Are we all going to die?
There are people throughout the world who are very worried about 2012. There have been dozens of books written and countless webpages devoted to 2012, along with a major film1 Although there is something that will happen in 2012 that has the potential to cause harm (look under Something Awesome in 2012), we will look at some of the most common claims about 2012 - good and bad.
Why 2012? Blame the Maya (or those who invoke the Maya). The Maya were an advanced civilization that existed in this hemisphere before the Spanish conquest. Their math and astronomy was very sophisticated for a civilization with only stone-age tech - they had no copper, iron or bronze. Their calendar in particular was very complex with multiple interlocking lengths of time. Another innovation of the Maya is a continuous day count over a long period known as the Long Count. One of the more famous Maya city-states has their Long Count end on December 21, 2012. Well, maybe, It's a bit complicated.
So Who Were the Maya, Anyway?
The Maya were great mathematicians and devoted skywatchers. Their knowledge of astronomy was vast and precise, especially where cycles of the planet Venus were concerned. The most tragic thing about the Maya is how little is known about them. Although the Maya still exist, they have changed their ways from the days when they built great pyramids and other stone buildings. Only a few documents survive from their entire civilization, so our knowledge about them is very incomplete. We also know that they saw three stars in Orion (Rigel, Alnitak, Saiph) as representing the three stones of a traditional Mayan hearth. The Orion Nebula - M42 - represented the fire in the hearth (see below).
Although their collapse is connected to climate change, it is now thought that they didn't decline very quickly. An earlier believed sudden "disappearance" made the Maya seem more mysterious and allowed people from all over the world to project their own culture onto them. A basic example is maps. Many ideas about the Maya involve non-Maya reading maps or charts into Maya ruins and stonework. But there is no evidence that the Maya ever used something similar to what we call a map - a scaled two dimensional representation of three dimensional space.
A great achievement of Mayan mathematics was the Long Count. As the name implies, this is a calendar that uses very large cycles of days to mark time. Unlike the West, which uses a base-ten in its counting, the Maya use a base-twenty. So it's not surprising that the Long Count is arranged in multiples of twenty. The basic unit is the day, or k'in. Twenty k'ins were an Uinal. Eighteen uinals were a tun, which corresponds to about a year (360 k'in). Twenty tuns were a Katun. Twenty katuns were a Baktun. Finally, thirteen baktuns was the extant of the whole cycle (in the Chichen Itza version), about equal to 5125 years. A sample Long Count date (for January 6, 720) appears below:
(or baktun 9, katun 14, tun 8, uinal 4, k'in 0)
The Maya also had other calendar cycles, such as the 260 day tzolkin and the 365 day haab, showing they were well aware of the actual length of the year.
The Maya had very precise astronomical abilities not because of esoteric forces, alien contact or lost technology, but because they possessed a type of single-mindedness that is almost extinct in the modern world. The eclipse cycle took a long time to figure out in ancient times because the cycle is 18 yr, 11.3333 days. It's the 0.3333 days that's the problem. It means that an eclipse that happened in the last cycle will fall on a different part of Earth (0.3333 day difference) in the new cycle. To get the same eclipse happening near the same place, 56 years (or three cycles) have to pass. In ancient times, it was rare for someone who remembered the first eclipse to get to see the second. In spite of these problems, the Chinese and Babylonians both worked it out. For the Maya to have the accurate value they found for the sidereal period of the Moon or the synodic period of Venus they had to observe many times over a period of many years. Venus takes eight years in its cycle to return to the same place in the sky at (almost) the same day of the year. Working out these cycles required enormous effort over many years, showing just how dedicated to observational astronomy the Maya were.
Since the Maya Long Count has a beginning, the cycle can be backtracked to its beginning, which was on August 11th (or 13th), 3113 bce. No one thinks that the Long Count was used in Central America five thousand years ago, anymore than people think that early Christians had a calendar using AD. Clearly both dating systems were created long after the start of their cycles. The oldest known inscriptions showing Long Count dates come from the 7th baktun (late 1st century bce), about three thousand years after the beginning of the Long Count. Astronomy uses a similar method for telling time: the Julian Date. That's a cycle that starts in 4713 bce, yet wasn't first used until thousands of years later. Like the Long Count, it counts days but unlike the Long Count it doesn't have any higher level of organization like katuns or baktuns.
