The universe is a dark, empty place. Despite being almost infinite, the view in almost every direction is darkness. However, here and there bright stars, galaxies and nebulae break this black monotony. Without the eternal presence of these constellations, astronomy would be a boring affair. Remarkably, even though these star systems shift over time, we see the same patterns in the sky as our ancestors thousands of years ago would have seen.
That is why some rare astronomical events can invoke such primordial feelings. Extremely bright supernovae create new points of light brighter than all other stars combined, and some comets can shine more intensely than a full moon and stretch across the entire night sky. While such occurrences are rare, they litter the history books; comets and supernovae have been documented back to more than 2000 years ago. The Chinese civilisation in particular noted hundreds of these events, including Halley’s Comet in 240BC and the Crab supernova in 1054AD. Historically such events have been seen as an astrological prediction of great changes, and even as recently as 1997, the appearance of comet Hale Bopp led to 39 members of a small Californian religious sect to commit suicide.
Unusually, two such events have been predicted for 2013. In March the comet Panstarrs will sweep in from the outer solar system and pass close to the Sun. It is predicted that this close call with the Sun will heat the comet’s icy interior enough to create a bright comet tail that will be visible in the Northern hemisphere.
The pièce de résistance, however, is likely to be Comet Ison. Due in late November 2013, this large ball of ice and rock has steadily been making its way from the cold edge of the solar system over the past few months. Not only will it be passing perishingly close to the surface of the Sun creating a bright tail, Ison’s orbit also takes it close to Earth as it leaves the inner solar system. Many have predicted that it could be the greatest comet in over a decade, leaving a tail brighter than the full moon across the Northern Hemisphere. Despite only just passing the orbit of Jupiter, recent observations have already detected a tail on the comet suggesting predictions of its potential brightness are not just hyperbole.
The other great cosmic events, supernovae, are almost impossible to predict. These flashes of light are the death-throws of giant stars as they come to the end of their life. The last ‘local’ event occurred in 1987 more than 150,000 light years away. On average, the Milky Way galaxy sees a handful of such explosions each century, although no more than six have been spotted in the last thousand years. While this does not mean the chances of a supernova occurring this year have increased, there is certainly the distinct possibility that the night sky may be set alight by both comets in our solar system and stellar explosions hundreds of light-years away.
Throughout human history, the sky above was seen and studied by all. Modern life, however, with its day-glow orange skies and sheltered buildings, has all but cut this link to the night. There is hope though that the cosmic events predicted this year can turn a universe of dark, immobile constellations into a spectacle of bright and dynamic lights. This may the spark needed to rekindle that instinctual passion in the universe above.
