Measuring The Distance To The Moon With Photographs

Scott's Step By Step Guide to Measuring the distance to the moon using photographs.

Things you will need:

Cameras

2 People Thousands of miles apart

Good weather, and night skies for both observers.

A Computer!

Preparation:

Get your camera and learn how to take photos showing the moon and the stars nearby, the moon will be overexposed if you can see the stars, it's easier when the moon is not full.

Agree on a date and time that both observers will use, make sure you account for differing timezones.

Makea duplicate of this sheet so you can plug in your own measurements.

Taking the photos:

Ideally communicate with your partner so that you both have the same time, take the photograps and make sure you can see the moon plus at least 2 other stars or planets

Figure out what the two stars or planets are, and make sure both observers are getting them in the same frame, note down their names.

Analyzing the data.

Calculate the distance between the two reference objects, this will provide the scale for the images.

Calculate the baseline distance between the two observers.

Add both of these values to the image analysis sheet.

For Each Photo input the x/y coordinates on the image for the 2 reference objects and the moon.

If you did it all correctly you should have an estimate of the distance to the moon!

For finding your way around the sky I recommend https://stellarium-web.org/ but there are many other options you can use, just be sure to match the time in the viewer to the time the images were taken.

Example Image from Marin, California at 9:30pm Pacific Time on August 1st 2020

https://twitter.com/DJSnM/status/1289780660630990849?s=20

And simultaneously, from Rio de Janiero in Brazil

https://twitter.com/brigidogabriel/status/1289781942120878080?s=20