Why would the Maya use a system that is tied to a date thousands of years before their culture began? It's a common desire in many cultures to want to be connected to the past in a grand way - deep time - partly to validate the culture and partly to give extra authority to those in charge. It also gives a hope that there will be a future, because the dating system goes so far back it's hard to imagine it won't continue on.
Now what does all this have to do with 2012? That is when the (Chichen Itza version) Long Count cycle ends. Specifically on December 21st (or 23rd) 2012. However, not all Maya used the same Long Count system. In the Maya city-state of Coba, they used many cycles bigger than katuns, such as piktuns, kalabtuns, etc (see below). In this system, the cycle won't end until 4.1 X 1028 years in the future. To the Coba Maya, 2012 was (and is) not significant.
A Gnostic Tradition
There is an ancient tradition in most religions (including Christianity) that salvation lies with knowledge. This alleged knowledge is secret (often ancient) and only initiates after study, prayer or meditation have a chance of gaining this knowledge which is needed for salvation or union with the divine. The people who searched for this knowledge in early Christianity called themselves Gnostics. This idea was considered very heretical to the early Catholic Church, as their view was that these gnostically questing adepts should not be allowed to "roll their own" theology. The Church also didn't like the implication that those who couldn't gain this knowledge were shut out of salvation. Other religions have either incorporated these ideas directly into the religion (Hinduism), started out with it being an important part of that religion (Buddhism), or lived with it uneasily (Sufi Muslims). Today, gnostic ideas still pop up, an recent example is the success of Dan Brown and his Da Vinci Code, which searches for clues (in Renaissance Art) to the life and legacy of Jesus.
Much of gnosis is tied to interpreting sacred texts after sifting through them for clues to this hidden knowledge. This often involves epic amounts of numerology and finding connections by manipulating numbers in sacred texts. A classic example would be the "number of the Beast" in the book of Revelation.
2012 Prelude: Harmonic Convergence
Some of the people (José Argüelles, in particular) claiming that 2012 is significant were also involved with something called the Harmonic Convergence. This was connected to a planetary lineup in August 1987 of the Sun, Moon and four planets. Someone who really wanted to stretch this could point out that Eastern Europe broke free of the Soviet Union a few years later and the Soviet Union itself imploded a few years after that. That's pretty big, but Harmonic Convergence promoters were claiming something far grander: The end of war, a new age of peace and a change of consciousness. Things were supposed to change for the better all over the world as we would be liberated from the evil technology that is destroying us and perhaps helpful aliens would then assist us. This has yet to happen. Argüelles and his supporters would say that the final chapter is yet to be written. Such a concept is also referred to as the Singularity, which some people connected with science believe may happen in the future. But this would be brought about by the "western" technology Mr. Argüelles thinks we should be liberated from, so it's unlikely he would approve of this version of consciousness change.
Predictions of Cosmic Consciousness
Not all claims about 2012 are depressing or catastrophic. Many newage spokespeople claim that the end of the Long Count is a time for us to reconnect to the cosmos. To leave behind our manifold useless distractions and focus on making ourselves a more better people in a more better world. The McKenna brothers (Terence is the more famous of the two) literally tripped out across the Amazon in Brazil and are early claimants of the significance of 2012. Also in this group is the aforementioned José Argüelles as well as John Major Jenkins. For these mystics, 2012 is the time when human consciousness will rise as part of a fast evolutionary shift in human ethics and aspirations. A time for celebration, not doom.
There is, however, a problem. It is common for these mystics to appropriate the language of science for their own ends. Terence McKenna, for example, speaks of 2012 being part of a "fractal wave" that he calls Timewave Zero. Fractal wave is a common example of technobabble, the use of words that sound "sciency" without either understanding or even caring about their true meanings. Some 2012 mystics may even be aware and take advantage of the fact that their audiences won't know the difference. This is why they are ignored by people who actually do science. In the end, 2012 mystics try to take powerful transformative personal experiences they and others have had and shoehorn them into a rational, scientific paradigm. This impoverishes both the spiritual and the rational by trying to equate two very different realms of human experience.
Predictions of Doom
There are many claims that something bad will happen in December 2012. Some even claim multiple bad things, most of which are covered below. They can be grouped into four levels: terrestrial, solar, galactic and cosmic.
Terrestrial Doom: These claims are about something on or near Earth destroying us.
Magnetic fields: Earth's magnetic field is powerful.
