I’ve always had a morbid fascination with doomsday, particularly as it relates to astronomy. The end of the world via a space-related source would bring a whole new meaning to the word “helpless”. As a means of coping with this ever-present vulnerability (and movies like Armageddon and Deep Impact don’t ease many worries) I will scientifically investigate different doomsday scenarios to see what the likelihood of the various ways we could all fry like ants through a magnifying glass would actually be.
Cut to me in a bookstore, my equivalent to a candy shop for an eager child. I’m in the astronomy section when I stumble upon this book, written by Dr. Philip Plait, on astronomical (meaning of or pertaining to astronomy) apocalypse scenarios… Perfect.
Now cut to a montage of me reading DEATH FROM THE SKIES! (DFTS! from here forth) on my porch swing, on a lounge chair in my yard, a chaise in my living room, in the doctor’s office, “So Happy Together” in the background. Yes, perhaps I’m a closet nerd.
One of the first things I love about this book is how Plait writes for the seasoned astronomer as well as the newbie, or someone who picked it up because of the sadistic comic book-style cover art.
“The universe is trying to kill you. It’s nothing personal. It’s trying to kill me too,” starts Plait, setting a brutally, hilariously honest tone for the rest of the book before launching into popular doomsday scenario #1… Earth in the crosshairs of an astronomical (here meaning friggin’ huge) asteroid or comet.
Between the Lines
DFTS! begins all chapters with a short story, usually depicting a beautiful, clear day when disaster strikes, and this time onlookers notice that trees around them are casting not one but two distinct shadows. Then the sun appears to be streaking across the sky as it slowly descends upon the horizon, flooding the immediate perimeter with unimaginable light and heat. But don’t worry, the discomfort doesn’t last long.
Cosmic litter is strewn through space like you wouldn’t believe. Most of it is small enough to either burn up completely upon entering our atmosphere or land as a mere pebble on some remote mountain. There are, though, large objects out there that could potentially cause a doomsday situation in the tradition of popular movie Armageddon called NEO, or Near Earth Objects. The one that caused most of our Land Before Time friends to have such a bad day was the size of Mount Everest and landed in the Gulf off the Yucatán Peninsula in Mexico.
Now that you’re good and scared, let’s move on to the likelihood.
The most likely situation is only one 1 in 45,000, but still enough to investigate. Asteroid 99942, also called Apophis, is a NEO about 250 meters wide. While that may not sound as big as miles-wide space-bullies you see in movies, the impact of something that size would be roughly equivalent to 12-times the force of the strongest and largest nuclear explosion ever. So simply put, that’s just not good.
But Plait suggests that instead of trying to nuke an approaching threat (since most NEOs are made of iron, a good nuking would hardly tickle the now hotter asteroid as it laughs its way down to Earth) that we nuke around the threat. The shocks created by nearby explosions would significantly alter the NEO’s path of travel, and in space all you need is a little.
In the case of Apophis, it will pass so close to us on April 13, 2029, that it will actually be closer to Earth than many weather and communications satellites. We will have a 7-year window to change its path if necessary when it passes by again in 2036.
Plait details some other unpleasant deaths from above including super- and hypernovas, gamma-ray bursts (very interesting, and only recently understood), and the sunburn from hell as the result of full depletion of the o-zone before finally getting to black holes, the ultimate cosmic parasites.
The scenario plays out as such that astronomers around the world are noticing things aren’t where they should be; Venus is several arcminutes (an arcminute denotes 1/60th of a degree, used for some seriously small sky measurements) from where it’s supposed to be, and Mars appears to be drifting away rapidly before it finally disappears. From just seven million miles away, gravity on Earth becomes equal to the pull of the black hole as everyone appears to be weightless before we’re sucked into the sky.
In minutes, the Earth is vapor. In an hour, there is no sign we were ever here.
In order to understand the likelihood of death via black hole, Plait provides a sort of “life and times” of black holes.
Everyone has heard the expression that not even light can escape a black hole, and the expression is 100% true; a black hole’s escape gravity, or the gravity needed to escape the surface (if you can call it that), is equal to or greater than the speed of light.
Formed in the inferno of a supernova, a dying star’s gravity becomes too strong and it essentially collapses upon itself. The compression and accumulation of matter increases its strength, and gravity becomes even stronger. If the star was large to begin with, the push-pull idea becomes moot when the gravity is too strong for the star to explode back outward in the form of a supernova. Instead, the matter condenses even more to a zero point (think of it like the 0,0 point on the coordinate plane).
Voilà, you have a black hole.
Just to further blow your mind, black holes don’t just suck a bunch of what, but also the when which contains it, but that’s getting a little further into Einstein’s theory of relativity than I’m comfortable with at present.
Imagine that you and your friend are playing near a hypothetical black hole in your backyard. Your friend frolics a little too close and ends up getting sucked into the black hole (and you thought running with scissors was dangerous).
As the hole sucks up your friend, their cries for help would begin slowing down, much like a digital effect you’d see on television or by slowing down audio on a computer.
Visualizing this, my own understanding of space and time—here combined into a new field called “spacetime” with specialized research—have kind of reached their limits, so I’ll just let you chew on that much. Read the book if you want to have your mind blown completely open.
Thankfully, not even our sun is large enough to turn into a black hole, so although there are many of these monsters lurking in our own Milky Way galaxy, it can be reasonably assumed that we won’t be sucked into the sky anytime soon.
Having finished the book, I can honestly say that I can’t recall being so engaged by a book before. Not only that, but it’s informative; Plait gives the reader a lot of solid scientific information in a manner that is understandable to novice astronomers without being boring for those with an astronomy background, such as yours truly. As for other cosmic apocalypses, I particularly enjoyed reading about the death of the sun, a rather pertinent doomsday scenario that many have at least thought about or heard through the scientific grapevine.
I highly recommend reading this ominous yet hilariously entertaining science thriller to anyone as obsessed with astronomy and death as I frequently find myself to be. It’s quite a page-turner, if for nothing else than living vicariously through each chapter’s victims as they’re burned, squeezed, crushed, sucked up, spat out and blown to smithereens.