An unprecedented and stunning aurora could be visible in Cambridge again this weekend after the phenomenon illuminated the sky on Friday night. “This is what Fantasia aspires to!” said a Chesterton resident on social media alongside a photo of the stronger-than-expected G5 strength geomagnetic storm. “OMG, I can’t believe I just took these outside my home… What an incredible lightshow!” said Marc Carmel, a Duxford resident. A G5 geomagnetic storm is the strongest level of the phenomena known as aurora borealis. Aurora displays occur when charged particles collide with gases in the Earth’s at…