No one knows why the ancient Mayans decided to end their long calendar on winter solstice, 2012. Or why folks who write fiction about ancient Babylonians and flying saucers decided there is a secret planet named Nibiru hidden behind the sun that will suddenly swerve out of orbit and crash into Earth. And, of course, the latest estimate for this occurrence is in 2012.

If all this sounds like an excuse for a Hollywood special-effects blowout, you are correctomundo. “;2012”; opens Friday, brought to you by the same folks who made “;Independence Day”; and “;The Day After Tomorrow,”; other world-enders. But the filmmakers have also created Web sites that pretend to be legitimately scientific, something that has real scientists somewhat annoyed.

David Morrison, NASA Astrobiology Institute's senior scientist, has been deluged by so many queries from concerned citizens that his “;Ask an Astrobiologist”; online question-and-answer site has a standing section on the issue.

“;It is not logical to ask for proof that the 2012 doomsday is a hoax,”; notes Morrison. “;Your questions should be to the doomsday advocates to prove that what they are saying is true, not to NASA to prove it is false. If someone claimed on the Internet that there were 50-foot-tall purple elephants walking through Cleveland, would anyone expect NASA to prove this wrong?”;

Peter Mouginis-Mark, director of the Hawaii Institute Geophysics and Planetology at the University of Hawaii, “;nearly died laughing”; when he first saw the “;2012”; trailer.

“;There's absolutely no scientific credibility behind it,”; said Mouginis-Mark. “;It's a lack of critical reasoning, I guess. Just because you see something that looks realistic on the screen doesn't mean that it is real.

“;One of the main functions of institutions such as the University of Hawaii is to educate the public so that they can be informed on what is plausible and what is fantasy. The earth, solar system and universe work along physical laws - with a better understanding of this relationship, the public can see for themselves movies such as '2012' are pure fabrications.”;

Mouginis-Mark added that there are more than enough potential catastrophes here on earth to keep us occupied, such as tsunamis, earthquakes and eruptions. “;There are numerous state and federal agencies in Hawaii that deal with these events on a regular basis. The Pacific Tsunami Warning Center, U.S. Geological Survey, NOAA, state Civil Defense and the University of Hawaii are just a few of the places to turn to for a reality check.”;

AT THE Institute for Astronomy, University of Hawaii, one of the organizations that scans the heavens for mystery objects, “;2012”; received a quick, general thumbs-down.

“;The general tone is bemusement rather than anger,”; said professor Gareth Wynn-Williams.

“;Scientists at the IFA actually prefer the movie 'Armageddon' to '2012,' because it deals with issues that we are working on at the institute - and because Liv Tyler is really cute,”; said Robin Uyeshiro.

Wynn-Williams also pointed out that the “;Heaven's Gate”; religious cult suicides in 1997 were triggered by astronomical mythology.

UH astronomer Dave Tholen's telescope images of the 1997 Hale-Bopp comet were doctored to provide fake “;evidence”; for the cult, and he said, “;If we have another Heaven's Gate in response to the rumored events, then the filmmakers should think twice about what they're doing.”;

“;Some of my students turned me on to these stories. I found that planet Nibiru was supposed to collide with Earth in 1999,”; said JD Armstrong. “;I must have missed the press release about its arrival. Now I see that its arrival has been rescheduled for 2012.

“;A planet that size should be easy to detect. A back-of-the-stamp calculation - in other words, not careful enough to be a back-of-the-envelope calculation - the planet wouldn't be farther than Saturn if it were to arrive in 2012. That should be easily visible.

“;Other theories seem to ... Oh! These are bad, aren't they? There is one consistency among all of these theories: 'Buy the book that I wrote about it.' I'll make a bet with them. I'll pay them a dollar on January 2012. If the world hasn't ended by January 2013, they can pay me back three dollars, my one dollar plus two more which I call stupidity tax.”;

Astronomer Jim Heasley is even more unequivocal: “;Well, BS comes to mind. Besides, 'rogue planet' makes it sound like they'd just go collide with Earth on a whim. This all goes back to the 'War of the Worlds' radio broadcast by Orson Welles. Fool me once, shame on you, fool me twice, shame on me.”;

The institute's Mike Lum thinks ancient civilizations' “;long”; calendars are interesting. “;I believe author Robert Bauval documented that the ancient Egyptians had a 26,000-year-long calendar, based on the precession of the equinoxes. I'm sure the Chinese had something similar. I assume that the Doomsday cultists just didn't want to wait until A.D. 23,000 to capitalize on the end of the world.”;

“;I thought that the world was supposed to end a decade ago,”; said Conrad Holmberg. “;Been there, done that!”;

Ken Chambers reminds us, “;There is scientific evidence the world wasn't destroyed at the end of the millennium.”;

And Colin Aspin simply quoted Douglas Adams, author of “;The Hitchhiker's Guide to the Galaxy”;: “;So long and thanks for all the fish.”;

Both Esther Hu and Kathleen Robertson cited recent articles by Anthony Aveni, a Russell Colgate professor of astronomy and anthropology at Colgate University.

This line caught Robertson's eye: “;A vast majority of those familiar with the Maya culture view their cycle-ending prophecies as lessons on how to restore balance to the world by promoting reciprocity with the gods, such as offering them debt payments in exchange for fertile crops.”;

Good idea, suggested Robertson. If the public really wants to ensure the “;continuation of the world and universe as they know and love it, they should make donations to the IFA via the UH Foundation.

“;Thus we'll be able to continue to monitor the galactic/Milky Way alignment, preventing our system from going off-track. And, if by chance the world is destroyed in 2012, we'll then make a good faith effort to return donations.”;