Scientists Resolve Pioneer Anomaly, Tracing 8.74 x 10⁻¹⁰ m/s² Deceleration to Waste Heat
Updated
Updated · spacedaily.com · May 21
Scientists Resolve Pioneer Anomaly, Tracing 8.74 x 10⁻¹⁰ m/s² Deceleration to Waste Heat
1 articles · Updated · spacedaily.com · May 21
Slava Turyshev’s team showed Pioneer 10 and 11’s unexplained sunward deceleration was caused by thermal recoil, not new physics, resolving a puzzle that lingered for about 30 years.
About 2,500 watts from the probes’ plutonium power sources radiated unevenly: heat reflected off the back of the high-gain antenna and leaked from electronics, producing a tiny backward push toward the Sun.
Recovered Doppler records and telemetry from old magnetic tapes let researchers build fuller thermal models, which made the anomaly disappear and showed it was slowly fading with plutonium-238 decay.
The effect—8.74 x 10⁻¹⁰ metres per second squared, roughly a ten-billionth of Earth’s gravity—still left the probes thousands of kilometres closer to Earth each year than earlier equations predicted.
The result preserved Newtonian gravity and general relativity, ending speculation that the Pioneers had exposed exotic cosmology while underscoring how archival data and spacecraft engineering can settle fundamental questions.
With the Pioneer anomaly solved, which other spaceflight mysteries could still rewrite the laws of physics?
If heat solved the Pioneer anomaly, why are new theories for this deep space mystery still being proposed?
How does a decades-old space mystery now influence the design of NASA's future deep space missions?