What's Killing You Now?

[Written for my school paper, The Stand]

How often is it that you think about the furthest reaches of outer space? It is probably not very often you think about Outer Mongolia, let alone the outer limits. Yet that is exactly where your doom will be coming from. There is more than enough out there to fry us a thousand times over. Our planet is only one of an incalculable number of others, caroming about the Universe in its own way, still vulnerable to the immeasurable number of potential threats.

Imagine a jet of raw energy erupting outwards, carrying more energy in it than the Sun will ever generate. Imagine something that - while lasting on the scale of seconds - could strip away the ozone layer, leaving only radiation in its wake. Despite only hitting one side of the Earth, it would flash-burn anything not in the shade and heat some parts of the atmosphere to the level of an oven. This is what can erupt from the heart of a dying star. This is the gamma-ray burst.

When a supernova collapses into a black hole, the fierce collision of forces in its core can result in two of these devastating cones shooting out of it. They can be so bright, it is possible to see them with your naked eye from halfway across the visible universe. Even from the far side of the galaxy, one of these bursts would be as bright as the Sun (though admittedly not in visible light). A supernova – the final death throes of a star – lets out about as much energy in its last few seconds as its star did over the course of its entire life. Gamma-ray bursts are around a thousand times brighter than that.

Now, if a burst were to actually hit Earth, it would not be pretty. Aside from the heat and radiation, a gamma-ray burst would turn ozone into nitrogen dioxide, which is essentially smog. Despite the fact that a burst would only hit one side of the planet, globally we’d probably lose about 30% of our ozone layer, though it would be closer to 50% in some spots. Keep in mind that the ozone holes that we have now are losses of less than 5% and you can see how bad this could be. Couple that with the fact that the lost ozone is now smog, able to block out sunlight, add the fact that nitrogen dioxide is water soluble and can become acid rain, and Earth is no longer recognizable.

It is a distinct possibility that one of these could hit Earth. It is a distinct possibility that it has happened before. One of the biggest extinction events in Earth’s history may have been caused by a gamma-ray burst. There was an unexplained ice age that happened around 443 million years ago. A gamma-ray burst that blocked out the Sun is a perfect explanation.

No, this is not a common occurrence for Earth. We are not blasted by gamma-ray bursts on a regular basis. It is also not something that should be immediately discounted. There’s one star, WR 104, that is on the brink of exploding into a tremendous supernova. Now, it may be eight thousand light years away (which translates to about eighty quadrillion kilometers), so the supernova itself is not going to hurt us, but that is near enough for a gamma-ray burst to hit us square on. Earth is positioned at almost exactly the right angle for this star to hit us square on. The most terrifying part of this is that since this star is eight thousand light years away, we won’t be able to see it go supernova or the burst coming until it has already hit us. It may have happened eight thousand years ago, but we won’t know until we’re dead.

So there’s an idea to toy with. We could be hurtling toward our doom right now. We really have only the slightest idea of what is out there. For all of our scientific knowledge, we only know about a fraction of what the Universe has to offer us. Who knows what could be just out of sight?

Sleep well.