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Cosmic Billiards Leads to Inner Planetary Growth
The inner planets of our solar system may have collided with the material of their building blocks more than once to build up to their current size.
In the world of planetary formation, it feels like every week brings new unknowns as often as solved mysteries.
Let’s lay out some of the basics. In your mind’s eye, picture a newly formed star with a disk of gas and dust orbiting around it. Soon, that disk begins to have gaps, as small protoplanets begin to clump together, clearing paths as they orbit. Then the increasing gravity of those clumps pulls in more and more dust and gas until a planet actually exists in a lovely cleared orbit.
Yes, that’s the basic idea. Basics, however, never seem to satisfy scientists, who want to understand every detail possible and how changes in the steps affect the entire process. So research led by the University of Arizona Lunar and Planetary Laboratory set out to understand just how the conventional view of planetary accretion, where those tiny baby planets get bigger and bigger, exactly works. And, of course, it probably doesn’t work quite the way we thought. Quel surprise.
Rather than gently rounding up material as they rotate and revolve, it now seems…
