Results and thank you

Carolyn Kennett

Hello all 

I wanted to report back how close a result we got from our parallax project. 

We had 3 attempts.

The first in February:

We had a good response but mainly from the UK, the furthest image we had to use as a baseline for the Parallax was from Portugal, we saw this as a trial run. The resulting distance we calculated was 271734km and the Moon was 360461km away from Earth, so we were a whopping 24.6% out.

The second in March:

We got lots of images to use for the March attempt, including some lovely ones from the Abu Dhabi Observatory and one form the Philippines which really helped us get a better idea of the parallax shift. This resulted in a calculated distance of 340014km, the Moon at that time was 357122km away so just a 5.03% difference, which I thought was pretty amazing.

The third in April:

The final attempt in April was marred by clouds here in the UK, although I had clear skies in the southwest. We did have a number of US observers taking part including members of Flagstaff and Joe Pasachoff in New York, which made the whole thing seem pretty international. We got a resulting distance of 315736km, the Moon at this date was 356906km away, so we had a difference of 11.5% – pretty respectable.

So overall the second attempt had the closest result. There were lots of lessons learnt along the way, but we were pretty pleased with the results. We really enjoyed this and may run something similar in the Autumn.

We followed Ernie Wrights methodology

My son who is an A-level student wrote a short computer program which scale plated all the images and came up with averages. A Mayes Creative intern from Exeter University made all the calculations with guidance from myself. 

If you have enjoyed this maybe you would like to check out the following which Jay Pasachoff kindly shared with me

Pasachoff, Jay M., Bernd Gährken, and Glenn Schneider, 2017, “Using the 2016 transit of Mercury to find the distance to the Sun,” The Physics Teacher 55, 3 (March), 137-141: cover illustration plus article:

Alan Stern et al., New Horizons team, from beyond Pluto:


Udo Backhaus, Germany, from the 2019 transit of Mercury:


thank you everyone for your interest and taking part.

Best wishes