I USUALLY try to vary my topic from month to month but my February reflection on the aurora brought in a couple of intriguing queries from readers.
One was about "the Carrington Event" and what effect, if any, the recurrence of such a phenomenon would have on the modern world. The other was sparked by a US newspaper headline from last year proclaiming, in very large letters, "NASA warning of solar superstorm in 2012".
The two are closely related in that the Carrington Event, named after the British astronomer who made scientific observations of it, was arguably the greatest solar outburst of recent history. The flare, a great mass of hot plasma unleashed by a giant sunspot on August 28, 1959, caused an extraordinary display of auroral activity which was visible not just in the high latitudes but as far south as the Gulf of Mexico in the Americas and over Mediterranean areas in the old world.
As well as providing our forebears with an incredible light show for several days - brighter than moonlight across much of the surface of the Earth, and much more colourful - the flare and its associated coronal mass emission imparted so much energy to the Earth's magnetic field that very strange things started happening to what was then a state-of-the -art communication system - the telegraph.
The system failed across great swathes of Europe and America with telegraph poles all over the place, and the paper used to record the Morse imprints at the most sophisticated transmission stations, being set on fire. And the machines kept on churning out nonsensical signals despite being disconnected from their power sources.
COULD something like this happen again? The answer has to be yes, given that we owe our lives to being right next door to a turbulent star, the workings of which we do not fully understand and which we have only just begun to observe systematically.
Indeed, major solar storms, though not of quite the same magnitude, have occurred on many occasions right up to modern times including October 29 and November 4, 2003, when numerous satellite sensors were overwhelmed by incoming radiation.
Something on the scale of the Carrington Event, were it to happen today, would unquestionably have a much greater impact than it did in the 19th century. We now rely to an extraordinary degree on satellite transmissions, internet connections, sophisticated telephony, and vast, delicately balanced, electricity grids. A solar superstorm could have the capability to disrupt any or all of these with deleterious effects on our shaky economies.
Is a solar superstorm likely in 2012? Closer reading of the literature on the subject reveals that the prediction for greatly increased solar activity was originally made for 2011, then revised for 2012 and has now been postponed till 2013, so the predictors are hedging their bets.
In the past, solar activity has always built up very rapidly towards its climax when powerful auroral season have occurred but, this time around, the sun is stuttering to life very slowly and fitfully.
Let's just wait and see what happens!
Jim A. Johnston would welcome suggestions for future topics for the Skywatching column. He may be contacted by e-mail at firstname.lastname@example.org