Related by context. Frequent words. (Click for all words.) 59 contrail 53 vortices 51 vapor trail 47 water vapor 47 plumes 47 aerosols 47 sonic booms 46 gravitational waves 46 cosmic rays 45 sonic boom 45 clouds 45 Saturn rings 45 sunspots 44 plume 44 updrafts 43 ionosphere 43 droplets 42 troposphere 42 meteors 42 particles 42 atmospheric 42 cosmic radiation 42 ice crystals 41 supernovas 41 convective 41 bluish 41 vapor cloud 41 volcanic eruptions 41 nebulae 41 greenhouse warming 41 craters 40 albedo 40 cosmic ray 40 supernovae 40 gamma ray bursts 40 lava flows 40 skies 40 gamma rays 40 gamma ray burst 40 magnetic fields 40 quasar 40 aurora 39 blobs 39 vapor 39 splotches 39 corona 39 oscillations 39 distant galaxies 39 optical illusion 39 nebula 39 galaxies 39 laser pulses 39 auroras 39 comet 39 comets 39 UFOs 39 Perseids 39 cosmic microwave background 39 sky 39 neutron star 39 astrophysicists 38 haze 38 computer simulations 38 filaments 38 meteor 38 ozone 38 solar flares 38 fog 38 airborne particles 38 trajectories 38 cosmologists 38 glaciers 38 soot 37 nanotubes 37 sunspot 37 quasars 37 photons 37 flying saucers 37 neutron stars 37 wisps 37 ozone depletion 37 blue skies 37 Enceladus 37 Soot 37 Martian atmosphere 37 mist 37 volcanic activity 37 condensation 37 supermassive black hole 37 reflectance 37 wind shear 36 raindrops 36 celestial objects 36 UV radiation 36 blotches 36 celestial bodies 36 atmospheric carbon dioxide 36 spores 36 electrons 36 dust particles 36 cloudiness