The Elusive Origin of Mercury

Abstract

The MESSENGER mission sought to discover what physical processes determined Mercury's high metal to silicate ratio. Instead, the mission has discovered multiple anomalous characteristics about our innermost planet. The lack of FeO and the reduced oxidation state of Mercury's crust and mantle are more extreme than nearly all other known materials in the solar system. In contrast, moderately volatile elements are present in abundances comparable to the other terrestrial planets. No single process during Mercury's formation is able to explain all of these observations. Here, we review the current ideas for the origin of Mercury's unique features. Gaps in understanding the innermost regions of the solar nebula limit testing different hypotheses. Even so, all proposed models are incomplete and need further development in order to unravel Mercury's remaining secrets.

To appear in "Mercury: The View after MESSENGER" edited by Solomon, Nittler & Anderson (www.cambridge.org/9781107154452). This version is free to view and download for personal use only. Not for re-distribution, re-sale or use in derivative works. 37 pages, 5 figures

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Cited by in corpus (12)

• A giant impact as the likely origin of different twins in the Kepler-107 exoplanet system
• Nucleation and growth of iron pebbles explains the formation of iron-rich planets akin to Mercury
• The Exosphere as a Boundary: Origin and Evolution of Airless Bodies in the Inner Solar System and Beyond Including Planets with Silicate Atmospheres
• Explaining Mercury via a single giant impact is highly unlikely
• Modification of the composition and density of Mercury from late accretion
• The Cosmic Shoreline Revisited: A Metric for Atmospheric Retention Informed by Hydrodynamic Escape
• Mercury's formation within the Early Instability Scenario
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• White Paper on the Case for Landed Mercury Science
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