Fig. 9: Radiogenic heat-production rate required for basal melting compared with the age-dependent heat production rate of cosmochemically Earth-like planets.
From: Liquid water on cold exo-Earths via basal melting of ice sheets
a The black curve shows the radiogenic heat production rate as a function of time for cosmochemically Earth-like planets. The vertical extent of the error bars shows the heat production rate required for basal melting of ice sheets 1–20 km in thickness (also see Supplementary Fig. 2) on Proxima Centauri B, GJ 1061 (d), and TRAPPIST-1 (e). The dotted error bars show the range of heat production required for basal melting assuming Earth-like core mass fraction. The horizontal error bar shows the uncertainty in the age of these star systems. b–d Same as (a) but showing the range in the heat production rate and ages of various other exo-Earths listed in the legend. d A boxplot graph showing the range of heat flow required for basal melting on various exo-Earths as a function of the ice-thickness compared to the heat flow on Earth’s continents and oceans. The two thin, horizontal black lines show the range of heat flow on the Moon (lower line) and Mars (upper line). Source data are provided as a Source Data file.
