Related by context. Frequent words. (Click for all words.) 62 perihelion 61 obliquity 61 WASP #b 59 exosphere 58 heavily cratered 58 orbits 58 highly elliptical orbit 57 polar vortex 57 ultraviolet wavelengths 57 solar nebula 57 photosphere 56 circular orbit 56 planet Uranus 56 CoRoT 56 lithosphere 56 solar irradiance 56 visible wavelengths 55 perigee 55 GeV 55 icy moons 55 planet orbits 55 Olympus Mons 55 HAT P 55 solar corona 55 mesosphere 55 TrES 54 GPa 54 geoid 54 micrometre 54 elliptical orbit 54 tropopause 54 ecliptic 54 anisotropy 54 irradiance 54 z = 54 gravitational lens 53 circular orbits 53 geosynchronous 53 phonon 53 Venusian 53 asteroid Vesta 53 metallicity 53 keV 53 moon Enceladus 53 HD #b [002] 52 interplanetary spacecraft 52 Cepheids 52 meteoroids 52 attosecond 52 cm -1 52 isotope ratios 52 martian 52 sunspot cycle 52 kelvin 52 -# degrees Fahrenheit [002] 52 interferometers 52 protoplanetary disk 52 radioactive decay 52 equinoxes 52 Kuiper Belt objects 52 redshift 52 electron density 52 Gamma rays 52 Ultraviolet radiation 52 Lagrangian 51 galaxy NGC 51 meteorite impacts 51 coronal hole 51 noctilucent clouds 51 dynamical 51 photometry 51 innermost planet 51 COROT 51 Jupiter Saturn 51 Kuiper belt 51 redshifts 51 gaseous planets 51 gravitational attraction 51 curvature 51 albedo 51 Iapetus 51 Gamma ray bursts 51 ellipsoid 51 supernova explosion 50 electron spins 50 detectability 50 Tharsis 50 Uranus 50 spacetime 50 planetesimals 50 morphologies 50 Crab Nebula 50 substorm 50 planetary nebulae 50 photometer 50 regolith 50 isotopic composition 50 γ 50 atmospheric CO 50 tropospheric 50 aerosol particles