Related by context. Frequent words. (Click for all words.) 58 Tunguska 56 Antarctic ozone 53 Chernobyl catastrophe 52 supervolcano 52 Chicxulub 52 megaquake 49 meteoroid 49 Lake Vostok 49 Chicxulub impact 48 supernova explosion 48 comet Shoemaker Levy 48 volcanic eruption 48 meteorite impacts 48 tremblor 48 Siberian permafrost 48 WASP #b 48 Cabeus crater 48 Tangshan earthquake 48 Toutatis 47 volcanic plume 47 Halley comet 47 Alpine glaciers 47 undersea volcanoes 47 WD5 47 Tycho Brahe 47 Typhoon Tokage 47 Galileo spacecraft 46 Volcanic eruptions 46 Ice Ages 46 RQ# 46 Cosmologists 46 Snowball Earth 46 glaciations 46 cosmonaut Yuri Gagarin 46 explosive decompression 46 Sayano Shushenskaya plant 45 icecap 45 Oort cloud 45 Gondwanaland 45 substorm 45 asteroid 45 magnitude earthquake 45 Supermoon 45 Lunokhod 45 lunar crater 45 paleoclimate 45 meteorite 45 ecological catastrophe 45 Ixtoc spill 45 Arctic permafrost 45 Higgs particle 45 Sputnik satellite 45 Deep Impact probe 45 Mongol invasion 45 Titan Saturn 45 Boslough 45 explosion 45 Earth ozone layer 44 Eric Rignot 44 crater 44 subatomic particle 44 supermoon 44 southernmost continent 44 satellite Sputnik 44 mass beaching 44 mass extinctions 44 moon Enceladus 44 Cagsawa 44 Great Kanto Earthquake 44 mesosphere 44 planet Uranus 44 Loma Prieta quake 44 ALH# 44 interplanetary spacecraft 44 thermonuclear explosion 44 meteor 44 supernova explosions 44 noctilucent clouds 44 Oort Cloud 44 geomagnetic storm 43 atomic nucleus 43 physicist Richard Feynman 43 red supergiant 43 NASA Stardust spacecraft 43 Ocean acidification 43 severe droughts 43 Centaur rocket 43 Strong quake jolts 43 microfossils 43 atmospheric methane 43 Lunar eclipse 43 horned dinosaur 43 Zasyadko mine 43 Antarctic ice 43 Beslan siege 43 solar nebula 43 orbiting Hubble Space Telescope 43 marine sediments 43 Eta Carinae 43 Iceland Eyjafjallajokull volcano 43 Sumbawa Island