IOWA CITY, Iowa — Almost 47 years ago, two NASA spacecraft were destined for one of the greatest journeys through our solar system to fly by and learn about our outer gas giants.

They launched into a special planetary window that only occurs once every 176 years. It allows these spacecraft to use the gravitational pull of each planet they fly by to alter their trajectory, allowing them to reach the next planet in its path with minimal fuel usage.

The Voyager spacecraft paved the way for our understanding of our solar system, but now they are more than 15 billion miles away from Earth. It takes about 23 hours of light and radio signals to reach it one way, and it’s still changing our understanding of the cosmos.

The instruments still on board and operational were built and are still operated by the University of Iowa Department of Physics and Astronomy.

One of them is the Plasma Wave Subsystem, which measures subtle waves in the plasma fields around planets and in space.

The instrument has been instrumental in some of our most incredible discoveries in space, including the dataset that confirms when Voyager entered the interstellar medium beyond our solar system in 2012.

It was also a tooldetecting lightning on another planet for the first time in the early 80s. Lightning emits a wide range of electromagnetic waves. Because of the different speed at which each of these waves travel, a strange, descending sound is created.

This noise was captured by the University of Iowa’s instrument on the traveler as it flew, using the technique that first discovered the telltale sound of lightning when spies were trying to eavesdrop on their enemies in the early days of World War II World. .

The methodology shows how research over decades can continue to multiply one another, growing into larger discoveries over the years.

University of Iowa scientist and Voyager plasma wave co-investigator Dr. Bill Kurth was part of the instrument’s initial development nearly half a century ago and continues to monitor data sent back from the old spacecraft . until today.

While a graduate student, I worked on the hardware that would fly the Voyager spacecraft. I did my PhD thesis a month before Voyager 1 arrived at Jupiter, and then I asked if I could stay longer to see what kind of data we would get. I didn’t realize I would still be doing this 45 years later,” said Dr. Kurth.

I think it’s a real thrill, every time I look at a new data file, I realize I’m seeing something no one has seen before.

As spacecraft continue to age, instruments are shut down to conserve energy and extend the lifespan of the spacecraft. Of the nearly 10 instruments on board, only four remain. The University of Iowa instrument that still helps us understand our place in the stars is one of them still in operation.

It is not yet certain how long the probes have left, but predictions show that they could arrive in the early 2030s. However, they will still float through the vastness of space, probably outliving our own star, the sun, long after they close.

You and find more information about The University of Iowa’s involvement in the Voyager missions here or their involvement in a multitude of flagship NASA missions here.

To follow along with Voyager or learn more about Voyager, see the links below from NASA’s mission pages.