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Evidence Connecting Mercury's Magnesium Exosphere to Its Magnesium‐Rich Surface Terrane
Author(s) -
Merkel Aimee W.,
Vervack Ronald J.,
Killen Rosemary M.,
Cassidy Timothy A.,
McClintock William E.,
Nittler Larry R.,
Burger Matthew H.
Publication year - 2018
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2018gl078407
Subject(s) - exosphere , regolith , astrobiology , space weathering , mercury (programming language) , magnesium , planet , physics , astronomy , materials science , ion , asteroid , metallurgy , quantum mechanics , computer science , programming language
Mercury is surrounded by a tenuous, collisionless exosphere where the surface of the planet is directly exposed to the space environment. As a consequence, impacts and space weathering processes are expected to eject atoms and molecules from the surface into the exosphere, implying a direct link between the exospheric composition and the planet's regolith material. However, observational evidence demonstrating this link has been elusive. Here we report that exospheric magnesium, a species recently discovered and systematically measured by the Mercury Surface, Space ENvironment, GEochemistry, and Ranging mission, is enhanced when observed over a portion of the planet's surface regolith rich in magnesium. These observations confirm a direct link between Mercury's magnesium exosphere and the underlying crustal surface composition, providing strong evidence supporting theoretical arguments that impact vaporization can directly supply material to the exosphere from the regolith of a rocky, airless body.