St Elmo's fire - B777 windscreen light show!

We were treated to an amazing light show on our way from Nairobi to London!
The skies were literally electric that night!
So what is it? Is it DANGEROUS?!
(Note: strictly this isn't St. Elmo's Fire - that is another phenomenon also linked to highly charged, static atmospheres, but it is generally accepted and called this among aviation enthusiasts and pilots too!)

[@phileagle8432]

Wow this is amazing isn’t it? So beautiful and well done for capturing it!

[@ot3254]

Genuine question - were you worried at all? Or perfectly normal?!

[@takeflightwithhelen]

Not worried at all!

[@mustafashulqamy1844]

Do you have LinkedIn?