Juno spacecraft’s first flyby to Jupiter gives us an abundance of new information about the planet. This research makes us rethink our previous idea of not only Jupiter but also of the formation of planetary systems. The findings feature in two papers, both published in the journal Science.
We have a new picture of Jupiter: the planet is not exactly like we used to think of it, suggests the new data from the first flyby of NASA’s Juno spacecraft. The scientists behind the research started off with a preconceived notion of Jupiter which they have had to retract, explains Juno mission leader, Scott Bolton.
Juno reached within 5,000 kilometres to Jupiter’s clouds last year, on August 27. This marks the first time we have such a close view at the gas giant. Unsurprisingly, we got to learn about Jupiter like we never did before—we now have more details about the planet’s gravity, magnetic field, and weather system.
Scientists previously believed that Jupiter had a uniform surface hiding beneath the thick clouds gracing its sky. The new data, on the other hand, suggests a more complex existence. For instance, when its gravity was measured, the results suggested that the planet’s core was not solid and compact. Rather, the core would be diffuse, and as large as half the Jupiter’s radius—a revelation that proved to be extremely surprising to the world of science. More research now needs to be conducted to gain a better understanding of the core; this would be no easy feat, comments planetary scientist Imke de Pater (not involved in the study) from the University of California.
Another interesting finding entails Jupiter’s powerful magnetic field: it happens to be the strongest in our solar system. Furthermore, some regions were characterised with a magnetic field almost two times stronger than what was expected while other areas had weaker magnetism. The varying strengths of the magnetic field throughout the planet suggests that it comes from electric currents circulating in a layer of molecule hydrogen forming the outer part of Jupiter.
This magnetic field appears to be interacting with the solar wind, suggests the second study, led by astrophysicist John Connerney. This association causes changes in the auroras of Jupiter. Thankfully, Juno was able to take ultraviolet and infrared images of this phenomenon. Investigating the occurrence of the auroras, the scientists found a resemblance to the event on Earth: particles could be seen fallen into the atmosphere of Jupiter. A difference between the two planets, though, is that Jupiter has beams of electrons emanating from its atmosphere.
It was also discovered that ammonia is released from Jupiter’s atmosphere in a manner similar to a phenomenon on Earth whereby warm air situated at the equator rises, thereby generating trade winds and hurricanes. However, Jupiter lacking a solid surface suggests that the ammonia upwelling would not function in the same way as it does on our planet. Understanding how it really works promises to reveal more about other planets’ atmospheres, given that Jupiter is considered a model for all gas giants. As Bolton says, studying Jupiter will influence our understanding of all giant planets.