Voyager 1, on the other hand, took only two years to reach the gas giant. Launched on September 5, 1977, Voyager 1 made its closest approach on March 5, 1979. This was because the Voyager mission was designed to take advantage of an ideal layout of the outer planets. I strongly suspect Ted Simon, who’s now in his late eighties, is too much of a gentleman to brag about his achievements, so I shall do it for him. Forty years after Jupiter’s Travels was first published, it has been read by millions. It remains one of the most important and influential books ever written about motorcycle travel, inspiring generations to go forth and explore.

The end of a journey like the one I made is a very hard thing to negotiate because, after four years on the road, it is almost impossible to just resume normal service. You can’t. Everything becomes very turbulent. I was in real turmoil. And although I’d learned a huge amount about life, and about the world, and about everything, it wasn’t much help in solving my own personal problems. So, I made bad decisions and did strange things. a b c d e f g h Elkins-Tanton, Linda T. (2011). Jupiter and Saturn (reviseded.). New York: Chelsea House. ISBN 978-0-8160-7698-7. However, when Ted rolled into Egypt early in his journey, he found more pressing matters than road conditions were of concern. Weitering, Hanneke (January 10, 2018). " 'Totally Wrong' on Jupiter: What Scientists Gleaned from NASA's Juno Mission". space.com. Archived from the original on November 9, 2020 . Retrieved February 26, 2021.Wall, Mike (May 26, 2017). "More Jupiter Weirdness: Giant Planet May Have Huge, 'Fuzzy' Core". space.com. Archived from the original on April 20, 2021 . Retrieved April 20, 2021. Guillot, Tristan (1999). "Interiors of Giant Planets Inside and Outside the Solar System" (PDF). Science. 286 (5437): 72–77. Bibcode: 1999Sci...286...72G. doi: 10.1126/science.286.5437.72. PMID 10506563. Archived (PDF) from the original on October 9, 2022 . Retrieved April 24, 2022. Jupiter radiates more heat than it receives through solar radiation, due to the Kelvin–Helmholtz mechanism within its contracting interior. [65] :30 [66] This process causes Jupiter to shrink by about 1mm (0.039in)/yr. [67] [68] At the time of its formation, Jupiter was hotter and was about twice its current diameter. [69] Internal structure Diagram of Jupiter, its interior, surface features, rings, and inner moons.

Haisch Jr., K. E.; Lada, E. A.; Lada, C. J. (2001). "Disc Frequencies and Lifetimes in Young Clusters". The Astrophysical Journal. 553 (2): 153–156. arXiv: astro-ph/0104347. Bibcode: 2001ApJ...553L.153H. doi: 10.1086/320685. S2CID 16480998. Juno missions show that there are several polar cyclone groups at Jupiter's poles. The northern group contains nine cyclones, with a large one in the centre and eight others around it, while its southern counterpart also consists of a centre vortex but is surrounded by five large storms and a single smaller one for a total of 7 storms. [116] [117] Formation of Oval BA from three white ovalsBeginning in 1973, several spacecraft performed planetary flyby manoeuvres that brought them within observation range of Jupiter. The Pioneer missions obtained the first close-up images of Jupiter's atmosphere and several of its moons. They discovered that the radiation fields near the planet were much stronger than expected, but both spacecraft managed to survive in that environment. The trajectories of these spacecraft were used to refine the mass estimates of the Jovian system. Radio occultations by the planet resulted in better measurements of Jupiter's diameter and the amount of polar flattening. [55] :47 [171] Jovian is the adjectival form of Jupiter. The older adjectival form jovial, employed by astrologers in the Middle Ages, has come to mean 'happy' or 'merry', moods ascribed to Jupiter's influence in astrology. [22] The New Horizons mission took a more direct path after its January 19, 2006, launch. On February 28, 2007, it performed a flyby of Jupiter on its way to Pluto and other dwarf planets. The travel time to Jupiter was just over 13 months.