Processes that lead to polar glaciers Mercury, the planet closest to the sun, has been modeled by a research team led by the University of Maine.
James Fastook, a computer science professor and researcher at UMaine's Climate Change Institute, and James Head and Ariel Deutsch of Brown University, studied the accumulation and flow of ice on Mercury, and how glacier deposits on the smallest planet in our solar system compare to those on Earth and Mars.
Their findings, published in the journal Icarus, adding to our understanding of how Mercury's ice accumulation – estimated to be less than 50 million years old and 50 meters thick – might have changed over time. Changes in the ice sheet serve as climate indicators.
Analysis of Mercury's cold-based glacier, which is located in a permanently shaded crater near the pole and seen by Earth-based radar, is funded by NASA. NASA's Solar System Research provides a grant to the Virtual Institute for Evolution and Environmental Exploration Objectives, and is part of the Study of volatile deposits on the moon.
Like the moon, Mercury does not have an atmosphere that produces snow or ice which can cause polar glaciers. Simulations by the Fastook team show that the planet's ice is deposited – possibly due to water-rich comets or other impact events – and remains stable, with little or no flow velocity. Despite the extreme temperature differences between the locations of permanent shaded glaciers on Mercury and the surrounding area illuminated by the sun.
One of the team's main scientific tools is the University of Maine Ice Sheet Model (UMISM), developed by Fastook with National Science Foundation funding. Fastook has used UMISM to reconstruct the shape and outline of past and present ice sheets on Earth and Mars, with findings published in 2002 and 2008 respectively.
"We expect deposits (on Mercury) to be limited to supply, and basically immovable deposits are stagnant, reflecting the extreme efficiency of the cold trap mechanism" in the polar region, according to the researchers.
Fajar maps the Ceres crater where ice can accumulate
James L. Fastook et al. Mercury Glaciation: The accumulation and flow of ice in the interior of a permanently shaded circum-polar crater, Icarus (2018). DOI: 10.1016 / j.icarus.2018.07.004