Voyager 1 approaches a day of light-travel time from Earth
Voyager 1 is expected to reach a distance of one light-day from Earth on November 18. NASA has announced public events to mark the approaching milestone, including a symbolic light display and a discussion with the mission team. The spacecraft continues to send scientific observations from interstellar space, decades after its 1977 launch.
Science··Morning
A signal takes a full day
Voyager 1 is approaching a distance at which light from Earth will need an entire day to reach it.[1], [2]
The US space agency NASA announced on November 10 that the spacecraft is expected to cross that threshold on November 18, at about 25.9 billion kilometres. The announcement therefore concerns an approaching milestone. Voyager 1 has not yet reached that distance. Popular Science also reported the planned public celebrations and the crossing. The probe, launched in 1977, remains the most distant object built by people. Its continuing journey now gives a familiar unit of time a striking spatial meaning: even a signal travelling at light speed will spend twenty-four hours on the outward trip.[1]
Public celebrations precede the crossing
A symbolic light activity is scheduled for after sunset on November 17. Phones and tablets will flash VGR, the spacecraft’s call sign, in Morse code. NASA has invited public participation in the celebration; the flashes are a commemorative display rather than an attempt to communicate with the spacecraft. A separate discussion will take place on November 19 at noon Eastern Standard Time at NASA’s Jet Propulsion Laboratory, the centre that manages Voyager. Mission staff and agency leaders will discuss the probes’ condition, measurements from interstellar space and the practical challenges of operating spacecraft for so many decades. The programme also provides time for questions from journalists and other audience members.[1]
Voyager keeps measuring beyond the Sun’s bubble
Voyager 1 entered interstellar space in 2012, while Voyager 2 crossed on another trajectory in 2018. Both continue transmitting observations beyond the heliosphere, the protective region shaped by the Sun. NASA’s Deep Space Network maintains communications. The mission was designed to take advantage of an outer-planet alignment that occurs roughly every 176 years. The November discussion will be held in the von Kármán Auditorium, which hosted briefings during Voyager’s planetary encounters. Participants include project manager Suzanne Dodd and deputy project scientist Jamie Rankin. A documentary preview is also planned ahead of the mission’s fiftieth anniversary in 2027. The light-day crossing marks distance travelled, while the spacecraft’s science concerns the environment it continues to encounter.[1]
