Study Suggests 2 Lost Super-Earths Reshaped Outer Solar System
Updated
Updated · Livescience.com · Jun 9
Study Suggests 2 Lost Super-Earths Reshaped Outer Solar System
1 articles · Updated · Livescience.com · Jun 9
Summary
122 selected simulations of the early outer solar system suggest one or two extra ice giants once orbited near Uranus and Neptune before being ejected into interstellar space.
20 million-year models found Jupiter’s moons stayed stable mostly in six-planet scenarios with two added worlds, while Uranus’ moons survived more often when only one extra giant planet was present.
Jupiter’s 1:2:4 resonance among Io, Europa and Ganymede points to a largely undisturbed history, while collisions among destabilized Uranian moons could help explain why Miranda contains about 50% more ice than its neighbors.
2 simulations still reproduced today’s system with both Jupiter’s and Uranus’ satellites surviving a single instability, leaving the study unable to rule out either one lost ice giant or two.
The March 25 Icarus paper says the missing planets were likely between Earth and Neptune in mass, and researchers now plan to probe Uranus’ moons for signs of past disruption.