Book 4, Question 93 · Video
Why Do Stars Twinkle?
Stars don't really blink on and off! It's our air that is jumpy. Pockets of warmer and cooler air bend the starlight as it comes in, so the point of light seems to dance.
Read the full answer →What Crafty Clover says in this video
Intro
Hey there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why do stars twinkle?
The Big Idea
Stars don't really blink on and off! It's our air that is jumpy. Pockets of warmer and cooler air bend the starlight as it comes in, so the point of light seems to dance. The twinkle happens in the air, not in the star.
Star Shines, Light Enters Air
Step one: the star shines, and its light enters our air. A star is so far away that it looks like a tiny pinpoint of light. That beam starts a very long trip, and in the last moment, it enters our atmosphere. A pinpoint is easy to push around.
The Air Wobbles
Step two: the air wobbles. Air is never perfectly still. Warm and cool pockets mix and swirl, and each pocket bends light a little differently. So the beam's path is constantly changing.
Your Eye Sees a Twinkle
Step three: your eye sees a twinkle. Because the beam wiggles, the star's brightness and position seem to jump around. Planets look like tiny disks, so their light averages out, and they twinkle less. That is one way to tell a planet from a star. A steady bright dot might be a planet!
A Closer Look
Let's take a closer look at twinkling! A star sends a tiny pinpoint of light. The warm and cool air pockets bend the beam on its way down. And your eye sees the bent light as a twinkle.
Quick Facts
Quick facts! City lights hide faint stars, and darker yards show more twinkles. A bright star that barely twinkles may be a planet. Telescopes on mountains sit above some of the jumpy air. Astronauts above the air see steady stars.
Think Like a Scientist
Now, think like a scientist! With a grown-up, compare a star near the horizon and one overhead. Which one danced more? What extra air did the low star's light travel through? On night walks, use a light for the path, not for the sky.
Outro
Twinkle, twinkle, little star, now we know just what you are! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!