It protects us from charged particles that the Sun gives off. It also provides protection from cosmic rays that seem to be everywhere in space. It also shuts down every couple hundred thousand years or so (it varies and the last time it did was 780,000 years ago). After it shuts down, it reverses polarity which means that the old north magnetic pole becomes the new south magnetic pole and vice versa. "Reverse polarity" is a phrase often used as technobabble on Star Trek, but it actually has a meaning. While Earth's magnetic field is down, the particles from the Sun and elsewhere find it easier to get through. Earth's not completely defenseless though. Our atmosphere absorbs some of this stuff as well. Recent studies show that Earth's magnetic field is weakening, but it will take thousands of years before it should matter to us. It will not disappear in the next few years. Also, life on Earth has existed for billions of years. It has gone through many times when the Earth's magnetic field was "off". It's still here. Our early primate ancestors survived the last reversal, so it can't be a world-ending event.
Flipping poles: The Earth has two sets of poles: rotational and magnetic.
When the magnetic field turns off, the magnetic poles reverse (see above). So Earth's magnetic field shuts off and reverses (or flips) on a regular basis without destroying the planet. The rotational poles of Earth are a different story. It takes great force (torque) to change the tilt of Earth's rotational axis even slightly, because Earth spins so fast and has a large amount of angular momentum - the same thing that keeps a moving motorcycle from falling over while turning. Spinning objects resist having their poles moved. There is no evidence that Earth's rotational axis has ever flipped, even if it does change a bit over 26,000 years due to precession.
Crustal Displacement: This is an old alternative to the Theory of Plate Tectonics that tried to explain how continents could move.
It had little credibility then (1959) due to its proponent (Charles Hapgood) having no mechanism to offer explaining how it worked. Alfred Wegener, a pioneer of plate tectonics, had the same problem but geologists eventually worked out a mechanism that has been tested extensively. This even includes bouncing lasers off reflectors on the Moon, left by the Apollo astronauts, in order to measure the amount the continents move each year. There is a wide variety of evidence from lunar laser ranging to magnetic sampling of old rocks (showing magnetic field reversals mentioned above) to back up plate tectonics. No such evidence exists for crustal displacement. This is why it was abandoned by scientists. Those who still advocate it are not geologists and likely never heard of it before the movie 2012 came out (which mentions it). Perhaps some of these advocates don't think astronauts landed on the Moon either - which would make it hard to explain how the reflectors researchers bounce their lasers off of got there (and yes, they are there).
Climate Change: This is definitely going to be a problem for our civilization this century.
There is also increasing evidence that civilizations in the past were hit hard or even crushed by climate change, such as the Norse Greenland colonies (1300 - 1400 ce), the first farmers (8000 yrs ago), the Akkadian empire along with first Indus river valley civilization (about 2000 bce), and even the Maya themselves (800 - 900 ce). There is also evidence that climate change can happen much faster than previously thought, within a few decades or even less. But there is no evidence that the climate will shift so dramatically by 2012 that it will destroy humanity. As for whether a climate change could threaten humanity later on, that is very possible. The reason why many people are worried about 2012 is that some threats mentioned by doomsters are quite real. There's just no particular reason for them to arrive in 2012.
Solar Doom: These claims are about things happening inside our Solar System that will destroy us.
Sun will get us: The Sun has an eleven year cycle of sunspots, connected to its magnetic field reversing every eleven or twenty-two years depending on how important polarity is to your definition of "reverse".
Other stars show similar periods of activity. When the Sun has the most sunspots, it is the most active. When there is low solar activity (few sunspots), the Earth seems to get colder. Although this connection has some evidence to support it, no one has come up with a physical process that would tie the temperatures on Earth to solar activity. The Sun also has poorly understood longer periods of activity such as one that led to the Maunder Minimum. The Sun's normal cycle would be at its sunspot peak in 2012 or 2013. However, the Sun has recently been showing much less activity than normal (see the image above). It's had far fewer sunspots than normal even though it should be well towards solar maximum. Only in 2010 have any sunspots shown up at all, and still fewer than predicted.
Planetary lineup: They are as common as weeds.
