Why do stars twinkle in the night sky?
Stars seem to glimmer, changing intensity. When you look up at them, you are viewing them through 100 miles of atmosphere, and because they are so far away they appear no more than tiny dots of light. these tiny points refract through the atmosphere catching dust particles and water vapour, causing the star to flash or twinkle. stars closer to the horizon have more atmosphere to shine through, causing them to twinkle more. Strangely planets do not twinkle, this is due to them reflecting light, and the fact that they are a lot closer.
