The Lesson 6 Lab: Cosmic Distance Ladder introduces a few of the primary methods used by astronomers to determine astronomical distances. Parallax is introduced first, spectroscopic parallax, main sequence fitting, variable stars, and supernova are all discussed. You will see how some of these methods are used to measure the distances to nearby stars while others are used to determine distances to very distant galaxies. In Chapter 14, we apply these techniques to determine distances to other solar systems as we explore the planets we find there. This lab will also show us how early astronomers gaged the distances to planets here in our own solar system.

Getting started with Lesson 6 Lab: Cosmic Distance Ladder:

The Cosmic Distance Ladder Module consists of material on seven different distance determination techniques. Four of the techniques have external simulators in addition to the background pages. You are encouraged to work through the material for each technique before moving on to the next technique.

• First, select the following link and work through the background sections on Radar Ranging, Parallax, Distance Modulus, Main Sequence Fitting, Supernova, Cepheids, and Hubble’s Law under the ‘Main Content’ section at:
  • Cosmic Distance Ladder Lab
• Next, open the following link and familiarize yourself with the capabilities of the simulator through experimentation:
  • Parallax Explorer Simulator
• You will also utilize the following simulators:
  • Supernova Light Fitting Curve Simulator
  • Cluster Fitting Simulator
  • Spectroscopic Parallax Simulator
• After familiarizing yourself with the simulation interactive, follow instructions and answer questions in the Lesson 6 – Lab Cosmic Distance Ladder Worksheet.

Note: The Lab Simulators require Flash Player which is integrated into Windows 10 and work best with Internet Explorer (IE). To avoid technical issues IE is recommended for running the simulations. If you try another browser you will need to set up flash player options for that browser yourself. For example, if you are using Chrome, go to the upper left of the URL browser entry, select “Not Secure” then select “Allow” to give Chrome permission to open the simulator.