Navigate to [https://afterglow.skynet.unc.edu/en/workbench](https://afterglow.skynet.unc.edu/en/workbench)

Change the display settings (eye icon) to see Venus as clearly as possible.

In a new tab, open the lab report document so you can see the table for your data.

Back in Afterglow click "Plotter" (the line icon)

Make sure to leave "Centroid clicks" off.

Centroid clicks
Planet Centroiding
Interpolate pixels
Sync Plot Across Files

For Illuminated Angular DISTANCE, measure across the planet.

Change tabs to your report. Paste the data into your table.

Return to Afterglow. Measure the Angular DIAMETER of the planet by measuring the widest visible part.

Change tabs back to your report. Paste the data into your table.

Open <https://www.desmos.com/scientific>

Divide the Illuminated DISTANCE by the Angular DIAMETER. You MUST get a number that is less than 1.

Change tabs back to your report. Copy the answer into the final column of your data table.

Repeat all these steps for each image of Venus.

Desmos

Google Docs is a cloud-based document editing and collaboration platform. Learn how to change your doc margins, delete pages from docs, strikethrough text, and much more.

Afterglow: Measure Angular Distance vs Angular Phase of Venus