What is a Lightyear? Activity

Students will explore and discover what a lightyear is with this What is a Lightyear? Activity.

Teacher Instructions:

The unit of astronomical distance, light-years, can be a difficult but essential concept for students to comprehend. This activity will get your students moving and, hopefully, help them understand what a light-year is.

Step One:

Give your definition of light-years to your students and explain why this is important for them to understand. I like to tell my students that Proxima Centauri is our nearest star, and it is 154.243 light years away. Let’s pretend we have a friend on Proxima Centauri right now. If we went outside and waved to him, when would he see us waving? He would not see us waving until 4.243 years from now. that is because it takes light 4.243 years to reach him.

Step Two:

Make copies of the table attached and hand out to your students. Clear some room in your class or go outside. Line your students up and tell them to run for one second. Have them look at how far they traveled and tell them that that is considered their run-second. Have them line up again and tell them to start running. Time them running for one minute. Have them measure the distance they traveled. Tell them to record the distance on their recording table next to “my run minute.” Bring them back into class and instruct them to figure out their run-week, run-month, and run-year. Conclude by telling your students that their run-year is how far they would travel in one year. A light-year is how far light travels in one year.

A 3 page printable PDF