AWhat changed
Bertotti, Iess and Tortora analyzed multifrequency radio signals sent to and from the Cassini spacecraft near the Sun. Their 2003 fit reported the post-Newtonian parameter γ = 1 + (2.1 ± 2.3) × 10⁻⁵, consistent with the general-relativistic value within the reported uncertainty.
Scientific scope
Bertotti, Iess and Tortora analyzed multifrequency radio signals sent to and from the Cassini spacecraft near the Sun. Their 2003 fit reported the post-Newtonian parameter γ = 1 + (2.1 ± 2.3) × 10⁻⁵, consistent with the general-relativistic value within the reported uncertainty. The result is inferred from a model of the radio-frequency shift, spacecraft orbit, propagation and nongravitational forces. It is a test in the stated solar-system setting, not proof of every aspect of general relativity. The three paper authors and the wider teams that enabled the spacecraft and radio systems have distinct roles. The paper credits mission and tracking personnel separately; an overlapping 2003 conference report must not be automatically scored as an independent observation.
Evidence
The linked original works support the scoped statement and contribution attribution. WRS has not independently replayed experiments or reconstructed a full mathematical proof. The result is inferred from a model of the radio-frequency shift, spacecraft orbit, propagation and nongravitational forces. It is a test in the stated solar-system setting, not proof of every aspect of general relativity. The three paper authors and the wider teams that enabled the spacecraft and radio systems have distinct roles. The paper credits mission and tracking personnel separately; an overlapping 2003 conference report must not be automatically scored as an independent observation.
Contributors
- The named authors in the research record · SCIENCE: These are the source-listed authors of this specific paper. Individual effort, author nationality and unresolved cross-record identities are not inferred.
Provisional WRS assessment, edition 2026-10-27.3. Independent expert calibration is pending. This grade does not certify correctness or assign ownership.
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