Happy 2013 (and 5 ways the Cosmos Could Really Kill Us)

Happy New Year's Day! 2013, the year many never expected to see, has arrived and so goes the whole 2012 Doomsday nonsense as because by now, as even the most ardent of believers can't deny, the world is not going to end in 2012 thanks to the flipping of the calendar, which means that we can breathe a whole lot easier, or does it?

The fact is we live in a dangerous universe that can destroy Earth in several ways. The good news: while there are a lot of ways that could, in theory, wipe out all life on Earth, these events are extremely rare and the chance of any one of them taking place in any given year is very, very small. That said, why not look at ways the cosmos many of us love to study and admire could do us in, anyway?


1. Dying Sun.
Like people, stars are born, mature into 'adulthood,' grow old, and die. The glowing clouds of nebular gasses that so enchant modern astronomers and astrophotographers are, in reality, stellar corpses, the remains of stars that have died after using up all of the fuel that kept them shining brightly for millions, perhaps billions of years, chilling reminders that nothing lasts forever. When a star is in the prime of life, it fuses hydrogen atoms into helium, releasing untold amounts of energy the equivalent of billions of thermonuclear explosions a second. Why does the star then not blow itself up? Gravity. While the force of the nuclear fusion seeks to push out a star and make it expand, the star's own gigantic mass produces a gravitational force that keeps the star in a state of equilibrium between these two, competing forces.

A star begins to die when it uses up all of its hydrogen fuel. The nuclear fusion stopped but gravity still going strong, the star contracts into itself thanks to gravity. However, as the star contracts, it heats up to the point where it can start fusing helium nuclei together, releasing far more energy than it would with hydrogen fusion. Result: The extreme amount of energy released by the helium fusion somewhat overcomes the force of gravity, thus causing the star to swell to several times its original size, its outer atmosphere cooling as it expands. So, despite its growth in size to the red giant phase, the star is living on borrowed time as it will continue the cycle of burning an element, contracting, fusing an even heavier element, expanding, and so-on until iron is the next material in line for fusion. Unfortunately, iron fusion cannot occur because it takes more energy to fuse the nuclei than the fusion itself will generate. Result: Fusion stops and the star dies. In the case of the Sun, the Earth will have long since been engulfed by the swollen star itself by the time fusion stops. However, the Sun need not engulf Earth to destroy its life-giving potential. As the Sun expands, all the water will evaporate, the planet will heat up, and eventually the atmosphere will dissipate, leaving a hot, irradiated world inhospitable to life.

2. Impact by a large body.
The ancients thought that the heavens were perfect and unchanging. Now, we know that nothing could be further from the truth as we live in

a cosmic shooting gallery. Want evidence for this? Just look at the crater-marked Moon, which bears witness to 4 billion years of impact events. On Earth, thanks to weathering and other geologic processes, the impact scars are often smoothed away over time, are obscured by plant growth, or are just so big that they are hard to recognize except from space. However, one thing is clear: Earth has been hit by asteroids and comets in the past and will be hit again in the future. Just over a century ago, Earth had a close call when something exploded over the Tunguska region of Siberia, leveling hundreds of square miles of forests. Needless to say, if such an impact had taken place over a populated area, the damage and death toll would have been catastrophic, and that was just a tiny body on the true scale of rogue space junk. If something bigger were to hit, we humans could easily go the way of the dinosaurs, our technology being unable to save us.

3. Monster solar flares.
Note:

This is unlikely going by what we know about the Sun, namely that it seems to be a very stable star, but it is not entirely out of the realm of possibility. On other stars, truly monstrous flares powerful enough to fry Earth have been observed. The good news is that these events occur on other types of stars and on stars with binary partners. The implication: the star being late in life as an unstable red giant increases the tendency for life-destroying flares, as does gravitational interaction with a companion star. Obviously, the Sun fits neither category. Still, though, it is an interesting possibility. So, if the Sun were suddenly to explode in killer activity, what would happen? Short answer: A monster blast of highly-charged particles from the Sun could, in theory, strip away the Earth's protective magnetic field and thus allow the Earth to be blasted by deadly doses of radiation.

