NASA官網(wǎng)短片辟謠：12月21日并非世界末日

Dec. 21, 2012, won't be the end of the world as we know, however, it will be another winter solstice. Contrary to some of the common beliefs out there, the claims behind the end of the world quickly unravel when pinned down to the 2012 timeline.

Q: Are there any threats to the Earth in 2012?

A: The world will not end in 2012. Our planet has been getting along just fine for more than 4 billion years, and credible scientists worldwide know of no threat associated with 2012.

Q: What is the origin of the prediction that the world will end in 2012?

A: The story started with claims that Nibiru, a supposed planet discovered by the Sumerians, is headed toward Earth. This catastrophe was initially predicted for May 2003, but when nothing happened the doomsday date was moved forward to December 2012 and linked to the end of one of the cycles in the ancient Mayan calendar at the winter solstice in 2012 -- hence the predicted doomsday date of December 21, 2012.

Q: Does the Mayan calendar end in December 2012?

A: Just as the calendar you have on your kitchen wall does not cease to exist after December 31, the Mayan calendar does not cease to exist on December 21, 2012. This date is the end of the Mayan long-count period but then -- just as your calendar begins again on January 1 -- another long-count period begins for the Mayan calendar.

Q: Is NASA predicting a "total blackout" of Earth on Dec. 23 to Dec. 25?

A: Absolutely not. Neither NASA nor any other scientific organization is predicting such a blackout. The false reports on this issue claim that some sort of "alignment of the Universe" will cause a blackout. There are no planetary alignments in the next few decades and even if these alignments were to occur, their effects on the Earth would be negligible. One major alignment occurred in 1962, for example, and two others happened during 1982 and 2000. Each December the Earth and sun align with the approximate center of the Milky Way Galaxy but that is an annual event of no consequence.

Q: Is the Earth in danger of being hit by a meteor in 2012?

A: The Earth has always been subject to impacts by comets and asteroids, although big hits are very rare. The last big impact was 65 million years ago, and that led to the extinction of the dinosaurs. Today NASA astronomers are carrying out a survey called the Spaceguard Survey to find any large near-Earth asteroids long before they hit. We have already determined that there are no threatening asteroids as large as the one that killed the dinosaurs.