Ask A Scientist© Astronomy Archive

Author:      helen m vonderheide
Why do stars twinkle?

Response #:  1 of 1
Author:      jasjeet s bagla
Earth's atmosphere is turbulent.  When light from stars passes through the
atmosphere, it gets refracted from the straight line path.  As a result of
this, the light reaches us from different points in the sky.  These direc-
tions are actually very close to each other but not the same.  This shifting
of the image results in what we call twinkling.  Twinkling can effect
objects with size smaller than the shift caused by atmosphere, therefore,
only stars twinkle and not the Sun, Moon or the Planets.