'Modest, humble, and uncommonly smart': How a Soviet mathematician quietly solved the mystery of planet formation


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Mar 18, 2008
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It is interesting to look at trail blazers here and how the modeling for the solar nebula developed over the decades, what is presented today, and what is documented among the exoplanets now, example. https://skyandtelescope.org/astronomy-news/how-did-two-hot-and-super-dense-neptunes-form/

My observation. Here is a 1977 report on the MMSN. The Distribution of Mass in the Planetary System and Solar Nebula, https://ui.adsabs.harvard.edu/abs/1977Ap&SS..51..153W/abstract, September 1977. The arXiv paper, https://articles.adsabs.harvard.edu/pdf/1977Ap&SS..51..153W, 19-Feb-1977.

The table in the paper shows MMSN values 0.01 to 0.07 solar masses and disk mass distribution for the planets so they can evolve from the disk. Total disk mass ranges 0.01 to 0.07 solar masses, 3.329428E+03 (3329.428) earth masses up to 2.330599E+04 (23305.99) earth masses in the protoplanetary disk said to evolve into the solar system we see today. The 1977, six-page paper at the end “4. Conclusions” indicates the MMSN creates an anomalously low mass region for Mercury, Mars, and the asteroids. Some values for the MMSN range 0.01 to 0.1 solar masses in the disk. 0.1 solar mass disk = 3.329428E+04 (33,294.28) earth masses. Much work is done now to refine the MMSN, dust, gas, and mass distribution in the postulated protoplanetary disk that creates the solar system we see today using a timescale of some 4.5 billion years or so. Comparing the 1977 MMSN to present day ALMA disk observations should be interesting too. Looks like much juggling takes place to get the protoplanetary disk to fall into place and create the solar system we see today. When I read the more current computer simulation models and reports like phys.org publishes or sometimes, space.com, I look for tables like the 1977 paper disclosing disk mass for different regions used in the simulations to create the solar system. Hard to find such clarity it seems.

My note. New computer models for simulating the origin of Mercury use perhaps 2 or 3 earth masses in the original, protoplanetary disk and still fail in many simulations. The terrestrial, rocky planets, Mercury, Venus, Earth, and Mars are difficult to show how they evolved from the postulated, early protoplanetary disk in our solar system. References, Dynamical Avenues for Mercury's Origin. I. The Lone Survivor of a Primordial Generation of Short-period Protoplanets, https://ui.adsabs.harvard.edu/abs/2021AJ....161..240C/abstract, May 2021. Dynamical Avenues for Mercury's Origin. II. In Situ Formation in the Inner Terrestrial Disk, https://ui.adsabs.harvard.edu/abs/2021AJ....162....3C/abstract, July 2021.

My note about the main belt asteroids in the MMSN. A typical orbital period is about 4.4 years so in one billon years, main belt asteroids could complete more than 227 million revolutions around the Sun in the heliocentric solar system. There is the potential for a wide range of primordial asteroid belt mass here (4.5 billion years old solar system model) because of the possible ejections and mass loss rate(s) compared to the present asteroid belt we see using telescopes. Then we have the exoplanet solar system TRAPPIST-1 with 7 exoplanets (about 5.6 earth masses total), all orbiting well inside of where Mercury is at in our solar system with computer simulations reporting the need for a large disk mass relative to the tiny, 0.08 solar mass host star in efforts to show accretion for these 7 exoplanets from the postulated primordial protoplanetary disk.