On 7 December 2015, the YouTube Channel "Section 51" published a video purportedly showing a UFO entering an inter-dimensional portal. An accompanying article claimed that the event was filmed in Geneva, Switzerland, near the Large Hadron Collider at CERN, the European Organization for Nuclear Research.Geneva, Switzerland. US tourists filmed UFO/strange orb entering Interdimensional Portal in the sky of Geneva, just over CERN area.
The video soon became fodder for publications such as Yahoo News, The Mirror, and The Daily Mail, all of whom reported that the clip had stirred online debate about the authenticity of the video.
While it's true that some internet commentators are claiming that a UFO really did enter an inter-dimensional portal over the Large Hadron Collider, that simply isn't the case. This is a fake video created by a YouTube channel that specializes in hoax videos.
Section 51 has previously published fake videos purportedly showing "ancient pyramids in Antarctica," a "giant UFO over parliament". Section 51 is so prolific that it even promises to provide "new UFO sightings every Monday & Thursday."