 Greetings and welcome to the Introduction to Astronomy. In this week's Misconception in Astronomy, we are going to look at the idea that stars twinkle. And find out, do stars actually twinkle themselves? So, do stars twinkle? That is our big question here. And the quick answer is no. Stars do not twinkle. Stars are not changing in brightness at all and are not jumping themselves. That's a star doing anything. We do notice stars twinkling. As you look in the image here, you can see that the star is changing a little bit and jumping around. But this has nothing to do with the star itself. This twinkling, or sometimes called scintillation, is caused by Earth's atmosphere instead. So, we do not see. What it does is the light path through the atmosphere changes. So, let's take a look at that, how that might work. And what we see is that the light paths coming from space are actually nice and smooth. So, here's what we see coming from space. Nice, smooth waves. The stars would be shining nice and steady. However, when that passes through Earth's atmosphere, then that distorts the waves. And that is what is causing the stars to twinkle. It makes them seem to jump around and makes them appear to twinkle. So, in reality, stars themselves are not doing any twinkling even though we're used to seeing things like this where a star may appear like it is twinkling. And you go out in a hazy night and you will see the stars twinkling. It's really the position slowly, quickly changing as those light paths go through different deformations within the atmosphere. If you were to go to the moon, for example, and observe these same stars, well, then the stars would just be nice and steady. There would be no twinkling if you were on the moon or in space. It is only Earth's atmosphere that causes the stars to appear to twinkle. And again, that is because of these distorted light paths as the waves pass through the turbulence in the Earth's atmosphere. This is why you see it mostly in the hot, hazy nights, say, of summer, because the atmosphere is more turbulent. The stars are much more settled on a very cold winter night when the atmosphere is more stable and that minimizes the amount of twinkling that would be seen. So, let's go ahead and finish up with our summary. And we said that stars do not twinkle by themselves. Their light is distorted when it passes through Earth's atmosphere. That is what is causing things to twinkle. If you get outside the atmosphere, there would be no twinkling of the stars. So that concludes this misconception on stars twinkling. We'll be back again next week for another misconception in astronomy. So until then, have a great day, everyone, and I will see you in class.