Some recent major ones: 1982, 1987 (mentioned above), 1995, 2000, 2002, 2007. If you don't remember any of these, the doomsters would prefer it remain that way. There was a minor industry built around the 1982 lineup connected to a book called the Jupiter Effect. The May 2000 lineup caused many predictions of doom, perhaps because the date was 5/5/00. There is a big problem even defining what a planetary lineup is. The planets never lineup in a straight line, at best they get close to each other in the sky. Issue #1: How close is close enough? In the sky at the same time? Then they have to be within 180 degrees of each other, which isn't that rare. Issue #2: How many planets are required? Half? Most? All? In every planet lineup date given above, at least a few planets were missing. This brings us to 2012. There will be a planetary lineup on December 21, but it's a rather poor one. Only Mercury, Venus and Mars will be near the Sun (Pluto too, if you still consider it a planet). Saturn will be far to the west while Uranus and Neptune will be far to the east (it's one of those wide lineups). The largest and most massive planet of all, Jupiter, won't be anywhere near the rest. See for yourself here. Enter the date 12/21/12 at that site.
Rogue planet: About ten years ago, there was a woman named Nancy Lieder who claimed that we were all going to die in May 2003.
Her basis for this rested on her certainty that there was a rogue planet far beyond the edge of our Solar System that came through our neck of the woods very rarely, tearing up everything as it went. She even named this rogue planet Nibiru, based on some unrealistic interpretations of Sumerian cylinder seals by Zecharia Sitchin. Sitchin's story is even stranger and more can be found here. If there were a rogue planet hurtling toward the inner Solar System, it would have been seen by millions of people with telescopes who watch the sky constantly. Not to mention the robotic telescopes that do automated sky searches. Few comets escape their view. Some doom claimants try to get around this unpleasant fact by claiming that Nibiru is "always on the opposite side of the Sun" from us, so from our point of view it is always lost in the Sun's glare. The problem is, in order for that to happen, it would have to share the Earth's orbit. Which means it's in a stable situation, and not racing to our doom across the Solar System. The point is: if such an object were anywhere close to where doomsters say it will be in 2012, it would've been detected by now by its gravitational effects on other planets as well as by direct visual observation. It seems many 2012 doomsters are ignorant of just how well astronomical technology works in detecting faint, distant objects. Consider that we can actually take photos of planets around other stars, which is difficult given the one billion factor difference in brightness between star and orbiting planet. If we can see Fomalhaut B, which is over twenty light years away, we can detect an object much closer and as massive.
Galactic Doom: These claims are about things happening in our Galaxy that will destroy us.
Galactic Alignment: Some claim that the Maya knew the location of the center of our Galaxy and knew that at the end of their Long Count the location of the (Northern Hemisphere) winter solstice would be closest to the galactic center. John Major Jenkins is a prominent supporter of this idea. He believes that this will herald a consciousness transformation, so he is not a doomster. His claim about the Maya knowing all this is based on a few questionable alignments in a place that wasn't actually a Maya city. Further, whether the Maya knew about precession is a hotly debated question. Given their devotion to skywatching, it is possible they knew. The center of the galaxy is a different issue. Finding just the Galactic Equator is hard, never mind the actual Galactic Center. A picture of the Galactic center and the region around it is below:
In visible light (which is all the Maya had to work with), it is very hard to find the center of the Galaxy. William Herschel famously tried to locate it using star counts of different patches of the Milky Way (what we see of our Galaxy). The star counts were roughly the same everywhere he looked, so he wrongly concluded that we were near the Galactic center. In the 20th century, the center was first roughly located by watching the motion of globular clusters then later more precisely determined by seeing it in radio light. How could the Maya have known its location without a radio telescope? The winter solstice is near the galactic center, so the Sun comes close to the galactic center each year in December. On December 21, 2012 they will come this close (the galactic center is the beige target circle):
The position of the winter solstice changes over time because of precession. Yet 2012 is not when the Galactic center and winter solstice will be at their closest as that has actually already happened: in 1998. Whatever the significance of this alignment, it has little connection to 2012.
Black hole death: There is a massive black hole at the center of our Galaxy that has a mass about four million times greater than our Sun.
It is very powerful and is no doubt a threat to a number of stars that orbit very close by. However, it is about 28,000 light years away from us. This is important for two reasons: 1). It's very far away. 2). It can't do anything now that will affect us in a few years. The second reason is very important: in order for something at the center of the Galaxy to affect us in 2012, it would've had to have happened 28,000 years ago! A good question is what could the black hole at the center of our Galaxy do that could affect Earth out in the boondocks of the Galaxy? It's too far away for gravity to do anything noticeable and even a massive explosion of many supernovas or a sudden increase in activity caused by the black hole shredding a nearby star (nearby to the black hole, not Earth) would have little effect this far away.
