Related by context. Frequent words. (Click for all words.) 66 magnetosphere 64 cosmic ray 63 spacetime 63 gamma ray burst 62 interstellar medium 60 magnetic fields 60 quasar 60 heliosphere 60 supernova explosion 60 astrophysical 60 neutrino 60 dynamical 60 neutron star 60 galaxy clusters 60 gamma ray bursts 60 solar flares 60 gravitational waves 59 supermassive black hole 58 ionosphere 58 nucleation 58 vortices 58 atmospheric circulation 58 cosmic rays 58 distant galaxies 58 volcanism 58 galaxy cluster 58 CMEs 58 supernovae 57 quasars 57 crustal 57 supermassive black holes 57 photons 57 gamma rays 57 Enceladus 57 auroras 56 oscillations 56 neutrinos 56 magnetization 56 subatomic particles 56 gravitational 56 pulsar 56 laser pulse 56 quantum mechanical 55 convective 55 galaxies 55 corona 55 neutron stars 55 geomagnetic 55 cosmic microwave background 55 nuclei 55 electrons 54 Iapetus 54 atoms 54 sunspots 54 atomic nuclei 54 cometary 54 chemical reactions 54 electron spin 54 globular clusters 54 comets 54 nebula 54 troposphere 54 NASA Cassini spacecraft 53 perturbations 53 outer planets 53 brown dwarfs 53 XMM Newton 53 comet 53 aurora 53 infrared radiation 53 supernova 53 distant galaxy 53 X ray Observatory 53 redshift 53 oscillation 53 THEMIS 53 interstellar dust 53 exoplanets 53 electron 52 WMAP 52 Saturn rings 52 spectroscopic 52 brown dwarf 52 laser pulses 52 electromagnetic 52 planet orbiting 52 atmospheric chemistry 52 sunspot 52 rocky planets 52 Cassini 52 radioactive decay 52 photon 52 Einstein theory 52 planets 52 magma 52 angular momentum 51 geomagnetic field 51 pulsars 51 high temperature superconductors 51 planetary 51 extrasolar planets