Related by context. Frequent words. (Click for all words.) 59 gravitational interactions 58 planetesimals 57 accretion disk 57 interstellar clouds 57 gravitationally bound 57 icy moons 57 gaseous planets 56 Andromeda galaxy 56 Kuiper belt 56 WASP #b 56 colliding galaxies 56 orbiting planets 55 moonlets 55 dwarf galaxies 55 Oort cloud 55 red supergiant 55 dwarf galaxy 55 protoplanetary disk 55 spiral galaxies 54 planetary nebulae 54 stellar nurseries 54 supernova explosion 54 extrasolar 54 galaxy NGC 54 Cosmic rays 54 photosphere 54 protostar 54 interstellar dust 53 impactors 53 Oort Cloud 53 planet orbits 53 active galactic nuclei 53 aurorae 52 exosphere 52 Earthlike 52 circular orbits 52 comet tail 52 rocky planets 52 Eta Carinae 52 Galileo spacecraft 52 X ray emission 52 planetary nebula 52 moon Enceladus 52 spiral galaxy 52 meteoroids 52 protoplanetary disks 52 neutron stars 51 Earth magnetosphere 51 distant galaxy 51 By Riva Froymovich 51 planets 51 faraway galaxies 51 supernova explosions 51 supernova remnants 51 helium atoms 51 magnetars 51 lunar craters 51 Martian dust 51 gravitationally 51 distant galaxies 51 polar craters 51 protostars 51 planet orbiting 51 ringed planet 51 Magellanic Clouds 51 meteoroid 51 nebulas 50 ejecta 50 elliptical galaxies 50 Saturn rings 50 solar nebula 50 atomic nuclei 50 undersea volcanoes 50 nebulae 50 Kuiper Belt objects 50 lava tubes 50 comet Shoemaker Levy 50 terrestrial planets 50 star Gliese 50 visible wavelengths 50 spatial dimensions 50 Hawking radiation 50 mesosphere 50 polar vortex 50 Andromeda Galaxy 50 galaxy clusters 50 Jupiter Saturn Uranus 50 habitable zones 50 planets circling 50 celestial object 50 planet Uranus 50 cosmic dust 50 HD #b [002] 50 ionized gas 50 hot Jupiters 49 galaxies 49 atomic particles 49 Gamma rays 49 vortices 49 supernova remnant 49 globular cluster