NASA's Voyager 1 closes in on a light-day in interstellar space for a new distance record

NASA's Voyager 1 spacecraft is on the verge of reaching a remarkable milestone: one light-day from Earth. This extraordinary distance of over 16 billion miles (26 billion kilometers) is the furthest any human-made object has ever traveled. Launched 49 years ago, Voyager 1 continues to beam back scientific data despite its age and occasional communication issues.

When the spacecraft attains this milestone on Wednesday, its radio signals will take exactly 24 hours, or one light-day, to reach Earth, given the immense distance separating the two. Project manager Suzanne Dodd describes Voyager 1 as Earth's ambassador navigating the interstellar space and inspiring wonder back home. To mark this momentous occasion, NASA is encouraging people to create a golden light wave using Morse code spelling out "V-G-R" from their phones or flashlights after sunset Tuesday.

While Voyager 1 overtook Jupiter and Saturn in 1979 and 1980 respectively, Voyager 2, its twin launched two weeks earlier, will not reach this one-light-day point until 2035. Both spacecraft have been diligently sending data about their uncharted interstellar environment—magnetic fields, pressure, dust, and galactic cosmic rays—since 2012. The skeleton flight control team at NASA's Jet Propulsion Laboratory in California manages the spacecraft's operations, with assistance from retired engineers when needed.