--- title: "Voyager 1 passed Saturn 46 years ago on November 12; on November 18 it reaches one light-day from Earth" url: https://badiyaa.com/voyager-1-saturn-flyby-one-light-day/ published: 2026-11-10T22:23:00+00:00 modified: 2026-11-10T22:23:00+00:00 section: Science publisher: Badiyaa --- # Voyager 1 passed Saturn 46 years ago on November 12; on November 18 it reaches one light-day from Earth Voyager 1 flew past Saturn on November 12, 1980, and on November 18, 2026, it will be one light-day, about 16.1 billion miles, from Earth. Voyager 1 skimmed past Saturn on November 12, 1980, passing about 124,000 kilometers (77,000 miles) above the planet’s cloud tops. Forty-six years later, the same probe is days away from a new mark: on November 18, 2026, it will be one light-day from Earth, according to [NASA’s November sky notes](https://science.nasa.gov/solar-system/skywatching/night-sky-network/novembers-night-sky-notes-light-day-away/). That means a radio command sent from the ground will need a full 24 hours to reach it. In 1980 the delay was roughly 85 minutes. ## What the Saturn pass found NASA started its Saturn observation phase on August 22, 1980. The busiest hours came on November 12 and 13, when the probe swung past Titan, Tethys, Saturn itself, Mimas, Enceladus, Rhea and Hyperion in about a day and a half, as the [mission timeline](https://en.wikipedia.org/wiki/Voyager_1) records. Its cameras picked out complex structure in the rings, including the narrow F Ring, which looked twisted and braided. Instruments measured how much helium sits in Saturn’s upper atmosphere: about 7% by volume, against 11% for Jupiter. That shortfall hinted that heavier helium may be sinking slowly through the hydrogen, which could explain why Saturn radiates more heat than sunlight alone delivers. The probe clocked equatorial winds near 500 meters per second, about 1,100 mph, and timed a Saturn day at 10 hours, 39 minutes and 24 seconds. ## The Titan gamble Mission planners shaped the whole route around one moon. Titan, Saturn’s largest, was known to have an atmosphere, and images from Pioneer 11 in 1979 suggested it was thick and complicated. Voyager 1 came within 6,490 kilometers of it. The haze hid the surface completely. Still, measurements of the gas mix, warmth and pressure were enough for researchers to float the idea of liquid hydrocarbon lakes hidden underneath. The price was steep. The Titan-friendly path bent the probe under Saturn’s south pole and out of the plane where the planets orbit, so Voyager 1 could never visit another world. Had that pass failed, Voyager 2 would have been sent to Titan instead, giving up its later visits to Uranus and Neptune. ## How far is one light-day? Light covers 299,792 kilometers every second. Multiply by the 86,400 seconds in a day and the answer is about 25.9 billion kilometers, or 16.1 billion miles. NASA’s Canberra antenna had Voyager 1 at 25.80 billion kilometers when the agency’s late-October note was written, so the final stretch is roughly 100 million kilometers. For comparison, the 1980 flyby happened about 1.5 billion kilometers from our star. The probe is now more than 17 times farther out. ## Timeline from Saturn to the light-day mark - September 5, 1977: launch on a Titan IIIE rocket from Cape Canaveral. - March 5, 1979: closest approach to Jupiter. - November 12, 1980: Titan and Saturn flyby. - February 14, 1990: final images for the Solar System Family Portrait. - August 25, 2012: crosses the heliopause into interstellar space. - April 17, 2026: the Low-Energy Charged Particles instrument is switched off to save power, leaving two instruments working. - November 18, 2026: one light-day from Earth. ## Limits The light-day figure is a distance, not a time on board; the date can shift slightly depending on whether it is measured from Earth or from our star, and the agency’s note gives the mark as 16.1 billion miles from the solar center. Several of the 1980 results, such as the Titan lakes, were only speculation until later missions returned to Saturn. Voyager 1 is not the only distant traveler on our radar; Badiyaa recently looked at [why Uranus spins tipped over at nearly 98 degrees](https://badiyaa.com/uranus-tilt-98-degrees-seasons-collision/), a world only Voyager 2 has visited, and at [NASA’s $10 billion plan for Moon Base cargo landers](https://badiyaa.com/nasa-10-billion-moon-base-landers-clps-2/). More stories sit on our [Science page](https://badiyaa.com/category/science/). The next date to watch is November 18, when the signal gap reaches a full day. ## Further reading - [Wikipedia: Voyager 1](https://en.wikipedia.org/wiki/Voyager_1) - [NASA: November’s Night Sky Notes: Light-Day Away](https://science.nasa.gov/solar-system/skywatching/night-sky-network/novembers-night-sky-notes-light-day-away/) *Image: NASA, Public domain via Wikimedia Commons* *This article was produced with AI assistance and reviewed by our Editorial Desk. [How we work](https://badiyaa.com/editorial-policy/).*