Unanswered Questions for Johnston Archive

[7yl4r]

Some questions I came away with from Johnston Archive article "Reading the Pioneer/Voyager Pulsar Map"

1. Pulsar distances and angles from galactic center as indicated on the map and as measured more recently are quite different in some cases. Is this because we have more accurately measured the values, or are pulsars really zipping around that quickly? Put another way, how much uncertainty is there in the measurements included on the original map?

2. I believe the pulsar map represents distance from Earth as well as the z-coordinate perpendicular to the galactic plane. How is this done exactly? Does the line represent true distance with z-coordinate marked from the end, or is the line a projection of the distance vector onto the galactic plane with the z-coordinate then added to the end of the line?

I sent an email to [email protected] in 2014 July but never got a response.