Supernovas: Very massive stars explode as supernovas.
They have played the only role in making every heavy element on the Periodic Table. Recent studies imply that heavy elements determine which stars can form planets and what those planets are like. Supernovas are very violent as expected in a star that actually explodes. They create cosmic rays and release an entire galaxy's worth of light within a few weeks. Being near one is very bad. Some 2012 claimers of doom argue that the destruction Earth faces will be from a supernova in 2012. Supernovas surely give off enough energy to harm us, yet there is no star close enough to us to be a threat that can become a supernova.
Cosmic Doom: These claims involve the end of the Universe (which will wipe Earth out in passing).
Just like the book said: The Book of Revelation in the Bible predicts the end of the Universe (but says nothing directly about 2012).
It draws heavily on imagery in the Old Testament Book of Daniel and is taken literally by tens of millions in the Christian world. The problem is that Revelation is not written in same way as 1 Chronicles or Acts. The language is a forest of metaphors atop a mountain range of symbols. This inevitably makes it subject to many different interpretations. Early Gnostics spent much time trying to "figure out" Revelation, to the point where the Catholic Church hesitated keeping it in the Bible because of their low opinion of Gnostic theology and threat of Gnostic teaching to their authority. Numerology is often invoked here, the Number of the Beast being a famous example. Most scholars think the "Beast" refers to the Roman emperor Nero, who was no fan of early Christians. But a literal analysis could apply the label of the "Beast" to many people throughout history (such as Ronald Reagan) using arbitrary rules of interpretation, because interpreting the meaning is very subjective. Examining everything connected to the Book of Revelation is far beyond the point of this website, but there is no direct connection between Revelation and the Maya or 2012. Those who predict doom using Revelation and shoehorn 2012 as the date for the end are using only their own personal interpretation.
Gamma-ray bursters: There were once objects that made supernovas seem pathetic by comparison.
Astronomers still see these flares, called Gamma Ray Bursters, in the distant early Universe. The powerful version of these objects could indeed destroy the Earth even from a distance of 28,000 light years. Fortunately for Earth, all of these objects are very far beyond our Galaxy. The less violent ones, which still exist today, could have a negative effect on life on Earth. Some scientists suspect they may have played a role in at least one mass extinction in Earth's history, about 450 million years ago. Yet life has existed on Earth for billions of years. Once again, this is a credible threat to life on Earth, but there's no reason for it to happen in 2012 as opposed to any other year.
Something Awesome in 2012
It's a bit strange that people who are utterly convinced that something (usually bad) is going to happen in 2012 rarely discuss a major event in the sky that will happen on June 5, 2012: The Transit of Venus.
This is where Venus crosses the face of the Sun. The danger mentioned earlier arises from looking at the Sun. If you project the image or use proper filters, you are safe. Transits of Venus only happen in pairs eight years apart every 121 years. The last one was in 2004 and was visible in part of the US, but the beginning of the 2012 transit will be visible to everyone in the US who has clear weather. During a transit, the disk of Venus is clearly visible on the face of the Sun. No telescope or binoculars are needed to see it, just proper protection for your eyes. For more information on this event that no one now living will see again, go here.
It seems that for decades, people in the west have been obsessed with the end of the world. David Morrison has dealt with many questions about 2012 recently, and he's noticed that people are changing their questions slightly and asking about what year the world will end, Such people are convinced that even if it isn't 2012, it could only be a few years (or maybe decades) after that. It's a colossal bit of arrogance to think that we are so important that it all has to end in our lifetimes. Generations of people now dust thought exactly the same thing. Yet Earth's still here. Although it will eventually be destroyed by the Sun in 3 billion or 4 billion years, short of us doing it ourselves, Earth's going to remain for some time. Yet there's no guarantee that humans will be around.
Blasts from the past: Prophets of doom rarely keep score of their predictions and there's good reason why.
This also applies to prophets of good things.
