Some people are more than merely fascinated by the concept of the end of the world; they seem almost attracted by it. Maybe it’s simply that the endless stream of existential threats, from North Korea’s nuclear weapons to the evils of processed sugar, is exhausting. Americans and Brits are both action-oriented; let’s get it over with! For some, the appeal of a final cataclysm is no doubt linked to personal problems like depression or a bad FICO score. Others may be drawn to the biblical concept of the apocalypse, with its promise of a cleansing followed by a rebirth or resurrection. Whatever the source is, people’s absorption with Armageddon is widespread and never-ending.
The author is a longtime host and on-air commentator for Slooh, the online community observatory. Visitors to the site can join one of Slooh’s frequent real-time programs that use giant telescopes to stream true-color images of lunar eclipses, planet oppositions, and, most popular of all, close approaches of newly discovered near-Earth asteroids (NEAs).
Such NEAs zoom past our planet a few times a year. They’re typically discovered just a few days before they come closer to the Earth than any planet and sometimes even within the orbit of the moon. On February 15, 2013, we at Slooh announced that we would offer real-time telescope observations of an asteroid predicted to pass unusually close later that day. Then, that very morning, by sheer coincidence, a different asteroid approached from the opposite direction, the northeast, emerging from the glare of the sun. This one did not pass by us.
Residents of Chelyabinsk, Siberia, a region long kept hush-hush because it was involved with the Soviet and then the Russian nuclear-weapons programs, were startled by a brilliant “second sun” that streaked across the early-morning heavens. It left a smoke trail in the cloudless sky and exploded in a terrifying fireball eighteen and a half miles above the town.
No one would have been hurt had it not been for normal human curiosity; it drove thousands to peer out their windows at the lingering trail of white dust, and when the shock wave hit two minutes later, it violently blew out the glass windows, sending over a thousand bleeding people to the town’s hospital. Later calculations showed that the culprit was a sixty-foot-wide meteor that streaked toward the Earth at a speed of twelve miles per second. It broke apart eighteen and a half miles above the ground with the violence of a 440-kiloton nuclear weapon (the power of about thirty Hiroshima bombs). It then rained valuable fragments of itself onto the snowy countryside, fragments that were quickly hunted down and collected. A few of these can still be purchased online.
This celestial interloper promptly conjured images of its dinosaur-ending cousin that smashed into the planet sixty-six million years ago, and it made everyone vividly aware that it could happen again, this time wiping out every human instead of every raptor. The Chelyabinsk meteor wounded more people than any other space object ever had, although this was not difficult, since the previous record of meteoric injury involved only one person.
That earlier event happened in the United States in 1954 and was famous enough to make the cover of Life magazine. To merely state that its victim, Ann Hodges, was the only person in history to be hit by a meteorite is to give short shrift to a very unusual story.
On November 30, 1954, the Sylacauga, Alabama, woman, not feeling well, fell asleep on the living-room sofa in her rented white house across the street from the Comet drive-in theater (whose neon logo depicted a zooming meteor-like object, proving once again that irony is everywhere). Hodges was snapped out of a dream when the grapefruit-size stone crashed through the living-room ceiling. Before she could begin to react, it bounced off a wooden console radio, struck her left thigh, and bruised her left hand. The incident quickly drew crowds of journalists and put the thirty-four-year-old woman in the history books, along with area physician Moody Jacobs, who became the only doctor ever to treat someone injured by an object from outer space.
But Ann Hodges did not gain any financial benefit from this historic event, unlike Michelle Knapp of Peekskill, New York, who in 1992 was paid $66,000 by a collector for a twelve-pound meteorite that smashed into her Chevy Malibu in front of her rented house. In Ann Hodges’s incident, and to her incredulity, police officers and government officials took away the meteorite without her permission.
Ann and her husband hired a lawyer who eventually secured the meteorite’s return, but their hopes of making a fortune from the stone quickly faded when the landlady, Birdie Guy, claimed the meteorite was rightfully hers and fought for custody of it in court. The Hodgeses finally settled the case by giving their landlady five hundred dollars for the space rock, but by then the headlines were long over and the invader was no longer a hot or valuable item. The couple eventually turned it over to the Alabama Museum of Natural History at the University of Alabama in Tuscaloosa, where it remains on display.
Ann Hodges’s bruise was the only authenticated human injury from a hurtling space object for the next fifty-nine years, until Chelyabinsk’s flurry of cuts from window glass.
It was all more than enough to keep alive the peril-from-space motif—the fear of a giant Earth-smiting stone. In 1996, Discover magazine inflamed that concern with an article supposedly proving that one is six times more likely to die from a meteor impact than from a commercial plane crash. That seemingly implausible figure actually makes sense, since air travel is extraordinarily safe, while a biosphere-destroying giant-meteor impact, though vanishingly unlikely in any given year, could kill half of the Earth’s humans if it ever happened.
Which brings us back to those periodic Slooh programs that telescopically peer at NEAs as they whiz through Earth’s neighborhood. Public comments, always welcome during the shows, feature a repetitive theme: I don’t trust our government to tell us the truth if a giant asteroid was actually on a collision course with Earth. But I do trust you guys, so that’s why I come to this website.
While our company certainly welcomes visitors, it’s odd that so many think the U.S. government would keep an impending cataclysm a secret. A potentially catastrophic celestial collision certainly would not be kept hush-hush, for a couple of reasons. First, I count several professional astronomers among my friends, and I know them all to be blabbermouths. If any of them discovered a new asteroid, charted its predicted orbit, and found that it was going to intersect Earth’s path, the fact would be immediately blabbed to colleagues, family, friends, the media, and maybe even strangers on the street. And second, the federal government does not have any sort of mechanism or protocol in place for keeping celestial discoveries a secret. There isn’t even an existing national censorship mechanism for media stories. The author has been a contributing editor to three separate high-circulation national magazines for thirty years. Even when one of them (Discover) ran an article detailing the optical-resolution capabilities of the KH-11 spy satellite, no government representative asked the magazine to keep such stories out of print. It just doesn’t happen.
