has nothing to do with the Planet Nibiru because it doesn't exist. What NASA is going, or perhaps I should say what I am doing, is try to answer all these people who are really scared and see if we can't get some facts out to counteract the mythology on the Internet.

RAZ: What about magnetic poles flipping?

Mr. MORRISON: The Earth reverses its magnetic polarity once every 400,000, 500,000 years. There's no reason to think it will happen now, no reason to think it would cause a problem if it did, and more to the point, it's just fake to say that if the magnetic polarity changed, that would have anything to do with the rotation. They're uncoupled.

RAZ: Well, what about the Dark Rift?

Mr. MORRISON: The Dark Rift is just a place where there are dust clouds in the Milky Way. I can't imagine where anybody decided to be afraid of that. I've had so many astronomical things that people are afraid of. They're afraid of the star Betelgeuse, they're afraid of the galactic center, they're afraid of black holes, and it's just all vapor.

RAZ: So there is no cover-up. NASA is not covering this up.

Mr. MORRISON: NASA is not covering it up.

RAZ: Okay. Now, hundreds of people have been writing to you, asking you about 2012, and they are genuinely concerned and frightened about this.

Mr. MORRISON: Most people who write to me are simply asking: Will the world end? But the ones that really bother me, I don't know how to answer.

RAZ: Well, which ones bother you?

Mr. MORRISON: I've had three from young people saying they were contemplating committing suicide. I've had two from women contemplating killing their children and themselves. I had one last week from a person who said: I'm so scared. My only friend is my little dog. When should I put it to sleep so it won't suffer? And I don't know how to answer those questions.

RAZ: This is really serious. I mean, this is not just a joke. I mean, there are actually people who really believe this.

Mr. MORRISON: Yes, and it seems strange to many of us because we know that there's a lot of fakery on the Internet. But apparently, there are people who do believe it.

RAZ: Now, you are a serious astrobiologist. I mean, you have devoted your life to a very serious profession. Is it sort of, you know, annoying for you to have to answer these questions from people out there in the Internet, blogosphere world and so on?

Mr. MORRISON: It's unexpected. My questions on the Internet are about astrobiology, and I still get a few astrobiology questions about life in the universe, but they're overwhelmed by this concern about 2012, and it does upset me not because it takes away from my time but because all these people are being fooled by a big hoax.

RAZ: Now, three years from now, when December 21, 2012, comes and goes, let's say, without an incident, do you think that will be the end of all this doomsday stuff?

Mr. MORRISON: There's a long history of doomsdays. Remember Y2K?

RAZ: Yeah, of course.

Mr. MORRISON: Even the planet Nibiru was predicted to hit the Earth in May of 2003. As far as I know, it didn't, and someone just pushed reset, and now it's coming in 2012. So I don't think we'll ever be rid of apocalyptic stories about Planet X and the end of the world.

RAZ: That's David Morrison. He's an astrobiologist with NASA, and he joined me from the Ames Research Center in San Jose, California.

Dr. Morrison, thank you so much.

Mr. MORRISON: And enjoy 2013 when it comes.