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Saving the Earth with dynamical simulations

Model suggests how protoplanets kept a safe distance from the sun

A new model keeps the solar system safe for the young Earth and other infant planets by preventing them from spiraling into the sun.

When astronomers simulate the formation of the solar system, disaster strikes: no planets survive. Under most models’ assumptions, protoplanets would have collided with the parent star before they had a chance to fully form.

“This contradicts basic observational evidence: the fact that we are here,” said Mordecai-Mark Mac Low of the American Museum of Natural History at a press briefing January 7 at the winter meeting of the American Astronomical Society.

Planets form from a disk of gas and dust swirling around a young star. When the disk begins to coalesce into protoplanets, the gravity of those protoplanets pulls clumps of gas around the disk with them as they orbit the star. Gravitational perturbations from the clumps, in turn, can push the nascent planets into orbits closer to the parent star.

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