Unveiling Mercury's Geological Mysteries

Nov. 27, 2023

Salt glaciers, primordial atmosphere, and the new frontiers of astrobiology

Image shows a graphical representation of research about Mercury.

A view of Mercury’s north polar chaotic terrain (Borealis Chaos) and the Raditladi and Eminescu craters where evidence of possible glaciers has been identified.


Scientists from the Planetary Science Institute have uncovered evidence of potential salt glaciers on Mercury, opening a new frontier in astrobiology by revealing a volatile environment that might echo habitability conditions found in Earth's extreme locales.

"Our finding complements other recent research showing that Pluto has nitrogen glaciers, implying that the glaciation phenomenon extends from the hottest to the coldest confines within our solar system. These locations are of pivotal importance because they identify volatile-rich exposures throughout the vastness of multiple planetary landscapes," said Alexis Rodriguez, lead author of the paper "Mercury's Hidden Past: Revealing a Volatile-Dominated Layer through Glacier-like Features and Chaotic Terrains" that appears in the Planetary Science Journal.

PSI scientists Deborah Domingue, Bryan Travis, Jeffrey S. Kargel, Oleg Abramov, John Weirich, Nicholas Castle and Frank Chuang are co-authors of the paper.

"These Mercurian glaciers, distinct from Earth's, originate from deeply buried Volatile Rich Layers (VRLs) exposed by asteroid impacts. Our models strongly affirm that salt flow likely produced these glaciers and that after their emplacement they retained volatiles for over 1 billion years," said co-author Travis.

"Specific salt compounds on Earth create habitable niches even in some of the harshest environments where they occur, such as the arid Atacama Desert in Chile. This line of thinking leads us to ponder the possibility of subsurface areas on Mercury that might be more hospitable than its harsh surface."