roots of ammonia and water that extend hundreds of miles deep. At the north and south poles, scientists were amazed to find cyclones packed like cinnamon buns—six at the north pole, nine at the south—all spinning the same direction.
They also found that Jupiter’s magnetic field is about twice as strong as scientists expected. And unlike Earth’s magnetic field—which arises from our planet’s core—Jupiter’s is surprisingly uneven between its poles. Bolton and others guess that just below the atmosphere, hydrogen is behaving like a metal, sparking part of Jupiter’s magnetism. Clues like these will lead to a better understanding of how planets form.
Bolton, who is also an associate vice president of the nonprofit Southwest Research Institute, oversees the Juno scientists who gather data as well as the engineers who control the spacecraft. “He has been an outstanding leader, and it’s not an easy job,” says David Stevenson, a senior Caltech theorist who has witnessed decades of solar system exploration. “He has this wonderful combination of leadership and scientific knowledge that motivates the mission.”
Bolton has also involved the public in groundbreaking ways. Juno’s website publishes raw images for citizen scientists to crop, color-correct and collage. Bolton’s friends in the music industry— ranging from the industrial musician Trent Reznor of Nine Inch Nails to the Greek composer Vangelis—have also boosted Juno’s popular appeal, creating Juno-related songs and film scores.
It’s a Renaissance approach Bolton finds deeply rewarding. After all, he points out, Galileo was an accomplished lute player before he observed Jupiter’s major moons. Three of those satellites have 1:2:4 harmonics: Every time Ganymede orbits Jupiter, Europa orbits twice and Io four times. Juno’s camera captured this celestial resonance for the first time and presented it to the public in a time-lapse video that’s been viewed more than two million times. “The innovation comes from the combination of analytic and creative thought,” Bolton says. “You couldn’t do Juno unless you had both halves of that.”