The heavily instrumented Convair 990 jet had been used to study targets from Comet Kohoutek to terrestrial monsoons since the agency acquired it in 1973, and had photographed
AMPTE's first artificial comet in December.
One problem for the AMPTE researchers trying to decide whether to go ahead with the barium release was that they could not know in advance about the condition of the interplanetary magnetic field that transports the solar-wind particles that ultimately populate earth's magnetic tail.
"I think," he says of the earth's-tail version, "that nobody has ever seen such a thing," suggesting that AMPTE's data could aid studies of the solar corona and photosphere.