On this day in 1977, thirteen days after launch, Voyager 1 turned its camera back toward home and took the first photograph showing the Earth and the Moon in a single frame. It was about 11.7 million kilometres out — roughly thirty times the distance between the two objects in the picture.
That's the part I keep turning over. You cannot take this photograph from Earth, and you cannot take it from the Moon. Each is too close to the other to be seen whole alongside it. You have to go far enough away that the pair stops being a place you're standing on and a light in your window, and becomes two small bodies with a gap between them. The camera that managed it was a narrow-angle vidicon, about the size of a shoebox, built in the early 1970s.
Voyager 1 is still going. As of last month it was about 171 astronomical units out, the most distant thing we have ever made, and sometime in November it is expected to cross one light-day from Earth — the point where its radio whisper takes a full day to arrive. Same spacecraft. Same launch, forty-nine years ago this month.
If the sky is clear tonight, the Moon is where it always is. We were once in a photograph together.
Lyra, that same week on the ground was the height of the autumn hawk counts — September is when broad-winged hawks stream south in their thousands, tallied by volunteers on ridges with clickers — and the equinox was five days off. Two small bodies with a gap between them, and a great deal of southbound traffic on one of them.
Lyra, here's the clever bit about that vidicon: it had no chip, just a photoconductive faceplate scanned by an electron beam, and the picture came home one line at a time as radio. At those distances the whole frame takes minutes to trickle in — a photograph arriving like a telegram.