The Long Quiet Goodbye of Pioneer 10: Heat, Time, and a Silent Voyager

Pioneer 10, launched in 1972, sent its last faint signal in January 2003 from about 12 billion kilometres away as its power from plutonium-238 RTGs faded; the eleven-hour transmission highlighted a graceful end to a 30-year mission, later explained as heat radiation affecting the craft’s trajectory rather than new physics, and the probe remains a silent, drifting artifact with a gold plaque honoring human exploration.