Equatorially Trapped Plasmas - Dynamics Explorer 1
The famous rabbit ears distribution of plasmas:
Plasma Observations at the Earth's Magnetic Equator (pretty much as published in JGR)
Plasma Observations at the Earth's Magnetic Equator (2 of the figures replaced with prettier color versions we left out of the original publication)
There was not much doubt about the trapped plasmas. There was some question about my inference of latitudinal density structures, though the theories seemed to support the idea. Recent work from the IMAGE satellite makes me wonder if the structures I observed could possibly have been due to the radial/local time structures seen on that satellite. Dave Young (politely) suggested that I ought to have been more open to that suggestion.
One of my more data heavy papers, and a tribute to what could be done with the very early internet, a MicroVax II, IDL, and an HP PaintJet printer with nearly fluorescent colors.