Today is a good day to watch the skies. Not only are the last three Concorde flights due in quick succession at London Heathrow, but even bigger forces are gathering overhead. The Sun has grown a couple of the largest, most active sunspots seen for a long time, and they're spewing huge amounts of energetic crud in mighty dollops of cosmic plasma. These coronal mass ejections (CMEs) can cause all manner of interesting effects if they hit Earth -- a big one yesterday may just strike a glancing blow, but another one from the day before is heading straight for us. It's due to hit tonight.
The Earth's magnetic field deflects nearly all the nasty stuff, but the side effects can be spectacular. Radio conditions have been terrible all week, and there's a fair chance of some really good aurora this evening -- possibly visible from most of the UK. In extreme cases -- and these CMEs may measure up -- huge induced voltage surges can knock out power lines, satellites can be disabled and navigation systems may go wonky. There's also increased radiation on airline flights -- and the higher you go, the more there is.
None goes higher than Concorde. There's something apt in the plane's last flights happening on a day when its natural environment at 57,000 feet is the most hostile it's been for years. With its radio knocked out by the crippled ionosphere, the thin air around it swarming with radiation and its navigation in the lap of the Sun God, the old lady is getting quite a send-off from the sea in which she swam.