The 2012 Mayan prophecy of the end of the world is over - but that does not mean we have got it over with. There is something about to happen for which may not get more than 30 minutes warning.
A solar superstorm could trigger black-outs and knock out one in 10 satellites
Scientists have warned of the Solar Superstorm that occur every 200 years - the last happened in 1859.
On that occasion, Earth was hit by a tidal wave of energetic particles following a large solar flare. Induced currents caused by the blast sent sparks flying from telegraph pylons and caused fires.
Scientists are preparing for the event which could paralyze communications networks including GPS and mobile phones. Experts warn that the solar superstorm on the scale of the Carrington event is 'inevitable' and Britain should be prepared.
'Our message is: Don't panic, but do prepare - a solar superstorm will happen one day and we need to be ready for it.'
Currently an ageing satellite called Advanced Composition Explorer (ACE) provides around 15 minutes warning of a Coronal Mass Ejection (CME) - a huge plasma cloud of charged particles that causes the most damage during a solar storm.
Scientists are concerned about what will happen if Ace fails. A replacement for Ace, called Discover, is due to be launched by the American space agency Nasa in 2014.