They are wrong almost all of the time. These doomsters often don't care, as the author of the book titled 88 Reasons why the Rapture Will Be in 1988, went on to write The Final Shout: Rapture Report 1989 and 75% of the Bible is Future as of 21 November 1995 as well as The Complete Solution to the Book of Revelation (1996). This author might have continued this indefinitely, but the world did end for him in 2001 in an author existence failure. Clearly people like this are very much hoping you aren't keeping score. Doomsters were obviously wrong 100% of the time about the end of the world, but they also make related predictions that are vague enough to appear plausible - or at least possible - to some. For more information about failed past predictions (in a Christian context) look here. Still, the world will end someday. Even if our species avoids death by climate shift, suicide or industrial accident, the Sun will one day stop fusing hydrogen and move off the Main Sequence on its way to becoming a red giant star. At that point the Earth will be inside it and be very unpleasant to all concerned.
Why? The more important question is why this obsession over the end of the world continues in spite of centuries of false alarms? A related question is why historians break up history by wars: The inter-war period (1919-1939), the post-war period (1945 - Now), the antebellum period (Before 1861). Perhaps simply because it's exciting and fun. The end of things is big and dramatic and personal. A recent example would be the collapse of the Soviet Union. For those who live in the margins of society, perhaps feeling powerless to change the world or even their lives, The End is a time when everyone will go down regardless of wealth, power or privilege. This can give a bit of schadenfreude to those unhappy about their own lives. For others, thinking about The End gives them a sense of control or access to secret "insider information." For still another group of people, it could just be the desire for attention or the wish to participate in (or lead) a new order of things. If the world truly ended, of course, there would be no new order. Yet few doomsters claim the utter annihilation of all life or all humanity. Who would then buy their books? Selling books should also be considered as a big reason for some authors to flog doom. Some 2012 books have been bestsellers.
Real threats: We live in an age where our destruction is a very real possibility, but haven't we always? The difference today is that destruction can be self-inflicted. Nuclear war, biological weapons, economic collapse, the list is long and depressing. There is another thing that is new in these forms of doom. Humans have power over them. To stop (or mitigate) climate change, don't have a Bigfoot-sized carbon footprint. Economic collapse? Stop using credit and stay out of debt, including mortgages. A new plague? Move out into the country and get self-sufficient. The forms of doom that are self-inflicted can be prevented or at least softened. Not easily, but if the alternative is death then it's no choice at all.
The never ending end: A safe prediction that can be made is that people will be predicting doom after 2012. Prophecy is an unsinkable rubber duck, in James Randi's memorable phrase, that keeps popping up again and again after every failure. Whether the years 2060 and 2076 (religion-based) or 2025 (technology/gray goo/nanotech based), new dates will be set, new books will be written and sold. New prophets of doom will also surely arise to proclaim that this time is really it!
1 Full disclosure: According to the actor John Billingsley (who played Professor West in the film), the movie 2012 was originally titled "Goodbye Atlantis" and the whole 2012 subplot was written into the movie as an afterthought (this doesn't explain why the film was so bad).
Technobabble: The use of scientific words - or similar sounding words - by a writer/speaker to convince a reader/listener that the writer/speaker is discussing science. The effect is to confuse or obfuscate the reader/listener. Often used in science fiction and by pseudoscientists.
Precession: The 26,000 year cycle of the sky caused by a wobble in the Earth's spin. The position of everything in the sky shifts mostly because of this cycle and since astronomy coordinate systems are tied to the path of the Sun in the sky (from our point of view), other things can move with respect to that path.
Solstice: The point in the sky where the Sun stops moving north (summer for the Northern Hemisphere) or the other point in the sky where the Sun stops moving south (winter for the Northern Hemisphere). The Northern Hemisphere's winter solstice is the point that comes close to the Galactic center.
Aveni, Anthony. The End of Time. University Press of Colorado. Boulder, CO. 2009. ISBN-10: 0870819615.
Grofe, Michael. "Fruit from the Chocolate Tree II: From the Haab to Precession", IMS Explorer, June 17, 2009. 1+.
Kirsch, Jonathan. A History of the End of the World. HarperOne. New York. 2006. ISBN-10: 0060816988
Linden, Eugene. The Winds of Change: Climate, Weather, and the Destruction of Civilizations. Simon & Schuster. New York. 2006. ISBN-10: 0684863529
Morrison, David. Personal interview, Oct 31, 2010.
Plait, Phil. "The Planet X Saga: Introduction", Bad Astronomy Blog. http://www.badastronomy.com/bad/misc/planetx/
Questions? Contact me (Liam McDaid, SCC Astronomy Coordinator)