Jupiter May Have Destroyed Early Planets And Paved The Way For Earth

Composite image of Earth next to Jupiter. (Credit: NASA)

NASAs Kepler spacecraft has, to date, enabled astronomers to discover over 1,000 planets outside of our solar system. But theres a funny thing about the solar systems astronomers discovered they dont look much like ours at all. Most of them have larger, super-Earths planets smaller than Neptune but bigger than Earth located very close to the Sun.

Our solar system, by contrast, doesnt. Why?

Research conducted by astronomer Gregory Laughlin and astronomer/Forbes 30 Under 30 list member Konstantin Batygin suggest that the responsibility may lie with the planets Jupiter and Saturn.

In a paper published this week in the Proceedings of the National Academy of Sciences, the two astronomers suggest that in the early life of the solar system, Jupiter traveled much closer to the Sun than it is now close to 140 million miles away before reversing course and finding itself in its present orbit about 483 million miles from the Sun thanks to its gravitational interaction between the two gas giants.

Given Jupiters massive size, its strong gravity may have taken its toll on any super-Earths that existed in the early years of the Solar System by literally shifting their orbits so that they fell into the Sun.

In this scenario, the Solar Systems terrestrial planets formed from gas-starved mass-depleted debris that remained, the authors wrote in the paper.

All of this fits beautifully with other recent developments in understanding how the solar system evolved, while filling in some gaps, Batygin said in a statement.

The idea that Jupiter and Saturn once traveled closer to the Sun isnt original to this paper. Called the Grand Tack scenario, it was developed in part by a research group in 2001 and later revived again in 2011 to explain some of what astronomers were learning about the early Solar System. (Astronomer Kevin Walsh has a great page of resources about this theory that you can explore here.) For this research, Laughlin & Batygin ran computer simultations involving the Grand Tack scenario to see how it would impact the Solar System if, like most Solar Systems outside of ours, super-Earths had formed near the Sun.

Its the same thing we worry about if satellites were to be destroyed in low-Earth orbit. Their fragments would start smashing into other satellites and youd risk a chain reaction of collisions. Our work indicates that Jupiter would have created just such a collisional cascade in the inner solar system, Laughlin explained in a press release.

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Jupiter May Have Destroyed Early Planets And Paved The Way For Earth