When you look up at the night sky , almost every star appears to fluctuate quickly in brightness , or blink in and out , or careen positions slightly . The little stars are twinkling , twinkling ( the scientific term isscintillationorastronomical scintillation ) , but why ?
There used to be two theory about twinkling . One held that Earth ’s atmosphere is the lawsuit . To get from the star to us , the starlight travels through layer of air . As the light enters each layer , it is refracted , or bent , at an angle subject on the temperature and density of that layer . Low frequency light is refracted at a smaller angle than higher frequency luminosity , so different colour of light wind up traveling different paths . On top of that , all that air moves around because of steer , solar convection , etc . , changing the light ’s already tortuous route . The result is that an pedestrian observer is seeing the gather refractions of the light as it arrives via different paths and perceive the star rapidly change brightness , size and position .
The other hypothesis had it that something encounter out towards the edge of the Solar System , like gas swarm , cause the instant in much the same way Earth ’s atmosphere might . object closer to Earth , like the Dominicus , do n’t winkle because their Christ Within does n’t have to pass through the clouds like stars ' light does .
All that needed to be done to essay the atmospheric state theory was get an observer beyond Earth ’s atm and have them face at a star . The debate was settled when Ronnie Walter " Quincy " Cunningham , an spaceman on the Apollo 7 mission , did just that . He afterward publishedImportance of reflexion That Stars Do n’t wink Outside the Earth ’s Atmosphere .
If the atmosphere causes twinkling , though , why do n’t planet , the moonlight and the sunlight sparkle ? Because they ’re closemouthed than stars . Stars are far enough off that their light appear to come up from a single head in the sky . With the moonlight , sun and some closer planet , visible radiation appears to come from a small disk in the sky and comes from multiple points . The light from each of these points is refracted just as much as the brightness from superstar , but these points have strength in numbers and the twinkling of one percentage point is easily masked by another , giving us a uniform , non - twinkling image .
