5:15 PM - 6:30 PM
[PAE16-P07] Possible Verifications for the Inner Void Model of Rapid Planet Formation
Keywords:planet formation, unified model, solar system verifivation
We have developed a new model of rapid planet formation. This model is based on the scenario that all the planets and cores are formed at the outer edge of the inner gas void at the radius of around 0.04AU, and then gravitationally shot toward the middle of the protoplanetary disk. In this paper, we improve this model with the results of possible verifications of this model.
The model avoids the general problem of the dust-fall toward the central star before planet formation. Due to the magnetorotational instability or any interaction with the central star, a gas-free region (void) with a radius of about 0.04 AU (astronomical unit) from the central star is assumed. Dust falls to its outer edge and accumulates there. Dense dust collides with each other a coherent Kepler motion is realized. Here, gas is involved and runaway accretion occurs, resulting in Hot Jupiter (HJ) and dust lumps of various sizes. The former heavy body sling-shots the latter light bodies in and out, which forms cold gas planet (CG) by the gas accretion. Lighter dust clumps are shot out to the outer edge of the disk and released to the outside of the system at a certain rate to become interstellar planets and dust lumps. On the other hand, dust that has fallen from the outside into the gas gap created by CG forms a lump of ice. (Arxiv 2007.15979). We verify our model based on the basic predictions of the model.
A rapid decrease of dust: This model promotes the rapid formation of planets: 50 years for dust fall, 200 years for dust accumulation in the dense environment, and less than 5000 years for the sling-shot. Thus the planets can have almost the same composition and are rapidly formed at the same time. This is compared with the observations such as C.F.Manara 2018, and μ54Fe verification by M. Schiller, et al., 2020. Verification from the magma ocean of the Earth. In our rapid formation model, the earth was also blown by a slingshot from 0.04 AU with an equilibrium temperature of less than 2000 K. Therefore, the Earth magma ocean has been there from the beginning. According to L. Piani et al., 2020, the Earth's hydrogen can be supplied from the Enstatite Chondrite in the mantle, and its chemical composition is consistent. In this case, the Earth's water has been naturally present, and the late heavy bombardment hypothesis would not be needed. The origin of the Moon. The Giant Impact hypothesis is popular but this cannot explain the similarity in composition of elements of the moon and the earth. On the other hand, the separation theory (the moon jumped out of the earth) best describes this elemental composition while the rotation was not sufficient for the separation. In our model, the tidal force of the slingshot gives 10 times the force required for the separation and enables the separation of the moon and the earth. The element composition ratio of all planets (cores) within a system is the same in our model. This result is compared with the observation by A. E. Doyle1 et al. 2019 which concludes the composition of six planets roasted by white dwarfs is the same as those for Earth, Mars, and Mercury. Planet cores and small dust masses are all undergoing thermal metamorphism in our model because the radius 0.04 AU corresponds to the equilibrium temperature 2000 K which naturally yields thermal metamorphism. In particular, smaller dust masses are blown to the outer periphery of the disk and bear a hot history of thermal metamorphism. On the other hand, at the outer edge of the gap created by the gas giant in the middle of the disk, the dust mass bears a cold history while adhering ice. These outer hot and inner cold sources mix to form meteorites, comets, and asteroids. This is compared with the results of the Stardust exploration (H. Bortman 2006). Further predictions of our model can be checked: A possibility of simple cooling of the earth; Many interstellar rogue planets; Origin of the spin of the planets and satellites.
The model avoids the general problem of the dust-fall toward the central star before planet formation. Due to the magnetorotational instability or any interaction with the central star, a gas-free region (void) with a radius of about 0.04 AU (astronomical unit) from the central star is assumed. Dust falls to its outer edge and accumulates there. Dense dust collides with each other a coherent Kepler motion is realized. Here, gas is involved and runaway accretion occurs, resulting in Hot Jupiter (HJ) and dust lumps of various sizes. The former heavy body sling-shots the latter light bodies in and out, which forms cold gas planet (CG) by the gas accretion. Lighter dust clumps are shot out to the outer edge of the disk and released to the outside of the system at a certain rate to become interstellar planets and dust lumps. On the other hand, dust that has fallen from the outside into the gas gap created by CG forms a lump of ice. (Arxiv 2007.15979). We verify our model based on the basic predictions of the model.
A rapid decrease of dust: This model promotes the rapid formation of planets: 50 years for dust fall, 200 years for dust accumulation in the dense environment, and less than 5000 years for the sling-shot. Thus the planets can have almost the same composition and are rapidly formed at the same time. This is compared with the observations such as C.F.Manara 2018, and μ54Fe verification by M. Schiller, et al., 2020. Verification from the magma ocean of the Earth. In our rapid formation model, the earth was also blown by a slingshot from 0.04 AU with an equilibrium temperature of less than 2000 K. Therefore, the Earth magma ocean has been there from the beginning. According to L. Piani et al., 2020, the Earth's hydrogen can be supplied from the Enstatite Chondrite in the mantle, and its chemical composition is consistent. In this case, the Earth's water has been naturally present, and the late heavy bombardment hypothesis would not be needed. The origin of the Moon. The Giant Impact hypothesis is popular but this cannot explain the similarity in composition of elements of the moon and the earth. On the other hand, the separation theory (the moon jumped out of the earth) best describes this elemental composition while the rotation was not sufficient for the separation. In our model, the tidal force of the slingshot gives 10 times the force required for the separation and enables the separation of the moon and the earth. The element composition ratio of all planets (cores) within a system is the same in our model. This result is compared with the observation by A. E. Doyle1 et al. 2019 which concludes the composition of six planets roasted by white dwarfs is the same as those for Earth, Mars, and Mercury. Planet cores and small dust masses are all undergoing thermal metamorphism in our model because the radius 0.04 AU corresponds to the equilibrium temperature 2000 K which naturally yields thermal metamorphism. In particular, smaller dust masses are blown to the outer periphery of the disk and bear a hot history of thermal metamorphism. On the other hand, at the outer edge of the gap created by the gas giant in the middle of the disk, the dust mass bears a cold history while adhering ice. These outer hot and inner cold sources mix to form meteorites, comets, and asteroids. This is compared with the results of the Stardust exploration (H. Bortman 2006). Further predictions of our model can be checked: A possibility of simple cooling of the earth; Many interstellar rogue planets; Origin of the spin of the planets and satellites.