People probably get their ideas about government secrecy from sci-fi films in which some military bigwig is informed about an impending earthly collision and invariably tells his men to “keep it a secret or the public will panic.”
Of course, in the movie, the secret does get out and the public does panic. This pandemonium always takes the form of people running helter-skelter through city streets. Beyond the unlikelihood of such frenzied stampeding (given our overweight citizenry), there’s the fact that the entire planet is about to be destroyed. It would thus seem that no earthly destination should offer any particular advantage. Why budge?
At least an impact cataclysm is astronomically possible. It’s even likely, given enough time. Everyone is aware that it has happened before. When the author appeared on David Letterman’s late-night talk show, the first thing the host did was hold up a black meteorite he had just been handed and ask, “So what are the chances some big meteorite has my name on it? And that we’re all screwed?” He obviously thought the idea was amusing, not terrifying.
Equally humorous are several other possible future cataclysms that are popular with worriers, chief among them the idea that Earth’s poles will flip and destroy all life. The pole-flipping disaster is an issue that astronomers are periodically asked about, and the author routinely fields questions about it when appearing on monthly radio call-in programs.
This is a supposed cataclysm we can have some fun with because, although it sounds ominous, it is not an actual threat.
Like the meteor-impact scenario, reversals of the poles are events that have indeed happened to our planet before, many times. Scientists have recorded 184 magnetic-field reversals in the past eighty-three million years. But anyone wondering about pole flips has to clarify. Which poles? There are two pairs of poles, so you’ll have to be specific about which of these has you worried. The poles most people are aware of are the poles of rotation—that is, the geographical poles, the poles around which Earth rotates, one of which is where Santa lives. These are the places farthest north and south. Those poles do shift annually, but by less than a city block.
But there’s another set of poles, and those can shift rather quickly. These are the magnetic poles. Since most people who worry about pole shifts don’t know which poles they’re fretting about, here’s a quick review.
The Earth’s magnetic north pole, where magnetic-field lines dive vertically into the ground and toward which compasses point, currently sits five hundred miles from the geographic North Pole around which the planet rotates. It’s just west of Ellesmere Island in northern Canada, where, except for a small contingent of the Canadian military, nobody in his or her right mind has ever lived. This spot was first located by explorer James Clark Ross in 1831. There’s no buoy or marker there because the magnetic pole moves. Indeed, it’s been moving faster and faster lately. Since 1900, the magnetic north pole has migrated six hundred and fifty miles. In the past forty years, the rate has accelerated from five miles a year to thirty-seven miles a year. That’s sixteen feet per hour. The cause: motion in Earth’s liquid iron outer core.
We know the historic direction of our magnetic poles because when volcanic lava solidifies, the iron in it aligns with Earth’s magnetism. Such basaltic rocks reveal that our planet’s field reverses its north–south orientation haphazardly and does it on average a few times each million years. The time period for each new direction of north or south is known as a chron, and a chron can last for millions of years or, as in one historic case, change twice in just fifty thousand years. The average chron lasts four hundred and fifty thousand years. Some folks fear that the next flip is imminent, despite the fact that we’ve been living in the same chron for the past seven hundred and eighty thousand years. There’s no reason it should happen this century, even though Earth’s magnetism has weakened mysteriously by 10 percent since 1850.
But just as important, such magnetic-pole reversals have never matched the times of mass animal extinctions, so obviously, they don’t hurt anyone. And the process of reversal usually requires somewhere between a thousand and ten thousand years, so it’s not anything that can happen over a cup of coffee or even over a decade, although the most recent chron change appears to have completed its switch in under a century, which is extraordinarily rapid. Since then, people have grown accustomed to compass needles pointing where they presently do, to the north.
But something very weird did happen just forty-one thousand years ago, during the last ice age. The poles flipped completely, but the change lasted only four hundred and forty years and then returned back to the way things were and are now—and while the poles were reversing, Earth’s overall magnetic field dropped to just one-twentieth of its normal strength. (Experts still regard the current chron as having lasted seven hundred and eighty thousand years, despite this quick back-and-forth shift.)
Bizarre. But mostly harmless. The fossil record shows no mass extinctions or biosphere troubles during that time, other than the fact that it was an ice age, so it was freezing cold.
As to the geographic poles, those other poles, they never shift suddenly, but they do continuously migrate in a pivot called the Chandler wobble, moving up to a hundred feet every 433 days or so. The poles more or less return to where they started. A big earthquake can throw them off by a few feet (and speed up our daily spin by a millionth of a second), but the main causes of migrating poles are temperature, salinity, and pressure changes deep in the oceans.
Since the geographical poles roam, so must the equator.
In 2007, your author visited the Ecuadoran government’s equator monument outside the capital city of Quito. Beloved by tourists, the place features an enormous four-story obelisk with an equator line marked by stones and earsplitting salsa music blaring from speakers 24-7. Unfortunately, thanks to sloppy surveying, the monument is in the wrong place. A quarter of a mile away stands a popular private museum that claims to be the real GPS equator, and it has its own equator line. But the director of that museum, after learning he was being interviewed by an American science journalist, admitted that that line was not accurate either. The true equator, he insisted, was on a vacant lot a couple of hundred yards north.
But even if someone painted a third line there, it would have to be as broad as a California freeway in order to enclose the true, ever-shifting equator that migrates thanks to the Chandler wobble.
So, sure, worry about the poles flipping if you have nothing better to fret about. But first you have to find them.