Voyager 1 Is About to Be a Full Light-Day From the Sun, on Nov. 18

NASA says that on Nov. 18, 2026, Voyager 1 will pass a new distance milestone: one light-day from the Sun, at 16.1 billion miles. The date falls 49 years after the spacecraft’s launch, according to the agency’s November Night Sky Notes.

The note describes a light-day as a measure of distance, not of time, and uses the milestone to explain how astronomers describe the huge gaps between objects in space.

How far away is Voyager 1 right now?

NASA tracks both Voyager probes with its Deep Space Network. When the Night Sky Notes article was written, the Canberra antenna was following Voyager 1 at 25.80 billion km, or just over 16 billion miles. That is only a little short of the line the spacecraft is due to cross next month.

What are the Voyagers, and how did they get here?

NASA launched the twin spacecraft Voyager 1 and Voyager 2 in 1977. The launches took advantage of an alignment of the four largest planets in the solar system, Jupiter, Saturn, Uranus and Neptune, that comes around once every 175 years. By using six gravity assists between those planets, the mission, known as the Grand Tour, gave scientists up-close views of the gas and ice giants and several of their moons.

By the 1980s the two probes parted ways at Saturn. Voyager 2 went on toward Uranus and Neptune. Voyager 1 took one more portrait of the solar system, leaving out Mercury and Mars, including a last image of Earth, the pale blue dot.

Did the probes already leave the solar system’s edge?

Both crossed the heliopause, the boundary where the Sun’s solar wind meets the interstellar medium. Voyager 1 did so in August 2012 and Voyager 2 in November 2018. The coming light-day mark is a separate milestone, measured in distance from the Sun.

What is on the Golden Record?

Each spacecraft carries a Golden Record, a 12-inch phonograph record meant as a message from Earth. According to NASA, it holds:

• spoken greetings in 55 languages;
• 27 musical tracks;
• 116 images;
• other sounds from Earth.

The record’s protective cover carries etchings that show the Sun’s location relative to 14 pulsars, along with instructions for playing it. The designers used various metals to shield the encoded information from space radiation. The record is copper with gold plating, and the cover is aluminum. NASA says the cover was electroplated with an ultra-pure sample of uranium-238, an isotope with a half-life of 4.468 billion years.

Why it matters: what does a light-day tell readers?

For most people, the Voyager milestone is a chance to picture just how big space is. NASA’s note points out that readers may know the term light-year from science fiction or stargazing, and it recommends a video that compares the inner solar system, the outer solar system and the space beyond using light-based measures. A figure like 16.1 billion miles is hard to imagine, and a unit tied to light gives it a handy scale.

The agency also offers hands-on material for families and classrooms. A Gravity Assist activity lets people get a feel for how the maneuver works, and an activity guide called Measuring a Kid Minute explores what it means to measure a light-minute. NASA also provides a way to track each Voyager spacecraft online.

What happens next?

The next date to watch is Nov. 18, 2026, when Voyager 1 is expected to reach the one-light-day mark. NASA’s Deep Space Network will keep tracking both probes as they travel on, with the agency’s Canberra antenna following Voyager 1 at the time of the article.

Around Prague, based on reporting by NASA