Open AccessHow did the equatorial ridge on Saturn's moon Iapetus form?
Author(s) -
Balcerak Ernie
Publication year - 2012
Publication title -
eos, transactions american geophysical union
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.316
H-Index - 86
eISSN - 2324-9250
pISSN - 0096-3941
DOI - 10.1029/2012eo140028
Subject(s) - ridge , geology , saturn , equator , solar system , astrobiology , debris , planet , astronomy , titan (rocket family) , paleontology , physics , geodesy , latitude , oceanography
Saturn's moon Iapetus is one of the most unusual moons in our solar system. Perhaps the most bizarre feature of Iapetus is its equatorial ridge, a 20‐kilometer‐high, 200‐kilometer‐wide mountain range that runs exactly along the equator, circling more than 75% of the moon. No other body in the solar system exhibits such a feature; as Dombard et al. show, previous models have been unable to adequately explain how the ridge formed. The authors propose that the ridge formed from an ancient giant impact that produced a subsatellite around Iapetus. Tidal interactions with Iapetus ultimately led to orbital decay, eventually bringing the subsatellite close enough that the same forces tore it apart, forming a debris ring around Iapetus. Material from this debris ring then rained down on Iapetus, the researchers say, creating the mountain ring along the equator. ( Journal of Geophysical Research‐Planets , doi:10.1029/2011JE004010, 2012)