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Tuesday, March 24, 2015
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Jupiter migration in the early Solar System
Jupiter’s orbital migration in its early history may explain why the structure of the Solar
System differs from most extrasolar systems, according to a study. The Solar System, with
low-mass inner planets relatively far from the Sun, may be an anomaly compared with most
known extrasolar planetary systems, which feature large planets orbiting close to their star.
Konstantin Batygin and Greg Laughlin modeled planetary formation in the early Solar
System and found that inward migration of Jupiter from an orbit of more than 5 astronomical
units (AUs) to around 1.5 AUs, followed by outward orbital migration, may explain the low
mass of inner rocky planets. Inward migration of Jupiter may have entrained and
shepherded small planetary precursors, initiating a collisional cascade in the inner Solar
System. The aerodynamic evolution of the generated planetesimal swarm likely facilitated
orbital decay of preexisting planets and planetesimals close to the Sun, potentially explaining
the lack of large planets close to the star. The remaining volatile-poor, mass-depleted debris
would then have formed into the inner planets. The results suggest that stars that harbor
giant planets with orbital periods longer than 100 days may be unlikely to host multiple closein planets, and that Earth-sized close-in planets may be uninhabitable and enriched in
volatiles, according to the authors.
Article #14-23252: “Jupiter’s decisive role in the inner Solar System’s early evolution,” by
Konstantin Batygin and Greg Laughlin.
MEDIA CONTACT: Konstantin Batygin, Division of Geological and Planetary Sciences,
California Institute of Technology, Pasadena, CA; tel: 617-794-4302; e-mail:
<[email protected]>
http://www.eurekalert.org/jrnls/pnas/14-23252.htm
AFTER THIS ARTICLE PUBLISHES, it will be available at
http://www.pnas.org/cgi/doi/10.1073/pnas.1423252112