Twinkle twinkle little star

If you catch yourself looking up at the night sky on a clear night you will see a bunch of stars in your field of view. Upon more careful observation you notice that some of these stars twinkle, or glimmer in the sky. What causes this effect? Why do stars do this and how can we explain it? Let's look into why we experience this eye catching phenomenon and what causes it.

It's all about the atmosphere

The twinkle effect we see from stars is actually not caused by the stars, as the light they shine flies straight towards us from its point of origin. Instead what causes that glimmer effect is the turbulence of the atmosphere of Earth. When the light from a star reaches our Earth's atmosphere it gets slightly bent sometimes which causes that toTwinkle StarCredit: Wikimedia Commons appear as a twinkle in our eye. Since some of the light hits our eyes straight while others are hitting it slightly off because of the bend of our atmosphere it looks like it's glimmering when in reality it's not. The interesting this is when you look at stars that are straight up in the sky vs stars that are seen on the horizon. Stars that are seen on the horizon are going to twinkle much more frequently than stars that are directly above you as there is a much greater density of atmosphere and particles in the way from the star's light to our eyes. This is why there is a similar question to why we have red sunsets. The sun isn't redder when it gets to the horizon, it's just because the atmosphere projects more interference at the horizon. That's why the sun seems red at sunset, or why starks seem to twinkle more frequently at the horizon.

Optical illusions

This idea of having the light bent when it hits our eyes and gives off the illusion of the twinkle is something we as humans are fascinated with. Optical illusions mess with our perception of the sense of sight, which is exactly why when we find twinkling stars and other various tricks interesting because it seems out of reality in sorts. Have you ever noticed how on a hot summer day if you lookOptical IllusionCredit: down at the road ahead it looks wet? It's not because it's wet, but because of the optical illusion the heat of the air gives off making it appear soaked. This effect of light and waves that mess with our eyes and perception intrigues many people, and space is no different. If we were to get into a spaceship right now and head out of Earth's atmosphere we would notice that the twinkle effect would cease and we would see light from a star as solid unaltered light. Even though the light from a star travels millions of lightyears to reach our eyes, that light isn't altered one bit because space has no atmosphere to bend or mess with that light, but after it gets to Earth then it is altered.

The Universe

There are so many fascinating things the universe and space have to offer, and the twinkling star phenomenon we ask frequently about is just one of many. I will probably be writing more articles soon about more strange and amazing things we see and learn about in space, but for now I believe that this question that has been asked many times can finally be put to rest. It's not the light from the star, but the atmosphere of Earth that messes with our perception and therefore we get that effect.