Graph of the One-Way Light-Travel Times for the Voyager 1 and 2 spacecraft over the year 2024. It shows a wavy line that increases as time goes on, but with minima in the first half of the year.

Notices where this attachment appears

1. Embed this notice
   NSFVoyager2 (nsfvoyager2@techhub.social)'s status on Wednesday, 01-Jan-2025 02:20:50 JST NSFVoyager2

   1/ On this last day of 2024, I thought this might interest those of you following our progress in detail. Here is a summary of all the One-Way Light Travel Times of the Voyager spacecraft over 2024.

   The first thing to note is that the plot lines have different vertical axes! While the times are _offset_, the scale is the same. If you plot both these times on a single vertical scale, you can barely see the sinusoidal shape. Remember: green with green, blue with blue.

   OK, why is there this shape? Because the distance measurements are being made from a moving platform: Earth. The sinusoidal variance is because of Earth's orbit around the Sun. At certain times of year, the Earth is actually moving towards the Voyagers faster than they are leaving, so the distance _decreases_.

   Continues...