Why do stars seem to twinkle in the night sky while planets shine steadily? This fascinating phenomenon comes down to how light interacts with Earth's atmosphere. Stars twinkle because they are so far away that their light reaches us as a single point. Atmospheric irregularities cause this light to bend and shimmer, creating the "twinkling" effect. Planets, however, appear steadier since their larger size in the sky smooths out these atmospheric effects. | The Brain Maze