Brightly lit object appeared at 6:48pm at 20° above horizon approximately center between polaris and cassiopia

Brightly lit object, intense white brightness at center but indiscernable shape, however it had a massive light blue glow surrounding the object, in the shape of a two-armed spiral that didnt change but appeared larger as it approached. It started from the north, at about a fist and a half higher than the horizon, it was so bright it illuminated the tree tops at my neighbor's property. As it moved south-west it became a bit higher maybe 30° above horizon as measured by closed fist. It appeared to be moving very slowly and at a low altitude, it moved about 90°-100° west taking about 9 minutes to move from its appearance in the north to disapearance in the west. It didn't disappear per se, it faded and appeared smaller as it got further away. No sound was heard from the object at all. Very clear skies tonight as many stars and constellations are visible however there is a light low mist or fog. Immediatly after observing its appearance I brought my ten year old son outside to witness it with me. We have no conclusion what it could be, but both agree it was unique and spectacular.