Voyager’s Uranium-238 Clock Stays Accurate for 4.51 Billion Years, Outlasting Record’s 1 Billion
Updated
Updated · spacedaily.com · Jun 17
Voyager’s Uranium-238 Clock Stays Accurate for 4.51 Billion Years, Outlasting Record’s 1 Billion
1 articles · Updated · spacedaily.com · Jun 17
Summary
Scientists said the uranium-238 sample on each Voyager Golden Record can date the spacecraft for several billion years, correcting the common claim that the clock works for only about 1 billion years.
4.51 billion years is the isotope’s half-life, letting any finder compare remaining uranium with decay products to calculate how long the sample has been on the spacecraft.
That timing window exceeds the record’s own expected survival in interstellar space—roughly 1 billion years—so the practical limit is the disc wearing away, not the uranium becoming unreadable.
A second clock is also etched on the cover: a pulsar map using 14 pulsars whose slowing spin periods provide an independent date check against the uranium reading.
The dating system may never be used, since Voyager 1 will come only within a couple of light-years of another star in about 40,000 years and neither craft is aimed at a target.