Science. 1989 Dec 15;246(4936):1494-8. doi: 10.1126/science.246.4936.1494.
The Voyager 2 plasma wave instrument detected many familiar plasma waves during the encounter with Neptune, including electron plasma oscillations in the solar wind upstream of the bow shock, electrostatic turbulence at the bow shock, and chorus, hiss, electron cyclotron waves, and upper hybrid resonance waves in the inner magnetosphere. Low-frequency radio emissions, believed to be generated by mode conversion from the upper hybrid resonance emissions, were also observed propagating outward in a disklike beam along the magnetic equatorial plane. At the two ring plane crossings many small micrometer-sized dust particles were detected striking the spacecraft. The maximum impact rates were about 280 impacts per second at the inbound ring plane crossing, and about 110 impacts per second at the outbound ring plane crossing. Most of the particles are concentrated in a dense disk, about 1000 kilometers thick, centered on the equatorial plane. However, a broader, more tenuous distribution also extends many tens of thousands of kilometers from the equatorial plane, including over the northern polar region.
航海者 2 号等离子波仪器在与海王星相遇时探测到了许多熟悉的等离子波，包括太阳风中弓形激波上游的电子等离子体振荡、弓形激波处的静电湍流以及内磁层中的哨声、啸声、电子回旋波和上混合共振波。还观察到向外传播的低频无线电发射，据信是由上混合共振发射的模式转换产生的，它们沿着磁赤道平面以盘状波束向外传播。在两次环面交叉处，许多微小的微米级尘埃颗粒被探测到撞击航天器。最大的撞击率约为每秒钟 280 次，在入境环面交叉处，每秒钟约 110 次。大多数粒子集中在一个厚约 1000 公里、以赤道平面为中心的密集盘中。然而，一个更宽、更稀疏的分布也从赤道平面向外延伸了数万公里，包括北极地区。
