The UI has been involved in many scientific breakthroughs over the years, and Thursday marked a historic breakthrough because of contributions of a UI scientist.

Thursday afternoon, scientists released strong evidence that spacecraft Voyager 1 has become the first human-made object to leave our solar system. UI physics/astronomy Professor Don Gurnett served the pivotal role of chief investigator in the development of the Voyager 1 spacecraft’s Plasma Wave Instrument 36 years ago.

The Voyager 1 mission launched in 1977, to fly to the outer planets and acquire photographs of previously unseen parts of the Solar System — including Jupiter, Saturn, Uranus, and Neptune.

“It turns out that if you launched the spacecraft in 1977, you could fly by all four of those planets,” Gurnett said. “They were kind of lined up, actually a little bit in a curve, which only happens every 180 years.”

Because of these specific alignment requirements, it was critical that the mission was launched between August and September 1977. Otherwise, it would not be possible for the spacecraft to fly past all four outer planets. Scientists succeeded in launching the mission within this timeframe, only to have to mission altered in 1979.

The alteration to the original plan was put into effect so the spacecraft would get a chance to fly by Saturn’s largest moon, Titan. Because of the change, the spacecraft had to forgo travel to Uranus and Neptune.

After the fly-by, the spacecraft was set on an outbound trajectory heading for the edge of the Solar System. 

“The reason that the Voyager mission is so important is that in astronomy books, a very substantial part of the book is pictures of Jupiter and its moons and all that stuff,” Gurnett said. “All those pictures were taken from Voyager. It was really a historic mission.”

Gurnett says the Voyager mission is a defining aspect of his 55-year career and said he believes that the mission is on a level comparable to NASA’s Hubble program in terms of scientific significance.

“In my opinion, it’s one of the greatest spaceflight missions NASA has ever undertaken,” Gurnett said. “Thirty-six years after launch, to actually penetrate into the interstellar plasma, it’s just a great engineering and scientific achievement.”