Is it a plane? Is it a satellite? Is it a galaxy? Is it aliens? A strange blue spiral lit up the skies over Europe on Monday night (March 24), causing residents of the U.K. and other European countries like Croatia, Poland, and Hungary to flood social media with photos and videos, along with requests to identify this weird light. Some users even speculated that the spiral could be the work of aliens! Space.com can reveal the identity of the object behind this spectacular event, and unfortunately (possibly reassuringly), rather than being the work of extraterrestrial visitors, it's a bit...