FORMATION OF THE TERRESTRIAL PLANETS FROM A NARROW ANNULUS

By Brad M. S. Hansen. 2009

227 citations recorded by the source corpus.

We show that the assembly of the solar system terrestrial planets can be successfully modeled with all of the mass initially confined to a narrow annulus between 0.7 and 1.0 AU. With this configuration, analogs of Mercury and Mars often form from the collisional evolution of material diffusing out of the annulus under the scattering of the forming Earth and Venus analogs. The final systems also possess eccentricities and inclinations that match the observations, without recourse to dynamical friction from remnant small body populations. Finally, the characteristic assembly timescale for Earth analogs is rapid in this model and consistent with cosmochemical models based on the 182Hf–182W isotopes. The agreement between this model and the observations suggests that terrestrial planet systems may also be formed in “planet traps,” as has been proposed recently for the cores of giant planets in our solar system and others.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/83442e5e4afd59a00343dd7e274d5fa379de4f0b

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Citations in the corpus

Building Terrestrial Planets (2012, background): “ real terrestrial planets. This trend continued in the simulations of Raymond et al. (2004, 2005, 2006b, 2007) and eventually led to AMDs consistent with that of the real system (Raymond et al. 2009; Hansen 2009). Instead, O’Brien et al. (2006) assumed that the initial disk consisted of a population”
Formation of planetary systems by pebble accretion and migration (2018, background): “This choice of the inner edge is also similar to the pragmatically chosen inner edge in terrestrial planet simulations (Hansen 2009).”
Close-in planetesimal formation by pile-up of drifting pebbles (2016, background): “Another solution to the low mass of the Mars problem is offered by the so-called pebble accretion scenario.”
Water delivery and giant impacts in the 'Grand Tack' scenario (2014, unknown): “The major advantages of terrestrial planet formation starting from a truncated disk, or annulus (Hansen, 2009), were conﬁrmed in this work.”
The Origin of the Moon Within a Terrestrial Synestia (2018, background): “Other N-body studies without fragmentation and with different initial conditions and alternative configurations of the giant planets (e.g., Hansen, 2009; Levison et al., 2015; O’Brien et al., 2006; Raymond et al., 2009; Walsh et al., 2011) all produce high-energy impacts in the final stages of…”
TESTING IN SITU ASSEMBLY WITH THE KEPLER PLANET CANDIDATE SAMPLE (2013, background): “Indeed, this might help to place our solar system in the Kepler context, as our own terrestrial planet system is potentially the outcome of a disk with a single localized planet trap (Hansen 2009).”
Accretion and differentiation of the terrestrial planets with implications for the compositions of early-formed Solar System bodies and accretion of water (2014, background): “An important insight into this problem has been made based on the idea of Hansen (2009).”
Populating the asteroid belt from two parent source regions due to the migration of giant planets—“The Grand Tack” (2012, background): “Hansen (2009) found that an outer edge to the planetesimal disk at 1 AU could solve the small Mars problem.”
The Non-carbonaceous–Carbonaceous Meteorite Dichotomy (2020, methodology): “This would produce in a natural way an asteroid population with a small total mass, as advocated in some models (Hansen 2009; Izidoro et al. 2016).”
MIGRATION THEN ASSEMBLY: FORMATION OF NEPTUNE-MASS PLANETS INSIDE 1 AU (2011, background): “…& Wetherill 1998; Agnor et al. 1999; Chambers 2001; Raymond et al. 2006), shows that configurations of three or four planets emerge naturally from an MMSN disk, although the low masses of Mercury and Mars in the solar system may require a more localized initial distribution of mass (Hansen 2009).”
EVIDENCE FROM THE ASTEROID BELT FOR A VIOLENT PAST EVOLUTION OF JUPITER's ORBIT (2010, background): “…constraints (Touboul et al., 2007; Allegre et al., 2008; Kleine et al., 2009) and numerical modeling (Chambers and Wetherill, 1998; Chambers, 2001; Raymond et al., 2006; O’Brien et al., 2006; Hansen, 2009; Morishima et al., 2010) suggest that the terrestrial planets took 30–100 My to form.”
A sawtooth-like timeline for the first billion years of lunar bombardment (2012, methodology): “The best available computer simulations of the terrestrial planet accretion process are those reported in Hansen (2009) and Walsh et al. (2011), mainly because they can satisfactorily reproduce the mass distribution and orbital characteristics of the terrestrial planets.”
Origin of water in the inner Solar System: Planetesimals scattered inward during Jupiter and Saturn's rapid gas accretion (2017, background): “This confined annulus of material can match the large Earth/Mars mass ratio (Hansen, 2009; Walsh and Levison, 2016).”