Demystifying science | The unfathomable universe of Voyager

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Voyager 1 And 2 were the first to study the satellites of the giant planets and exit a section of our solar system called the heliopause.

“I would say the most striking was the observation of volcanism on the moons of the giant planets, which was unexpected,” says Linda Spilker, chief scientist of the Voyager program at NASA. “The exit from the heliopause, the zone influenced by the solar wind rather than the interstellar wind, was also much later than expected. »

Marc Jobin, astronomer at the Planetarium, also spontaneously mentions the volcanism of the moons of giant planets, as well as the exit from the heliopause as the major contributions of the Voyager program.

M^me Spilker notes that Voyager 2 is until now the only probe to have flown past Neptune and Uranus.

She also took the only photo of a geyser rising 8 km above Neptune’s satellite Triton, coming from an underground ocean.

Launched in 1977, the two probes To travel left the solar system in 2012 and 2018. The probes Pioneer 10 And Pioneer 11, launched in 1972 and 1973, have also left the solar system, and it has not been possible to communicate with them for more than 20 years. The mission of Voyager 2, which was supposed to last five years, has just been extended until 2026 by eliminating a surge protection system that requires power. That of Voyager 1 should also benefit from this arrangement in 2024, when it will be located too far away for current systems to be sufficiently powered.

“We believe that the probes To travel will be able to continue sending scientific data until the 2030s,” says M^me Spilker, who began his career on Voyager in the 1970s, before moving to the Cassini program. ” The probe Cassini flew over Titan [une lune de Saturne] because Voyager 1 had not been able to penetrate its atmosphere, which intrigued us. » Voyager 1 could not fly past Neptune and Uranus, as Voyager 2because of his detour through Titan.

Respondents Cassini And Galileo also emerged in part because of observations of Jupiter by the Voyager program, which discovered rings not visible from Earth, like those of Saturn. Voyager 2 also found rings around Uranus, note M^me Spilker.

Both To travel will they provide important data in the coming years? “The influence of the solar wind lasts longer than expected after the heliopause,” says M^me Spilker. We expect to see the point where there will be changes in magnetism, when the interstellar wind will predominate. »