Related by context. Frequent words. (Click for all words.) 63 galaxy formation 63 astronomical objects 61 active galactic nuclei 60 planetary nebulae 60 spectroscopic 59 astrophysical 58 aerosol particles 58 Cepheids 58 galaxy clusters 58 nebulas 58 solar corona 57 ultraviolet wavelengths 57 gravitational waves 57 optical wavelengths 57 morphologies 57 distant galaxy 57 radial velocity 57 colliders 57 gravitational lensing 57 GRBs 57 supernova remnants 57 Hubble observations 57 spacetime 57 photometry 56 geoid 56 WIMPs 56 habitable planets 56 magnetic reconnection 56 magnetars 56 VIRTIS 56 moonlets 56 Kuiper belt 56 magnetic fields 56 elliptical galaxies 56 gravitational wave 56 rocky planets 56 bathymetry 56 Earth magnetosphere 55 novae 55 distant galaxies 55 atomic particles 55 colliding galaxies 55 galaxies 55 singularities 55 X ray emission 55 interferometric 55 Type Ia supernovae 55 baryons 55 subatomic 55 Oort Cloud 55 protoplanetary disk 55 dynamical 55 comet nucleus 55 Earthlike 55 neutron stars 55 celestial object 55 auroral 55 Gamma ray bursts 55 numerical simulations 55 planets 54 globular clusters 54 electron density 54 accretion disk 54 supernova explosions 54 subatomic particles 54 substorm 54 quantum entanglement 54 Computer simulations 54 Keck telescope 54 nebulae 54 XMM Newton 54 photoluminescence 54 planetesimals 54 osmium 54 aurorae 54 biogeochemical 54 supernovae 54 lava tubes 54 underwater volcanoes 54 quasars 54 terrestrial planets 54 vortices 53 Cosmologists 53 interferometry 53 MERIS 53 habitable zones 53 Gamma rays 53 microstructures 53 optical microscopes 53 NASA Chandra 53 protostar 53 microscale 53 redshifts 53 quark gluon plasma 53 spectral signatures 53 isotope ratios 53 infrared spectroscopy 53 nuclei 53 X ray Observatory 53 galaxy cluster 53 isotopic composition