on-this-day · september 5
artist's concept of the voyager spacecraft. source: wikimedia commons
The Message in a Bottle We Threw at the Stars
On this day in 1977 — Voyager 1 launched. It's now the farthest human-made object from Earth, still transmitting.
2 min read
On September 5, 1977, a Titan IIIE rocket lifted off from Cape Canaveral carrying Voyager 1. Its mission: fly by Jupiter and Saturn, send back data, then keep going. Designed to last five years. Nearly five decades later, it is still operating, over 15 billion miles from Earth, moving through interstellar space at 38,000 miles per hour. The farthest human-made object from our planet.
Voyager 1 was built during a planetary alignment that happens once every 176 years -- gravity assists would slingshot it from planet to planet. The computers ran on 69 kilobytes of memory. Power came from decaying plutonium-238. Everything was designed for longevity and the assumption that no one would ever repair it.
It reached Jupiter in March 1979, discovering active volcanoes on Io. At Saturn in November 1980, it photographed the rings in unprecedented detail. Then it headed upward, out of the solar system's plane.
On February 14, 1990, at Carl Sagan's request, Voyager turned its camera back toward Earth. From 3.7 billion miles away, it captured our planet as a pale blue dot, smaller than a single pixel. Sagan called it a reminder of our fragility and the preciousness of the only home we have ever known. The last photograph Voyager ever took.
the pale blue dot — earth photographed by voyager 1 from 3.7 billion miles away, february 14, 1990. source: wikimedia commons
In August 2012, Voyager 1 crossed the heliopause into interstellar space. Mounted to its side is a golden record -- sounds and images of life on Earth, greetings in 55 languages, music from Bach to Chuck Berry. Long after humanity is gone, Voyager will still be out there, carrying our music into the dark. The longest message we have ever sent.