National Aeronautics and Space Administration

How did the sun's family of planets and minor bodies originate? Missions for 'operating' phase.

For the first time in human history we know of planets around other stars and many of those other planetary systems look quite different from our own. Many have a planet like Jupiter, or even bigger, nearest to the Sun. If we are to understand why this is the case, and how likely it is that there are Earth-like planets elsewhere, we need to better understand how planets form.

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