Related by context. Frequent words. (Click for all words.) 70 perigee 67 sunspot cycle 66 supermoon 65 substorms 62 Perseid meteor shower 60 autumnal equinox 60 gamma ray burst 60 Geminids 59 meteor shower 59 occultation 59 geomagnetic storms 59 ecliptic 59 moonrise 58 sunspot activity 58 meteoroid 58 geomagnetic storm 58 meteor showers 58 Perseids 58 coronal mass ejection 58 X ray emission 57 spring equinox 57 equinox 57 ringed planet 57 equinoxes 57 Leonids 56 supernova explosion 56 planet orbits 56 Earth magnetosphere 56 cosmic ray 56 Eta Carinae 56 COROT 56 outer planets 56 vernal equinox 56 solar flares 56 geomagnetic 55 constellation Leo 55 Gliese #g 55 annular eclipse 55 super Earths 55 gravitational lensing 55 coronal mass ejections 55 geomagnetic field 55 constellation Perseus 55 magnetar 54 MARSIS 54 sunspot numbers 54 GRBs 54 extrasolar planet 53 Kuiper belt 53 comet 53 unaided eye 53 HD #b [002] 53 moon 53 ejecta 53 volcanism 53 Halley Comet 52 Comet Tempel 1 52 equatorial Pacific 52 Opportunity rover 52 planet orbiting 52 auroral 52 orbiting telescope 52 moon Charon 52 CMEs 52 volcanically active 52 cosmic microwave background 52 celestial object 52 Itokawa 52 magnetosphere 52 comet Hartley 2 52 Saturn moon Enceladus 52 sunspot 52 gamma ray bursts 52 sunspots 52 Crab Nebula 52 geologically active 51 comet nucleus 51 Saturn moons 51 meteors 51 thundersnow 51 meteoroids 51 Lunar Eclipse 51 Sedna 51 rover Opportunity 51 mid latitudes 51 heaviest precipitation 51 aurora 51 thermosphere 51 elliptical orbit 51 rocky planets 51 radioactive decay 51 Titan Saturn 51 Sunspots 51 partial lunar eclipse 51 quark gluon plasma 51 distant galaxy 51 auroras 51 circular orbit 51 equatorial regions 50 extrasolar planets 50 particle collisions