As auroras boreais ocorrem quando as radiações solares colidem com os gases na atmosfera superior da Terra, produzindo ondas de luz que enchem o céu de cor. É um fenómeno observável em especial nos círculos polares e é conhecido por “luzes do norte” e “luzes do sul”, de acordo com o local onde ocorre — circulo polar ártico ou antártico. As auroras são visíveis durante todo o ano e estão relacionadas com as emissões de radiação solar e com o campo magnético da Terra, cujas variações fazem com que, por vezes, as auroras sejam visíveis a latitudes mais a sul (ou a norte) que o habitual. Foi o que aconteceu este fim de semana, onde o fenómeno iluminou o céu de vários países.
https://twitter.com/cnni/status/511007704995733504/
Skywatchers capture spectacular #AuroraBorealis over Northern Ireland http://t.co/1jUpym3PkE pic.twitter.com/21uH7yrlfX
— BBC News (UK) (@BBCNews) September 13, 2014
Alright folks here is a first look of the #aurora at office in Caribou, ME. #mewx #AuroraBorealis pic.twitter.com/alB8qcLyKx
— NWS Caribou (@NWSCaribou) September 13, 2014
We saw incredible images of #AuroraBorealis this weekend. It reminded us of a shoot we did in January! #Auris pic.twitter.com/PtAiEFhQnq
— ToyotaUK (@ToyotaUK) September 15, 2014
Wow, tonight's Northern Lights from Mt. Washington, NH. Via @WXKnapper. #AuroraBorealis pic.twitter.com/wzeo02bJWg
— The Boston Calendar (@TheBostonCal) September 13, 2014
Amazing shot last night of #AuroraBorealis in New Hampshire, US by Ryan Knapp #3eWeather pic.twitter.com/1eDvr9Z37f
— Deric Ó hArtagáinTV (@deric_tv) September 13, 2014
How to see the Northern Lights in #Seattle http://t.co/63aPAQwLuP #AuroraBorealis pic.twitter.com/Zkg7zMOkTI
— AlkiSurfShop (@AlkiSurfShop) September 13, 2014
From NOAA's Space Weather Prediction Center, for tonight. http://t.co/47PjpcklvK#AuroraBorealis pic.twitter.com/DDPsD3a3a7
— EarthSky (@earthskyscience) September 13, 2014
Northern lights : fine aurora borealis – Iceland by tobi500 #photography #auroraborealis pic.twitter.com/0Msi0FWAGp
— Jukka Heinovirta (@k009034) September 12, 2014
There's nothing like seeing the Northern Lights. @AuroraMAX #NorthernLights #AuroraBorealis #solarflare pic.twitter.com/ZwpkBdzHxy
— Barry Butler (@barrybutler9) September 12, 2014