The Solar Cycle

A solar cycle: a montage of ten years' worth of Yohkoh SXT images, demonstrating the variation in solar activity during a sunspot cycle, from after August 30, 1991, to September 6, 2001. Credit: the Yohkoh mission of ISAS (Japan) and NASA (US).

The evolution of our Sun will happen over the course of billions of years. While this timeline is not accessible for us to observe in our lifetime, the Sun’s cycle is! Although less impressive than the changes it will go through over its lifetime, the Sun will see some significant changes over a cyclical period of 11 years.

We have been observing sunspots on the solar surface for millennia, but it wasn’t until the 19th century that scientists started noticing a certain regularity in their appearance and abundance. These sunspots are regions of the Sun’s surface where intense magnetic activity reduces temperature. Although still very hot (2750 to 4250°C), they appear darker in contrast to the surrounding regions that are about 5500°C. They crop up in greater number during a solar maximum, and are often accompanied by solar flares or prominences — ejections of huge clouds of particles and energy from the surface of the Sun.

While the Sun appears considerably more active in ultraviolet light during a maximum, the total energy output only increases by about 0.1%. These maxima are thus not expected to impact global climates, although they can slightly affect some regional weather patterns. The last maximum occurred in 2000, and with a cycle of about 11 years (but which can vary from 9 to 14 years), that would put the next maximum right about the end of 2012: truly great fodder for all 2012-end-of-the-world believers. Happily, you can rest assured that the next solar maximum is of no threat to us, and we have gone through a great number of solar cycles without much of a hitch. While it is true that solar flares and more violent solar activity can sometimes disrupt some of our radio communication systems, we are greatly protected from any actual danger by our Earth’s magnetic field. On the upside, we also see a greater abundance of the beautiful aurora borealis in the polar skies! Furthermore, NASA scientists believe that the upcoming solar maximum may be the weakest one since 1928. Once again, Earth seems to have averted total destruction!

Meteors over Russia

A video of the meteor zipping through the air above Chelyabisnk, Russia. Video credit: Wikimedia Commons/Aleksandr Ivanov.

Small rocks enter the Earth’s atmosphere every single day. These are typically the size of a pebble and burn up quite harmlessly many tens of kilometers up into our atmosphere. At larger intervals of time, however, Earth is assaulted by much larger asteroids. On February 15th of this year at 9:20am local time, an asteroid estimated to weigh 11,000 tonnes entered the atmosphere over Chelyabinsk, Russia and subsequently exploded at a height of about 24 km, releasing the equivalent energy of 30 times that of the Hiroshima atomic bomb. The shockwaves that followed the bright explosion damaged upwards of 7,000 buildings and injured about 1,500 people. Now that everyone is only ever a few feet away from some sort of camera, the impressive event was extremely well documented. It is not, however, the first known event of its kind.

The Chelyabinsk meteor is the largest known object to have entered Earth’s atmosphere since what is known as the 1908 Tunguska Event. Meteor airbursts of this size occur every 100 years or so. The Tunguska Event luckily happened over a barren region in Siberia, where only very few eyewitnesses were reported to have seen a great flash of light and feeling a powerful shockwave that knocked them off their feet. The explosion may have been over 30 times more energetic than the Chelyabinsk meteor airburst. It registered on seismographs as an earthquake of 5.0 on the Richter scale and set the nightskies of Europe and Asia aglow for many nights. We can only theorise what may have happened had such an event occurred over a densely populated region, but the effects would most likely have been quite devastating. Later expeditions to the explosion site found entire forests of trees covering an area of 2,150 square kilometers completely scorched and knocked down from the blast.

Due to the remote location of this event, as well as the primitive state of our understanding of meteor behaviour at the time, a number of alternate theories have been proposed to explain the Tunguska Event. These range from a miniature black hole passing through the Earth to a giant pocket of natural gas being released from the Earth’s crust to Serbian inventor Nikola Tesla’s death ray experiment having gone awry. The meteor airburst theory remains the most scientifically supported one to date.

While these events are quite rare, it should be noted that the Chelyabinsk object was completely undetected before it exploded in our atmosphere. Perhaps the Universe is reminding us that we should keep a closer eye on it…

2012 Apocalypse via Galactic Alignment

The X-ray view of the supermassive black hole at the centre of the Milky Way Galaxy. Image credit: NASA/CXC/MIT/F. Baganoff, R. Shcherbakov et al.

This is the Doomsday Scenario I’ve personally encountered the most, perhaps because it deals with things seemingly less outrageous than giant planets slamming into our us? As things go about their merry way in space, orbiting about one another, certain alignments are bound to happen. As with anything rare (OMG I JUST SAW A BLACK CAT SLAM INTO A MIRROR UNDER A LADDER WHILE OPENING AN UMBRELLA INDOORS WHAT ARE THE ODDS???), people like giving some significance to these events. Partial planetary alignments occur now and again, but do you know what’s even scarier than a planet? Why, a supermassive black hole(Sagittarius A*, to close friends) at the centre of the Milky Way, of course! Silly you.

