Fig. 5
From: The relation between the surface composition anomaly and distribution of the exosphere of Mercury
Dependence of the Na relative production parameter on longitudes. In (a), Data with relative error of S(ϕ)/S(ϕ + π) is less than 5% are plotted. In (b), Data with relative error of S(ϕ)/S(ϕ + π) is less than 5% and with temperature above 550 K are plotted. The color of each dot represents the local time when the observations were performed