PASSPORT TO THE SOLAR SYSTEM: Educators Star Census

Star Census Activity Sheet

"Twinkle, Twinkle, Little Star"

Have you ever wondered what makes a star twinkle? On the next clear night look at a bright star.

How many blinks does it make in 10 seconds?

Look at the moon, an airplane or a bright planet at night. Do these objects twinkle?

A star is a point of light. It is so far away that even the largest telescope cannot show the star's disk. The atmosphere changing between the star and your eye causes starlight to twinkle.

Make these predictions about twinkling:

a. Do stars lower in the sky or higher, twinkle more?
b. Do stars twinkle more on a windy night, or a still night?
c. Do stars twinkle more at sea level or on a mountain top?
d. Do stars also change color as they twinkle?

Hint: Count star blink rates to answer the first question.

Share your data with students in other locations to answer the remaining questions.

"Seeing" is the term astronomers use to describe the steadiness of images. "Seeing" is best when the twinkling is least. When the seeing is good, astronomers can collect better data about the brightness and color of distant stars and galaxies.

Estimate how many stars you can see at night?
Do you see more stars in the city, or out in the country?
Do you see more stars on a moonless night or when there's a full moon?

Star Census Student Worksheet Measuring Activity Teacher Tips Star Data Student Work