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

Detailed summary

Launched in 1977, the spacecraft and its twin have visited planets, captured images, and kept sailing.

Launched in 1977, the spacecraft and its twin have visited planets, captured images, and kept sailing.

NASA's Voyager 1 is about to become humanity's first object to reach one light-day from Earth as it pushes ever deeper into interstellar space.

That's a mind-blowing distance of more than 16 billion miles (26 billion kilometers) for the spacecraft launched 49 years ago.

When Voyager 1 reaches that remarkable milestone on Wednesday, its radio signals will take precisely 24 hours traveling at the speed of light to reach Earth — in other words, one light-day. NASA is looking at another 18,000 years before the spacecraft achieves a full light-year and more than double that before it comes near another star.

Project manager Suzanne Dodd sees Voyager 1 as Earth's ambassador hurtling between stars while providing a "sense of wonder" on the home front.

"It's a national treasure," she told The Associated Press. "Really extraordinary."

To celebrate this moment, NASA is urging people from all corners to grab their phone or a flashlight to create a wave of golden light after sunset Tuesday, using Morse code to spell the letters V-G-R, Voyager's call sign, into the night sky.

Despite sporadic problems typical of old age, Voyager 1 and its twin Voyager 2 continue to send back science and engineering data as they zoom toward different points in space at 38,000 mph (61,000 kph). Although launched two weeks before its sibling in 1977, Voyager 2 won't reach the one light-day mark until 2035.

Voyager 1 swept past Jupiter and Saturn to scientists' delight in 1979 and 1980, respectively, before exiting the solar system. It reached what NASA defines as interstellar space — the expansive region between star systems — in 2012. Voyager 2 visited those two planets plus Uranus and Neptune, also sending back stunning photos, before entering interstellar space in 2018.

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