{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T22:40:15Z","timestamp":1791499215230,"version":"4.3.4"},"reference-count":13,"publisher":"American Association for the Advancement of Science (AAAS)","issue":"5286","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Science"],"published-print":{"date-parts":[[1996,10,18]]},"abstract":"<jats:p>\n            Plasma measurements made during the flyby of Io on 7 December 1995 with the Galileo spacecraft plasma analyzers reveal that the spacecraft unexpectedly passed directly through the ionosphere of Io. The ionosphere is identified by a dense plasma that is at rest with respect to Io. This plasma is cool relative to those encountered outside the ionosphere. The composition of the ionospheric plasmas includes O\n            <jats:sup>++<\/jats:sup>\n            , O\n            <jats:sup>+<\/jats:sup>\n            and S\n            <jats:sup>++<\/jats:sup>\n            , S\n            <jats:sup>+<\/jats:sup>\n            , and SO\n            <jats:sub>2<\/jats:sub>\n            <jats:sup>+<\/jats:sup>\n            ions. The plasma conditions at Io appear to account for the decrease in the magnetic field, without the need to assume that Io has a magnetized interior.\n          <\/jats:p>","DOI":"10.1126\/science.274.5286.394","type":"journal-article","created":{"date-parts":[[2002,7,27]],"date-time":"2002-07-27T09:37:46Z","timestamp":1027762666000},"page":"394-395","source":"Crossref","is-referenced-by-count":187,"title":["Plasma Observations at Io with the Galileo Spacecraft"],"prefix":"10.1126","volume":"274","author":[{"given":"L. A.","family":"Frank","sequence":"first","affiliation":[{"name":"L. A. Frank, W. R. Paterson, K. L. Ackerson, Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"W. R.","family":"Paterson","sequence":"additional","affiliation":[{"name":"L. A. Frank, W. R. Paterson, K. L. Ackerson, Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K. L.","family":"Ackerson","sequence":"additional","affiliation":[{"name":"L. A. Frank, W. R. Paterson, K. L. Ackerson, Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"V. M.","family":"Vasyliunas","sequence":"additional","affiliation":[{"name":"V. M. Vasyliunas, Max Planck Institut f\u00fcr Aeronomie, Katlenburg-Lindau, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"F. V.","family":"Coroniti","sequence":"additional","affiliation":[{"name":"F. V. Coroniti, Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S. J.","family":"Bolton","sequence":"additional","affiliation":[{"name":"S. J. Bolton, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"221","reference":[{"key":"e_1_3_1_2_2","doi-asserted-by":"crossref","first-page":"935","DOI":"10.1038\/217935a0","volume":"217","author":"Piddington J. H.","year":"1968","unstructured":"Piddington J. H., Drake J. F., Nature 217, 935 (1968);","journal-title":"Nature"},{"key":"e_1_3_1_2_3","doi-asserted-by":"publisher","DOI":"10.1086\/149947"},{"key":"e_1_3_1_2_4","first-page":"525","volume":"175","author":"Gurnett D. A.","year":"1972","unstructured":"Gurnett D. A., ibid. 175, 525 (1972);","journal-title":"ibid."},{"key":"e_1_3_1_2_5","first-page":"664","volume":"227","author":"Dessler A. J.","year":"1979","unstructured":"Dessler A. J., Hill T. W., ibid. 227, 664 (1979).","journal-title":"ibid."},{"key":"e_1_3_1_3_2","doi-asserted-by":"crossref","first-page":"1008","DOI":"10.1038\/2031008a0","volume":"203","author":"Bigg E. K.","year":"1964","unstructured":"Bigg E. K., Nature 203, 1008 (1964).","journal-title":"Nature"},{"key":"e_1_3_1_4_2","doi-asserted-by":"crossref","first-page":"527","DOI":"10.1007\/978-94-010-2206-4_47","volume-title":"Exploration of the Planetary System","author":"Brown R. A.","year":"1974","unstructured":"Brown R. A., in Exploration of the Planetary System, , Woszczyk A., Iwaniszewska C., Eds. (Reidel, Dordrecht, Netherlands, 1974), pp. 527\u2013531"},{"key":"e_1_3_1_5_2","doi-asserted-by":"crossref","first-page":"L51","DOI":"10.1086\/182088","volume":"205","author":"Kupo I.","year":"1976","unstructured":"Kupo I., Mekler Y., Eviatar A., Astrophys. J. Lett. 205, L51 (1976).","journal-title":"Astrophys. J. Lett."},{"key":"e_1_3_1_6_2","doi-asserted-by":"publisher","DOI":"10.1029\/JA085iA03p01171"},{"key":"e_1_3_1_6_3","unstructured":"Southwood D. J. Kivelson M. G. Walker R. J. Slavin J. A. ibid. p. 5959."},{"key":"e_1_3_1_7_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.204.4396.982"},{"key":"e_1_3_1_8_2","unstructured":"Morabito L. A. Synnott S. P. Kupferman P. N. Collins S. A. ibid. p. 972."},{"key":"e_1_3_1_9_2","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1007\/BF00216858","volume":"60","author":"Frank L. A.","year":"1992","unstructured":"Frank L. A., Ackerson K. L., Lee J. A., English M. R., Pickett G. L., Space Sci. Rev. 60, 283 (1992). The plasma analyzer consists of a set of nested spherical-segment plates supplied with a programmed series of voltages that provide energy-per-unit charge (E\/Q) analyses of positive ions and electrons, separately and simultaneously. Multiple sensors at the exit apertures of these electrostatic analyzers allow determination of the latitude of the direction of arrival of the charged particles with respect to the spacecraft axis. The rotation about the spacecraft axis allows the analyzers to sample the full range of azimuths for the arriving particle trajectories. Thus, all directions of arrival for the charged particles are covered. Typically, the number of directions for arrival is programmed to be 56. For each direction of arrival E\/Q, samples at 32 to 64 logarithmically spaced values are taken in the E\/Q range from 0.9 V to 52 kV. In addition, three miniature magnetic spectrometers are positioned at the exit apertures of the electrostatic analyzers for the positive ions. The angular coverage of these mass spectrometers is three partial ranges of particle arrival latitudes. For a given value of E\/Q, the magnetic fields in the mass spectrometers are varied in order to obtain a mass-per-unit charge (M\/Q) analysis of the composition. O+ and S++ ions, two of the major ions in Io's torus, cannot be identified separately with the plasma instrumentation. The temporal resolution for gaining complete determination of the plasma distributions is limited by the rotation period of the spacecraft platform, about 20 s.","journal-title":"Space Sci. Rev."},{"key":"e_1_3_1_12_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.273.5273.337"}],"container-title":["Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.science.org\/doi\/pdf\/10.1126\/science.274.5286.394","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,8,7]],"date-time":"2024-08-07T11:32:44Z","timestamp":1723030364000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.science.org\/doi\/10.1126\/science.274.5286.394"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1996,10,18]]},"references-count":13,"journal-issue":{"issue":"5286","published-print":{"date-parts":[[1996,10,18]]}},"alternative-id":["10.1126\/science.274.5286.394"],"URL":"https:\/\/doi.org\/10.1126\/science.274.5286.394","relation":{},"ISSN":["0036-8075","1095-9203"],"issn-type":[{"value":"0036-8075","type":"print"},{"value":"1095-9203","type":"electronic"}],"subject":[],"published":{"date-parts":[[1996,10,18]]}}}