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Moon and Jupiter

April 17, 2016

When the skywatchers of ancient times named Jupiter after the king of the gods, they had no way of knowing how fitting that title really was. Jupiter is the largest and heaviest planet in the solar system, with the strongest gravitational influence. And it may have used that influence quite liberally when the solar system was young.

There’s evidence that Jupiter and the other giant planets moved around during their early days. Jupiter may have moved as close to the Sun as Mars is today. As it did so, its gravity would have pushed any small, rocky planets into the Sun. As Jupiter moved out to its current position, Earth and the other present-day rocky planets were then born from leftover debris. But Jupiter blocked the formation of another planet from debris beyond the orbit of Mars. Today, that material forms the asteroid belt.

Last year, researchers reported that Jupiter might have kicked another giant out of the solar system. They determined that the orbits of a couple of Jupiter’s moons were changed by an encounter with a planet as big as Neptune, the fourth-largest planet.

And early this year, other researchers reported that Jupiter or Saturn might have ejected a rocky world about 10 times as massive as Earth. That planet may reside far from the Sun, where its gravity pushes around many smaller worlds.

And the king of the planets is in great view tonight. It stands quite close to the upper left of the Moon this evening, and looks like a brilliant star.


Script by Damond Benningfield

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