Related by context. Frequent words. (Click for all words.) 45 UFO sighting 45 UFO sightings 41 events 40 phenomena 39 UFO 39 UFOs 38 statistical blip 37 sightings 37 coral bleaching 36 geomagnetic storm 36 event 36 occurrences 35 phenomenon 35 sunspot activity 34 upsurge 34 increase 34 Tunguska 33 incidents 33 meteor shower 33 MUFON 33 decline 33 flying saucers 33 incidences 32 occurring 32 sighting 32 happenings 32 occuring 32 spike 32 meteor showers 32 exponential growth 32 rise 32 occurance 32 mass extinctions 32 reduction 32 manmade global warming 31 decrease 31 alien abduction 31 developments 31 flying saucer 31 occurence 31 uptick 31 Incidents 31 outbreaks 31 tragedies 31 increases 31 accidents 31 Sightings 31 occurrence 31 paranormal activity 30 escalation 30 happening 30 reductions 30 mysterious disappearance 30 NASA Cassini spacecraft 30 incursion 30 detections 30 fluctuation 30 Enter keyword select 30 flash mobs 30 airshow 30 Fourth Kind 29 downward revision 29 blip 29 gradual erosion 29 downtick 29 sporting events 29 unveilings 29 symposiums 29 solar eclipses 29 cutbacks 29 astrophysical 29 gamma ray burst 29 hauntings 29 solar flares 29 gatherings 29 contrail 29 incident 29 gravitational waves 28 mortalities 28 alien invasion 28 eruption 28 announcements 28 Unsolved Mysteries 28 escalations 28 downward trend 28 meteor 28 incidence 28 upward trend 28 flyby 28 phenomenons 28 Fluctuations 28 fluctuations 28 deceleration 28 observances 28 epidemic 28 avian flu outbreak 28 upturn 28 exponential 28 commemorations 28 rises 27 deterioration