Related by context. Frequent words. (Click for all words.) 67 elliptical orbit 62 circular orbit 61 orbits 57 HD #b [002] 57 perigee 56 orbiting 56 gravitationally 56 distant galaxy 55 orbit 55 magnetosphere 54 neutron star 54 extrasolar planet 53 orbital 53 interstellar medium 53 Eta Carinae 53 planet orbiting 53 heliosphere 53 ringed planet 53 Sedna 53 galaxy cluster 53 supernova explosion 52 gravitational pull 52 polar orbit 52 X ray emission 52 gravitational 52 super Earths 52 Uranus 51 spiral galaxy 51 Earth orbit 51 atomic nuclei 51 interstellar space 51 Martian atmosphere 51 Large Magellanic Cloud 51 galaxy 51 Itokawa 51 outer planets 51 Iapetus 51 geosynchronous orbit 51 interstellar dust 51 comet nucleus 51 hot Jupiters 51 asteroid 51 magnetic fields 50 gamma ray burst 50 pulsar 50 Milky Way galaxy 50 nebula 50 cosmic ray 50 brown dwarf 50 comet 50 ionosphere 50 Kuiper Belt 50 exoplanet 50 Solar System 50 dwarf galaxy 50 terrestrial planets 49 exoplanets 49 umbra 49 Saturn rings 49 planets 49 Enceladus 49 Tempel 1 49 ionized 49 ejecta 49 corona 49 moon Titan 49 supernova 49 lunar orbit 49 spacetime 49 orbiting spacecraft 49 planets orbiting 49 Milky Way Galaxy 49 spacecraft 49 MESSENGER 48 orbited 48 XMM Newton 48 distant galaxies 48 NASA Cassini spacecraft 48 orbiting telescope 48 equatorial regions 48 asteroid belt 48 Milky Way 48 brown dwarfs 48 hydrogen atoms 48 spiral galaxies 48 Jupiter Saturn Uranus 48 Saturn moon 48 superfluid 48 comet Wild 48 supermassive black hole 48 atoms 48 radiative 47 rocky planets 47 thrusters 47 angular momentum 47 outer layers 47 oscillations 47 robotic spacecraft 47 impactor 47 cosmic rays 47 LCROSS