Doomsayers who believe the world will end on Dec. 21, 2012, base their prediction on the end of the 5, 125-year-long cycle of the ancient Mayan calendar.
But what will the end of days look like?
There are a range of theories about how our planet will be destroyed.
Although scientists say there's nothing to worry about, we thought you should be aware of some of the ways Earth might meet its doom.
Believers in the Nibiru Cataclysm think Earth will collide with the rogue planet Nibiru, also called Planet X.
If a planet of this size was speeding toward us, "it would be the brightest thing in the sky, " NASA scientist David Morrison tells ABC News. While he's likely exaggerating, there's no way researchers would miss a planet in our solar system. I mean, heck, we can even see rogue planets 100 light years from Earth.
An "alignment of planets" will cause a total blackout
In this apocalyptic event, the planets align in a way that creates a total blackout on Earth.
"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, " writes NASA.
In this scenario an asteroid more massive than the one that wiped out the dinosaurs will smash into Earth.
Although a newly discovered 120-foot-wide asteroid that zipped between us and the moon earlier this week may have raised some hairs, astronomers are certain that no threatening space rocks will slam into us in 2012.
Solar flares have been known to muck up power grids when they are strong enough. But in this version of the Apocalypse, doomsayers believe a burst of energy from the sun will broil our planet.
While the sun IS nearing the peak of its 11-year cycle scientists say this cycle is "wimpier" than past ones.
A polar shift will result in Earth's destruction
A 180-rotation of the Earth on its axis, known as "Polar Shift Theory" because the North and South poles change places, will result in cataclysmic volcanic eruptions, earthquakes, tsunamis and other disasters.
2012年12月21日——世界末日？
世界末日论者们预言，地球将在2012年12月21日毁灭，其根据是古马雅日历。古马雅日历的周期是5125年，这一周期的尽头就是世界毁灭之日。
可是，世界末日那天到底是什么样子的？
关于地球毁灭的理论有很多种。
尽管科学家们告诉我们用不着担心，但 我们觉得，大家应该对地球毁灭可能的几种方式有所了解。
1. 地球与一颗流浪行星相撞
相信尼比鲁灾难理论的人认为，地球将与一颗叫尼比鲁的流浪行星相撞。这颗星也叫第十行星。美国航天航空局（NASA)的科学家大卫-莫里森在接受美国广播公司采访时说：“如果这么大的一个行星快速冲向我们，那它应该是天空中最亮的东西。” 也许他说得有些夸张，但是，太阳系里的行星，我们的研究人员不会看不见，我的意思是，我们从地球上可以看到远在100光年的流浪行星。
2。 众星连珠，导致地球笼罩在黑暗中
根据这一理论，所有的行星将重新排列，地球被完全遮敝。
“今后几十年里，还不会出现这种情况。但即使出现了这种情况， 它对我们地球产生的影响也会是微不足道的。
3. 一个巨大的小行星撞毁地球
地球将遭到一颗小行的撞击，这一颗比当年造成恐龙大灭绝的那颗小行星还要巨大。上周，科学家们在地球和月球之间发现了一颗直径120英尺小行星，运行速度非常快，引发了一些恐怖气氛。不过，天文学家们确信，2012年地球不会遭受来自太空的威胁。
4. 巨大的太阳光斑把地球烧成灰
太阳光斑足够强烈时，能够破坏地球上的电力网系统，这是众所周知了。但世界末日论者认为，太阳释放巨大能量时， 会把地球烧毁。现在，太阳已接近它11年周期之末，据科学家们说，本周期，太阳光斑的威力比以往周期要弱。
5. 地球毁于极地转换
“极地转换理论”认为，地球绕中心轴自转180度时，南极和北极互换了位置，这将引起火山爆发，地震，海啸等种种灾难。
今年地球一定不会毁灭。我们还需要更多证据吗？
地球曾有过10次遭毁灭的机会，但它至今岿然屹立。
