As of Update 24, Universe Sandbox simulates several surface properties of [[Planetary Body]] objects in two dimensions, to represent the variation in these properties across the surface of each object. The Surface view at the top of an object's [[View Panel]] can display a [[Surface Map|map]] representing any of these properties.
==Related Properties & Settings==▼
The following properties can be simulated:
*[[Surface Simulation#Temperature|Temperature]] represents the surface temperature at each point on the map.
*[[Surface Simulation#Elevation and Displacement|Elevation]] represents the height of each point on the map.
*[[Surface Simulation#Elevation and Displacement|Displacement]] represents the change in the height of each point of the map relative to the original elevation.
*[[Surface Simulation#Vapor Flow|Vapor Mass]] represents the amount of vapor (water or CO<sub>2</sub> in its gas state) in each point on the map.
*[[Surface Simulation#Liquid Flow|Water/Liquid CO<sub>2</sub> Depth]] represents the height of the surface of the water (or liquid CO<sub>2</sub>) above the sea floor in each point on the map.
*[[Surface Simulation#Material Phases|Ice Thickness]] represents the thickness of the ice (solid water or CO<sub>2</sub>) layer in each point on the map.
*[[Surface Simulation#Lapse Rate and Snow|Lapse Rate]] represents the rate at which temperature changes with altitude. This property depends on the [[Surface Pressure|surface pressure]] of the object and determines where snow appears on the surface.
▲==Related Properties & Settings==
The Temperature layer represents the surface temperature of each point on the map of the object's surface. The [[Temperature Calculation|temperature calculations]] consider the effects of incoming heat from sources like nearby stars, the effects of cooling, and the spread of heat across the surface of the object.
===Elevation and Displacement===
The Elevation map of an object can currently be changed via impacts, which will create craters that will decrease the elevation in some areas of the surface, and material is excavated, and increase the elevation in other areas, as debris is deposited on the surface.
[[File:Resolution Comparison.png|thumb|'''Left:''' The Earth with no water, seen with the default Universe Sandbox view. '''Right:''' The Elevation map drawn on the Earth's surface.]]
Universe Sandbox includes a graphical representation of snow that will be present on mountain peaks above a certain elevation if water is present. The snow is not directly simulated, like ice and water are.
The resolution of the simulated surface of an object in Universe Sandbox is generally lower than the resolution of the [https://en.wikipedia.org/wiki/Heightmap heightmap] used to display the object in a simulation. This is due to the performance demands of surface simulation. If Universe Sandbox used only the Temperature map to calculate where snow should be displayed on the surface, the distribution of snow would have a lower resolution than the rest of the graphical surface.
Universe Sandbox tracks three [https://en.wikipedia.org/wiki/Phase_(matter) phases] of a surface material (either water or CO<sub>2</sub>) across the surface of the object. At every [[Time Step|time step]], at every point on the surface map, Universe Sandbox calculates how much of this material will exist as a solid, liquid, or gas. The temperatures at which the material changes between these phases (e.g., the [[Boiling Point]] or [[Freezing Point]]) depend on several properties of the object, including its [[Surface Pressure]].
The amount of material that exists as a solid at a given point on the surface is represented by the Ice Thickness, the amount