Ways the World Could End: NASA Edition

The beginning of the end?

Photo: solarseven/Shutterstock

Much has been made about the “impending” end of the world in 2012, but NASA assures us that this is much ado about nothing. While Hollywood and the Mayan calendar suggest that Dec. 21, 2012, will be the end of all things, NASA expects that the date will pass much like the Y2K scare — without so much as a whimper. It appears the agency is taking a “nothing to see here” approach. And yet, one day, the world will end. Most experts believe our sun will eventually supernova in 5 billion years or so, taking much of our part of the solar system with it. But there are other ways life on Earth — or in some cases, the Earth itself — might be destroyed. Here are seven ways that might happen.

Black hole: Gravity gone wild

NASA.

Black holes are thought to be the end of a massive star that has burned itself out. Gravity forces it to collapse upon itself, prohibiting all light from escaping from its center. If you were to fall into a black hole, gravity would wreck havoc with your body. As one mathematician surmises, you would be crushed in so many directions and stretched so thin in others that you would resemble a piece of spaghetti. But you’re safe if you don’t regularly travel in space, right? Except one thing – black holes move through space.

Thankfully, a black hole is not likely to bear down on Earth anytime soon. NASA assures us that there are no black holes close enough to the Earth to cause a problem, and that our sun is not big enough to create one should it collapse. (Though we’d have other things to worry about then.)

Supervolcano: Not your traditional eruption

Photo: John Pallister/United States Geological Survey/Wikimedia Commons [CC by 1.0]

Imagine a volcanic eruption in which layers of ash cover most of the continents. Magma 10,000 times the quantity from Mount St. Helens (pictured) is thrown hundreds of miles into the air. Think this is a science-fiction fantasy? Unfortunately, it’s not. Supervolcano eruptions are a part of Earth’s history. The largest volcanic eruption on Earth is believed to be the Mount Toba eruption in Sumatra, which happened some 74,000 years ago. It is believed that the force of this eruption came close to wiping out all life on Earth — including man.

But will it happen again? While there is no evidence that a super eruption is eminent, there are roughly a dozen supervolcanoes on Earth today. Even Yellowstone National Park is the site of a massive supervolcano. Yellowstone sits atop a subterranean chamber of molten rock and gasses, an area so large that it is considered one of the biggest supervolcanoes on Earth. Its caldera, or the equivalent to a crater top, is 1,500 square miles. Experts believe the last major eruption in Yellowstone was 640,000 years ago, throwing 8,000 times the amount of ash and lava of Mount St. Helens into the air.

Cosmic alignment: Shadow of a dark rift

A. Fujii/NASA.

NASA calls the cosmic alignment theory of 2012 one of the most “bizarre” doomsday scenarios out there. The idea is that on the winter solstice of this year, the sun, Earth and the center of our Milky Way galaxy will align and somehow destroy us all. NASA’s response to this theory borders on incredulity. In fact, such an alignment happens quite often, but it will not occur during the 2012 winter solstice. And while there is a black hole at the center of our galaxy, it is too far away to influence the Earth in any way.

Solar storm: Time to get out the sunblock

NASA/JPL-CalTech.

Our sun is a powerful star, regularly emitting coronal mass ejections (CMEs), or blasts of magnetic plasma. The strongest CMEs can have a profound effect on Earth, disrupting satellite communications, electronics and more by sending large doses of electromagnetic radiation and energetic particles our way. So will a CME ever be strong enough to destroy the Earth? NASA says no. Solar storms have a fairly regular cycle, peaking about every 11 years. In fact, the sun is gearing up to peak right now, with the next solar maximum expected to appear in 2013. But while they can cause significant problems, even the biggest solar flares are not powerful enough to destroy our planet.

Planetary smash-up: A high-speed collision in space

NASA/JPL-CalTech.

Another favorite from Hollywood’s file of doomsday scenarios: Could a planetary collision spell the end of Earth? NASA’s Spitzer Space Telescope has found evidence that this has happened in our galaxy. The young star HD 172555, just 100 light-years from Earth, may have been the center of a smash-up because NASA has found rubble, as well as signatures of vaporized and melted rock, around the star.

Has such a smash-up every happened in our solar system? Some experts believe that it has. In fact, our moon is thought to have formed when a fast-moving object slammed into the Earth some 30 million to 100 million years after the now 4.5 billion year old sun formed. The molten rock, vapor and debris that were flung off the Earth eventually coalesced into what is now our natural satellite.

Supernova: When the sky explodes

European Space Agency and Justyn R. Maund.

A supernova occurs in space when a supergiant star explodes, sending out almost incomprehensive amounts of energy. One expert measures this energy as “total output of the sun during its 10 billion year lifetime.” Further, experts believe that a supernova “within 100 light-years of the Earth would likely be a catastrophic event for our planet.” Has such an event ever happened in Earth’s history? Around 250 million years ago, a mysterious mass extinction took place on Earth. It is referred to as the Permian-Triassic extinction, or “The Great Dying.” Some experts hypothesize that a supernova blast may have caused the extinction.

Asteroid hit: What's good for the dinosaurs…?

Don Davis/NASA.

If this happened, the blast would sweep over the Earth and everything in its path would die. Carbon dioxide released from vaporized rocks would flood the atmosphere. The world’s forests would ignite. Millions of tons of dust would fly into the air, obscuring the sun and shutting down photosynthesis. The debris slowly falling back to Earth would poison anything that remained.

With such dramatic and dire consequences, it’s no wonder Earth-killing asteroids have been the subject of many Hollywood blockbusters. Unfortunately, it has also made a real-life appearance here on Earth. Scientists generally agree that an asteroid collision sparked the end of the dinosaurs. But will another asteroid do the same to humanity? Not as far as NASA can see, according to the space agency. NASA rigorously monitors all near-Earth objects. Yes, the asteroid Apophis is predicted to have a historically close meeting with the Earth in 2029, but most experts remain confident that the closest we will ever come to meeting an asteroid will be in the seats of a movie theater. At least in our lifetimes.