However, if they exert mutual forces on each other and the Sun takes up a finite volume, the gravitational and tidal forces exerted could lead to evolutionary scenarios so chaotic that one or more of these planets may eventually get ejected. With no way to gain or lose angular momentum, they remain in their elliptical orbits arbitrarily far into the future. The planets move in the orbits that they do, stably, because of the conservation of angular. This is completely negligible right now, changing Earth's orbit by only about a proton's width every million years or so. But right now, we're mostly struck only by solar wind particles: at the paltry clip of about 18,000 tons per year. In both cases, as this material collides with Earth, our orbit will change, with the exact changes dependent on the speed of the material relative to Earth: an inward migration when the Solar System forms and an outward migration at the Sun's end-of-life. It will be an enormous effect once again when the Sun enters the red giant phase of its life, as copious amounts of matter - about 33% of the Sun's total mass - will be ejected some 7.6 billion years from now. This was an enormous effect in the early days of the Solar System: back when we still had a protoplanetary disk of material surrounding our Sun. and the DSHARP collaboration, arXiv:1812.04040ΔΆ.) The Earth smashes into particles as it orbits the Sun. In the early stages of a solar system's formation, these protoplanetary disks cause dynamical friction, causing young planets to spiral inwards rather than complete perfect, closed ellipses. There is likely a very massive planet causing these spiral features, but that has yet to be definitively confirmed. The protostar IM Lup has a protoplanetary disk around it that exhibits not only rings, but a spiral.
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