The year is 1977. Jimmy Carter is sworn in as President of the United States. Brazilian soccer star Pele plays his last game in Japan. Star Wars Episode IV- A New Hope is dazzling audiences with droids and lightsabers. And in space, NASA launches Voyager 2 on August 20. Voyager 1 quickly follows its twin probe on September 5, 1977.
The voyagers are still on the cutting-edge of space exploration and remain the only probes to ever explore interstellar space or the the galactic ocean that our sun and its planets travel through. Part of what makes the sun and its planets so difficult to investigate is the heliosphere. The heliosphere is a protective bubble created by the sun’s magnetic field and an outward flow of charged particles from the sun called solar wind.
Heading into their 45th year of space service, the Voyager probes are a bit of an interstellar time capsule. According to NASA, they each carry an eight-track tape player to record data, contain about 3 million times less memory than modern cellphones, and transmit that data about 38,000 times slower than a current day 5G internet connection.
NASA notes that its researchers, some of whom are now younger than the Voyager probes themselves, are combining Voyager’s observations with data from newer space exploration missions to build a more complete picture of our sun and how the heliosphere interacts with interstellar space.
“The heliophysics mission fleet provides invaluable insights into our Sun, from understanding the corona or the outermost part of the Sun’s atmosphere, to examining the Sun’s impacts throughout the solar system, including here on Earth, in our atmosphere, and on into interstellar space,” said Nicola Fox, director of the Heliophysics Division at NASA Headquarters in Washington via press release. “Over the last 45 years, the Voyager missions have been integral in providing this knowledge and have helped change our understanding of the Sun and its influence in ways no other spacecraft can.”
Between the two probes, Voyager 1 and 2 have explored all the giant planets of our outer solar system (Jupiter, Saturn, Uranus and Neptune), 48 of their moons, and their unique system of rings and magnetic fields.
Should the Voyager spacecrafts bump into extra-terrestrial life, they are prepared with a message. A 12-inch gold-plated copper disk with recordings of sounds and images selected to “portray the diversity of life and culture on earth,” is loaded onto a phonograph. A committee chaired by the late Carl Sagan of Cornell University selected 115 images, a variety of natural sounds (songs and calls of the humpback whale included), music from different cultures, and greetings from Earth-people in 55 different languages.
As of April 2020, Voyager 1 is about 13.9 billion miles away from the sun, continuing its mission to explore the far reaches of the universe.
“Today, as both Voyagers explore interstellar space, they are providing humanity with observations of uncharted territory,” said Linda Spilker, Voyager’s deputy project scientist at NASA’s Jet Propulsion Laboratory in a press release. “This is the first time we’ve been able to directly study how a star, our Sun, interacts with the particles and magnetic fields outside our heliosphere, helping scientists understand the local neighborhood between the stars, upending some of the theories about this region, and providing key information for future missions.”