In 1977, NASA launched the Voyager 1 probe into space to explore the outer reaches of our solar system and beyond. Little did they know that this small spacecraft would become one of the most remarkable and fascinating achievements in human space exploration, able to mark an era in the collective imagination, inspiring future generations.
The right premises
The launch took place as part of the Voyager Program, which involved the construction of two identical probes. Voyager 2 departed a month before its older sister, the Voyager 1 launched on Sep. 5, 1977, from Cape Canaveral, Florida, aboard a Titan III-Centaur rocket.
Its mission regarded the study of Jupiter and Saturn and in particular, the Titan satellite,its magnetic fields and rings, and to photograph the respective natural satellites. But it ended up exploring much more than that.
The probe is about the size of a small car and is equipped with a variety of scientific instruments, all the best possible for those years, including cameras, spectrometers, and plasma detectors, all designed to gather data about the planets it encountered.
At the core of the mission
After its launch, the probe spent the next two and a half years traveling to Jupiter, where it made its first major discovery. The probe passed by the gas giant on March 5, 1979, and continued to photograph the planet until April. A short time later it was the turn of the sister probe Voyager 2.
The two Voyagers made numerous discoveries on Jupiter and its moons. Most surprising was the discovery of sulfur volcanoes on Io, which had never been observed either from Earth or by Pioneer 10 or Pioneer 11 (two previous important missions). After that, it was discovered that Jupiter had a complex system of moons, including the four largest, which are now known as the Galilean moons: Io, Europa, Ganymede, and Callisto.
Voyager 1 also discovered that Jupiter had a powerful magnetic field and intense radiation belts, which posed a risk to any spacecraft that ventured too close.
Next target, next challenges
After completing its mission at Jupiter, the spacecraft continued toward Saturn, where it made even more discoveries. The point of closest approach was reached on Nov. 12, 1980, when it passed just over 120000 km from the planet.
The probe discovered that Saturn had hundreds of rings, each made up of thousands of individual particles, and that it had many more moons than previously thought. Voyager 1 also discovered that Saturn’s moon Titan had an atmosphere, which made it the only moon in the solar system with one.
Captain, the world ends here!
In November 2003 it was announced that, according to the analysis of the recorded data, Voyager 1 would have passed the “termination shock” (the boundary where the particles of the solar wind are slowed down to subsonic speeds), reached in December 2004.
Voyager 1 continued to travel farther and farther away from the sun, eventually leaving our solar system altogether in 2012. At that point, it became the first human-made object to enter interstellar space, the space between stars. It is now more than 22 billion km from Earth, continuing to send data back to scientists, and providing valuable insights into the nature of our universe.
At the edge of the solar system
Data from December 2012 sent by the probe demonstrate new and sensational discoveries of the solar system’s borderline. The spacecraft has entered a “magnetic highway” that connects the solar system to interstellar space.
Another important milestone was reached on Aug. 25, 2012, at about 121 AU from the Sun. Voyager 1 passed the heliopause boundary (the edge at which the solar wind emitted by our Sun is stopped by the interstellar medium.):this was indicated by a new measurement of the plasma density of low-energy particles surrounding the spacecraft.
The traveler’s rest.
One of the most remarkable things about Voyager 1 is that in 2023, the spacecraft has been operating and reporting data for 45 years and it is more than 159.5 AU (24 billion km) from the Sun, making it the farthest man-made object from Earth.
It is expected to continue operating until 2025 when RTGs (A radioisotope thermoelectric generator or RTG is an electrical energy generator based on the decay of radioactive isotopes) will stop in providing enough electricity. Its instruments will continue to gather data about the particles and radiation it encounters as it travels through interstellar space.
An eternal hug
In addition to its scientific discoveries, Voyager 1 also had a profound impact on human culture. In 1989, astronomer Carl Sagan convinced NASA to turn the probe’s cameras back toward Earth to take a photograph of our planet from more than 4 billion miles away. The resulting image, known as the “Pale Blue Dot,” has become an iconic symbol of our place in the universe and a reminder of the fragility of our planet framing the cradle of all humanity in one incredible photo.
Lost in the universe
Voyager 1 is an outstanding achievement in human space exploration. Its discoveries have expanded our understanding of the outer reaches of our solar system and beyond, and it continues to provide valuable data about the nature of our universe. As the probe continues to travel through interstellar space, it symbolizes human curiosity and our desire to explore the unknown.