Some have been saying that the Mayan calendar has been constructed around the alignment of Earth, the Sun and the Galaxy’s centre, which they say will happen on December 21st 2012, at which point everything will explode, or something. Truth is, it’s not actually going to happen on that date. Even better, were it to happen, Sagittarius A* is just so darn far away from us that it wouldn’t matter. Despite being over a million times more massive than our Sun, the fact that it’s 30,000 light years away means its gravitational effect would be insignificant compared to the pull we feel from our Moon. Even betterer, the actual alignment happened in 1998, so… Unless you count Britney Spears releasing her hit song …Baby One More Time as the apocalypse, I think we came out of that alignment relatively unscathed. Chances are, the same will happen this December (is Britney due for a new album?).

2012 Apocalypse via the Maya Calendar

An engraved Mayan calendar. Image credit: Kim Alaniz / CC BY.

Next up in our apocalyptic adventure is a more general overview of why people have been freaking out in the last little while. With Y2K coming and going with no end of the world insight (well, I guess all this pollution isn’t that great, but I digress), people have been seeking some other importnt and alarming transition point in some calendar. When one was not found within our own Gregorian calendar, our prayers were answered when we delved in the ancient Maya calendar! 

Whereas our calendar is split up into weeks, months, years, centuries and millennia, the Mayans – and the Olmecs before them – split their calendar into different units.

1 day is a Kin

20 Kins is a Uinal

18 Uinals is a Tun (approximately a solar year)

20 Tun is a Ka'tun

20 Ka'tun is a Bak'tun

20 Bak'tun is a Pictun

[…]

All the way to 1 Alautun, which is 23,040,000,000 days, or Kins.

We are currently at the end of the 12th bak'tun since the beginning of our current age. This December 21st 2012 will be the moment when we enter the 13th bak'tun, denoted in the Long Count calendar as 13.0.0.0.0. There is very little evidence in the study of historic artifacts that would lead us to believe that a cataclysmic event is inevitable at this date. In fact, the Maya celebrated the end of each cycle, and welcomed the new bak'tun as a chance for renewal, much like we celebrate the end of every year by dropping giant globs of lightbulbs onto buildings, awkwardly kissing whomever happens to be closest to us at the time and counting our blessings.

The Maya have survived and celebrated previous changes of bak'tun. In their writings, they even speak of events that happen in their mythology far beyond December 21st 2012. There’s no reason to believe they knew something we don’t about some impending doom waiting for us at the end of this year. Breathe easy for now, and start saving your money for next Christmas, because it looks like we won’t be saved from the holiday gift giving season just yet!

The Royal Ontario Museum in Toronto is currently hosting a great temporary exhibit on The Maya Civilisation until April 9th. If you’re heading out there, you should definitely check it out! If you’d rather not leave your computer, but are still interested in learning more on the Maya calendar, read up on it right here, on my personal favourite resource: Wikipedia.

2012 Apocalypse via a Colliding Planet!

V838 Monocerotis, a variable star shrouded in a dusty halo. Image credit:  NASA and the Hubble Heritage Team (STScI/AURA).

Peppered over the year, we will be looking at different scenarios brought forward by a variety of people as how the year 2012 will bring about our demise. This month, we’ll be discussing the supposed collision of our own Earth and a planet named Nibiru, also known as Planet X. The Planet X hypothesis has been kicking around for a long time. As far back as the 19th century, scientists thought an unknown planet in the far reaches of our Solar System larger than Pluto was necessary to explain certain discrepancies in the orbits of Uranus and Neptune. These were later solved without the need for such a planet, and the issue has mostly been laid to rest in the scientific community.

Enter one Nancy Lieder in 1995. Convinced she has been elected by a race of aliens inhabiting the Zeta Reticuli star system to warn us of our impending doom, she has been hard at work spreading the good word over the internet. Initially, she stated that the planet Nibiru, supposedly 4 times the size of the Earth, would be sweeping through our Solar System on May 2003 before finally colliding with Earth. She states that even a near collision could be deadly, as interactions with Nibiru’s magnetic field would stop our own planet from rotating for an extended period of time, causing terrible, horrible things like displacement of the Earth’s crust. Obviously, May 2003 came and went and nothing of the sort happened. Logically, Lieder opted to argue that she had lied about this first date to “fool the establishment”… whatever that means. But if you’ve always dreamt of witnessing a planetary collision from a particularly close vantage point, never fear! “Experts” now say this mammoth event should happen in December 2012. Lucky us!

Obviously, there’s no real proof that any such planet with any such malevolent intentions is out there in our Solar System. An object of such a size would have been visible by now, yet there have been no visual confirmations of Nibiru or Planet X or Kerplowksiker. Of course, if NASA is part of “the establishment”, then it might all be a coverup. Furthermore, the orbit of this planet as described by Lieder has been found to be highly unstable by credible astronomers, and it would have been ejected from our Solar System within a million years of its creation. There are basically a bunch of reasons why we shouldn’t worry about this scenario coming to pass. If you’re curious, you can read up a little more on this topic here.

If you’re worried about our 2012 scenarios, and just can’t wait for me to talk about them, go through this neat NASA FAQ to ease your mind.

Until next month! Just because the world isn’t ending this year doesn’t mean we shouldn’t make the most of it!