{"copyright":{"thirdPartyPermissionsProduced":false,"disclosedToPublic":false,"containsIndication":false,"publisherPermissionOrRightsToDistribute":false,"belongsToUsGov":false,"determinationType":"GOV_PUBLIC_USE_PERMITTED","thirdPartyContentCondition":"NOT_SET","belongsToContractor":false,"disclosedInvention":false,"submissionId":19850003642,"containsThirdPartyMaterial":false,"belongsToPublisher":false,"id":"ed7d545b493b49af80c6365a6f25c5d6","belongsToAuthors":false},"subjectCategories":["Solar Physics"],"exportControl":{"isExportControl":"NO","submissionId":19850003642,"ear":"NO","id":"0d8be40c96a54d8495986829a71cc3f9","itar":"NO"},"distributionDate":"2014-09-12T10:35:31.4370000+00:00","title":"The Solar Wind at 20-30 AU","stiType":"CONFERENCE_PAPER","distribution":"PUBLIC","submittedDate":"2013-08-12T13:23:00.0000000+00:00","authorAffiliations":[{"sequence":0,"submissionId":19850003642,"meta":{"author":{"name":"Barnes, A."},"organization":{"name":"NASA Ames Research Center","location":"Moffett Field, CA, United States"}},"id":"31877ebb1f0a4722b7a74a06849ef28b"},{"sequence":1,"submissionId":19850003642,"meta":{"author":{"name":"Gazis, P. R."},"organization":{"name":"NASA Ames Research Center","location":"Moffett Field, CA, United States"}},"id":"7de559106083443ba213a5c8043f6d51"}],"stiTypeDetails":"Conference Paper","technicalReviewType":"TECHNICAL_REVIEW_TYPE_NONE","modified":"2025-08-31T18:39:21.7150190+00:00","id":19850003642,"legacyMeta":{"__type":"LegacyMetaIndex, StrivesApi.ServiceModel","accessionNumber":"85N11950"},"created":"2013-08-12T13:23:00.0000000+00:00","center":{"code":"CDMS","name":"Legacy CDMS","id":"092d6e0881874968859b972d39a888dc"},"onlyAbstract":false,"sensitiveInformation":2,"abstract":"Pioneer 10 sampled the interplanetary plasma over the range 20 to 30 astronomical units, during the period 1979-1983. The median flow speed is about 400 km/s, and at 20 AU the median density, proton temperature and dynamic pressure are, respectively, 0.025 cm-3, 10(4) K, and 6x10-11 dyne cm-2. It is shown that the average solar wind flow speed does not vary significantly with increasing heliocentric distance, and the density falls off as R-2, as predicted by simple solar wind models. The day-to-day variations in solar wind parameters are smaller at larger distance. Very large shocks however, were detected beyond 25 AU. Comparison of Pioneer 10 and 11 observations at similar distances but different phases of the solar activity cycle shows that solar wind dynamic pressure varies over a wider range during epochs of high solar activity. The variation near 20 AU is likely to be smaller at Voyager 2 Uranus encounter than observed by Pioneer 10 in the 1979-80 period.","isLessonsLearned":false,"disseminated":"METADATA_ONLY","publications":[{"submissionId":19850003642,"id":"15f374926a974e198b496c1d15d1a103","publicationName":"JPL  Uranus and Neptune","publicationDate":"1984-10-01T00:00:00.0000000+00:00"}],"status":"CURATED","related":[{"disseminated":"DOCUMENT_AND_METADATA","id":19850003619,"type":"ANALYTIC_PRIMARY","title":"Uranus and Neptune","stiType":"CONFERENCE_PROCEEDINGS","distribution":"PUBLIC","status":"CURATED"},{"disseminated":"DOCUMENT_AND_METADATA","id":19850003619,"type":"ANALYTIC_PRIMARY","title":"Uranus and Neptune","stiType":"CONFERENCE_PROCEEDINGS","distribution":"PUBLIC","accessionNumber":"N85-11928 through N85-11956","status":"CURATED"}],"downloads":[],"downloadsAvailable":true,"index":"submissions-2026-06-04-04-53"}