4. Rogue black hole.
Nearly a century ago, when developing his theory of relativity, Albert Einstein discovered that his equations allowed for the possibility that the universe is expanding from a giant explosion and the idea that there could be stars with no area at all, so-called

'black holes,' named for the fact that their gravity would be so strong that not even light could escape. Even for a man as genius as Einstein, these ideas were just too much to believe as Einstein added his infamous, erroneous 'cosmological constant' to steady the universe and, as for black holes, they were just too weird for scientists to believe on theory alone.
In the 1960s, though, evidence for black holes started to come to light. In the constellation Cygnus, there was observed an empty point in space that was radiating X-rays without cause. Working through various theories, scientists were baffled. Finally, in desperation, the old, moldering idea of the black hole was resurrected and, guess what, Einstein's almost too weird to believe idea fit the observations perfectly. In the years since black holes have been detected (remember, we can't see the,) all over the place, including true monsters at the centers of galaxies.

So, what would happen if one rogue black hole were to come and pay our solar system a visit?
Short answer: a lot of bad things.To learn more, read on. Because a black hole is all about gravity, some very weird things would happen in regards to the way the world operates. As the black hole neared the solar system, the orbits of the outer planets would go awry thanks to the massive, infinitely dense boy moving among them. In fact, the outer planets could be sucked in to the black hole, thrown out of the solar system, or, as best case scenario, have their orbits drastically altered. As the black hole got closer, Earth's orbit would become erratic because of the massive gravitational tug. Looking into the sky, the stars would appear to shift in position because the light coming from them would be twisted by the black hole's gravity. As for Earth's doom, one of three things could happen: it could get sucked in, thrown out of the solar system, or wind up in a drastically altered orbit. In a close call, Earth would find itself thrown out into the blackness of space, away from the Sun, and itself an ice world in short order. In a lesser pass, Earth would fine itself on a drastically altered orbit that could take it to the outer reaches of the solar system, in far too close to the Sun, or both. Now, for a direct hit. A hard to believe as it may seem, when the black hole got close enough, everything on Earth ranging from people to oceans would be pulled off the surface of the planet and into the black hole, wherein it would be 'spaghettified' out of existence.

5. Gamma Ray Burst.
For reasons scientists do not fully understand, every now and then, there are massive explosions of gamma rays called gamma ray bursts that come from distant space. The current theories state that such bursts come from especially powerful supernova, though that idea may have to be modified in the future as our knowledge and instruments become even better. Either way, a gamma ray burst in our neck of the galaxy, namely within 6,000 light years (give or take depending on the source) of Earth, could be very, very bad news for humanity as, even at that vast distance, the radiation burst could be powerful enough to strip away much of Earth's protective atmosphere and/or disrupt our magnetic field, thus leaving Earth unprotected from solar radiation which, unfiltered by the atmosphere/magnetic field, will prove deadly with time, leaving an uninhabited, ghost planet in its wake. Throughout Earth's history, there have been mysterious, mass extinctions that seem unexplainable by science. One of these vents took place about 440 million years ago, when over 50% of life on Earth was wiped out for reasons unknown. However, one interesting fact is this: the surviving species all descended from deep-water organisms, this suggesting that something left the deep oceans untouched while killing everything on land. A prime suspect here: a gamma ray burst.


So, as the new year arrives, if you were scared about 2012, rest assured that the world can't end in this year of doom as 2012 is now in the past. Now, as stated at the start of this article, keep in mind that the chances of any of the 5 real life cosmic Doomsday scenarios actually taking place is almost infinitely small but, on the other hand, these things can happen. My advice heading into 2013? Take time to enjoy the stars (or whatever it is you like to do) because life is anything but certain.

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