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JOVIAN GENESIS


As the largest planet orbiting the sun, Jupiter has had a profound influence on the solar system. But its origin remains a profound mystery. To learn how Jupiter formed and how it has evolved, Juno will study the gas giant’s gravitational and magnetic fields, and explore the swirling clouds that form Jupiter’s colorful, trademark atmosphere. The spacecraft will also reveal what Jupiter is made of – and how much of it is water.    

HISTORY OF THE SOLAR SYSTEM –
THE MOTIVATION BEHIND THE JUNO MISSION

Four and a half billion years ago, a giant cloud of gas and dust, called a nebula, collapsed to form our solar system. Composed mainly of hydrogen gas, most of the nebula became the star we know as the Sun. The rest of the swirling cloud would condense to form earth and the other planets, asteroids and comets. It isn’t clear what triggered this collapse, but it does seem that whatever process produced our solar system is at work across the universe. We’ve observed half-formed stars – disks of gas in the midst of collapsing – and Jupiter-like planets orbiting other stars.

Jupiter was likely the first of the planets to form because it contains a lot of the same light gases that the sun is made of – hydrogen and helium. After the first few million years in the star’s life, it generated a wind that blew away most of the light gases that remained from the original nebula. For Jupiter to be primarily composed of hydrogen and helium, it must have formed while there was still a lot of those light gases around – when the solar system was young.

Since Jupiter is mainly made of the same stuff as the original nebula, the gas giant may hold clues about the origin of the solar system. As the nearest giant planet, studying Jupiter can also provide insight into planetary systems around other stars.


  • WHAT LED US TO JUNO?

    We’ve been studying Jupiter since Galileo first peered at the planet through his homemade telescope 400 years ago.


  • WHY JUPITER?

    Juno allows us to test different versions of the Jupiter story.


  • HOW DO WE STUDY JUPITER’S INTERIOR?

    We can’t observe Jupiter’s deep interior directly, but we can observe how the interior affects the space around the planet.


  • JUNO AND THE PUBLIC

    Juno will involve the public in new and unique ways.


  • HOW DOES JUNO REVEAL JUPITER’S FORMATION?

    Juno should provide a giant leap in our understanding of Jupiter’s formation.


  • WHAT’S IN A NAME?

    In Greek and Roman mythology, Jupiter drew a veil of clouds around himself to hide his mischief.


  • THE JOURNEY TO JUPITER

    Mission Juno is a once-in-a-lifetime opportunity to reach out and touch the planet that can help us understand our origins.


  • THE GALILEO PROBE

    Read more about the Galileo Probe.


  • WHERE IS JUNO NOW?

    Learn how you can see Juno’s current location


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