Related by context. Frequent words. (Click for all words.) 58 Earth magnetosphere 58 WASP #b 57 magnetic reconnection 57 heliosphere 56 spacetime 56 meteoroid 56 elliptical orbit 55 lithosphere 55 electron density 55 perigee 55 sunspot cycle 54 thermosphere 54 atmospheric turbulence 54 circular orbit 54 anisotropy 54 comet nucleus 54 radial velocity 54 COROT 53 interplanetary spacecraft 53 gravitational wave 53 GOCE 53 impactor 53 geomagnetic field 53 cosmic ray 53 X ray emission 53 heliosheath 53 planet orbits 53 solar corona 53 polar vortex 53 magnetosphere 53 gravitational 53 ejecta 52 angular momentum 52 magnetic flux 52 gravitationally 52 orbiting telescope 52 innermost planet 52 Oort Cloud 52 comet tail 52 magnetar 52 accretion disk 52 Hawking radiation 52 dynamical 52 gravitational lensing 52 muon 52 ionosphere 52 ion propulsion 52 wavefront 52 interferometer 52 gravitational attraction 51 gravitational tug 51 Arctic Oscillation 51 cosmological constant 51 microlensing 51 Haumea 51 solar irradiance 51 substorms 51 radiative forcing 51 observable universe 51 Iapetus 51 Itokawa 51 electron spins 51 ecliptic 51 CloudSat 51 Saturn rings 51 galaxy formation 51 aerobraking 50 subatomic particle 50 HiRISE camera 50 LCROSS 50 Earth orbit 50 gamma ray burst 50 radar altimeter 50 ITCZ 50 albedo 50 Sedna 50 asteroid 50 troposphere 50 adaptive optics 50 orbit 50 celestial object 50 planetoid 50 photonic crystal 50 orbits 50 Hubble observations 50 magnetization 50 Brownian motion 49 solar nebula 49 Coriolis 49 attosecond 49 radiative 49 aerosol particles 49 terahertz radiation 49 cosmic microwave background 49 photometer 49 orbiting spacecraft 49 perturbations 49 frequency comb 49 Einstein theory 49 Eta Carinae 49 coronal mass ejection