I’m taking a break from everything else I’m doing, because solar events are awesome. – the Sun has just belched out another big flare, ranking at M7.3. It’s certainly been a turbulent little star recently.
The info was tweeted about half an hour ago by Tamitha Skov, a NASA physicist, who mistook it at first for a more powerful X7.3 flare – which would have been the most powerful one so far this year. This image shows the flare’s area of effect:
Perhaps fortunately, her first reading was in error. It’s not an X7.3 but an M7.3 flare. Rather a lot less severe!
Tamitha Skov (@TamithaSkov) May 22, 2013
Even so, it highlights an interesting thing which we haven’t had to face yet on Earth. Electronics and wireless communications have come a long way since the last time the Sun was at solar maximum. Powerful solar flares can interfere with radio communications on Earth, and I’m not sure if we fully understand the extent to which we could be affected.
While X7.3 would have been powerful, it’s far from what the Sun can put out at maximum. Flares up to X28 have been recorded in the past – the most violent solar storm on record, in 1859, succeeded in setting fire to telegraph pylons and giving telegraph operators minor electric shocks due to induced current in the wires!
Solar flares are given a rating. A letter, A, B, C, M, or X from weakest to strongest, and a number. Just like the Richter scale, those numbers are logarithmic – so each number is twice as powerful as the last (i.e. X3 is twice is strong as X2). Weak A-class flares aren’t all that uncommon, but the strong X-class flares can have noticeable effects!
The most extreme flares (X20 and above) will actually disrupt high frequency radio signals on the entire sunlit side of Earth for several hours. This means that aircraft and ocean going vessels would be completely without HF radio communications, and other services like wifi and mobile phone signals may experience disruptions.
Even X1 flares can cause minor disruptions on the sunlit side of Earth for around an hour, and we’ve had several of those so far this year.
As the Sun powers into full solar maximum, you have to wonder how well modern electronics (together with our reliance on the internet and satellite communications) are going to cope.
Still… At least a flare looks very pretty. Flares may also be associated with coronal mass ejections (CMEs), which belch out protons, sometimes causing spectacular aurorae. With a large enough CME, those aurorae may even be visible quite far South!
(And yes, I know I misspelled “flare” in the title of this post. It’s a poor attempt at a play on words…)