Modeling Cold Spots on Mercury: Opportunities for BepiColombo Observations

Abstract

Abstract “Cold spots” have been identified across the Moon as features with anomalously low nighttime temperatures emanating from small, young craters. The ESA/JAXA BepiColombo thermal radiometer will enable the first measurements of any cold spots on Mercury. Here we model temperatures of cold spots on Mercury for the time period of BepiColombo's mission. We find cold spots should be at least ∼6 K colder than their surroundings at all locations during the night, and up to ∼12 K colder at equatorial latitudes and hot‐pole longitudes. Cold spots will be coldest relative to their surroundings just after sunset and begin fading slightly during the long night before rapidly re‐equilibrating to their surrounding temperature at sunrise. We predict a cold spot formed from the impact of NASA's MESSENGER spacecraft would be ∼9 K colder than its surroundings at night, but only ∼145 m in diameter and so likely too small to be resolved.

Keywords

• Mercury
• Moon
• cold spots
• thermal modeling
• BepiColombo
• surface processes