Magnetic Fields at Neptune

• DOI: 10.1126/science.246.4936.1473
• Publication Date: 2006-10-05T21:21:28Z
• Authors: Norman F. Ness; Mario H. Acuña; Leonard F. Burlaga; John E. P. Connerney; Ronald P. Lepping; Fritz M. Neubauer
• Keywords: Neptune; Mercury's magnetic field; Magnetosphere of Saturn; Field line

The National Aeronautics and Space Administration Goddard Flight Center-University of Delaware Bartol Research Institute magnetic field experiment on the Voyager 2 spacecraft discovered a strong complex intrinsic Neptune an associated magnetosphere tail. detached bow shock wave in supersonic solar wind flow was detected upstream at 34.9 radii (R(N)), magnetopause boundary tentatively identified 26.5 R(N) near planet-sun line (1 = 24,765 kilometers). A maximum nearly 10,000 nanoteslas nanotesla 10(-5) gauss) observed closest approach, distance 1.18 R(N). planetary between 4 15 can be well represented by offset tilted dipole (OTD), displaced from center surprisingly large amount 0.55 inclined 47 degrees with respect to rotation axis. OTD moment is 0.133 gauss-R(N)(3). Within R(N), representation must include localized sources or higher order multipoles, both, which are not yet determined. obliquity phase its encounter combined serendipitously so that entered time when polar cusp region directed almost precisely sunward. As exited magnetosphere, tail appeared monopolar, no crossings imbedded reversal plasma neutral sheet were observed. auroral zones most likely located far poles may have complicated geometry. rings all known moons deep inside except for Nereid, outside sunward planet. radiation belts will structure owing absorption energetic particles losses significant changes diurnally varying configuration. In astrophysical context, Neptune, like Uranus, described as "oblique" rotator.