Picture sending a text and waiting a full day for it to arrive. That is the everyday reality of talking to Voyager 1, launched by NASA in 1977 and still sending data home.
On Wednesday, Nov. 18, 2026, at 5:16:07 a.m. EST, the probe reaches a distance NASA describes as one light-day from Earth. No other human-made object has ever gotten there.
NASA puts a light-day at 16,094,799,096 miles, or 25,902,068,356 kilometers. Science News notes that is more than four times the distance from the sun to Pluto.
Radio waves travel at light speed, so a command from Earth now needs a full day to reach the spacecraft. Any reply takes another day to come back, making a simple round trip 48 hours.
By the time Voyager 1 hits the mark, it will have been traveling for 49 years, two months, and 11 days. NASA calls it a mile marker reached by no other human-made object.
Oddly, the probe won't notice a thing. ScienceDaily points out that crossing the line changes nothing physically, since the milestone is a human-made marker, not an event the spacecraft experiences.
The next stretch is the hard part. NASA reportedly expects the Deep Space Network to lose contact around 2036, long before Voyager 1 reaches two light-days away.
