recursal/Fanatic-Fandom huggingface dataset:
Planetary Body

A Planetary Body in Universe Sandbox is a simulated object that is massive enough to be spherical and to have a significant gravitational effect on other objects, but is not massive enough to qualify as a Star or a Black Hole. Planetary Bodies can represent a variety of actual celestial objects, including exoplanets, planets, moons, and larger Solar System objects.

Planetary Body objects may be further subcategorized as Terrestrial Planets, Gas Giants, and Planetoids.

## Properties Panel

The properties panel for a Planetary Body object will include the following tabs:

* Overview
* Motion
* Surface
* Composition
* Visuals
* Actions

## Characteristics

Planetary Body objects have the following sets of characteristics:

* They are attracting objects, meaning that they exert a gravitational force on other objects in the simulation.
* They are attracted objects, meaning that they feel the effects of gravity from other attracting objects in the simulation.
* They have calculated orbital elements, and their orbit can be displayed.
* They can collide with other objects, and produce fragments.
* Their surface properties, including surface temperature, are simulated in two dimensions.
* They have a simulated composition.
* They may have an atmosphere.
* They may have a magnetic field.
Supernova Cloud

A Supernova Cloud in Universe Sandbox is a simulated object representing a cloud of hot gas ejected by a recent supernova.

## Properties Panel

The properties panel for a Supernova Cloud object will include only a Nova tab.

## Characteristics

Supernova Cloud objects have the following characteristics:

* They are not affected by gravity, so they are neither attracted nor attracting.
* They have no calculated orbital elements, and their orbit will not be displayed.
* They do not collide with other objects, instead passing right through them.
Selected Cell Longitude

The Longitude indicates the longitude coordinate of the selected cell on its grid. Negative values correspond to West longitude, while positive values correspond to East longitude.

## Property Details

### Location

The Longitude property is located in the Selected Grid Cell section of the Surface tab in the object's properties panel.
Surface Heat Capacity

The Surface Heat Capacity of an object represents the energy required to raise the temperature of one unit of surface area by one degree. This property is related to the heat capacity of the object's surface material, and determines how fast the surface will heat or cool.

## Property Details

### Location

For Planetary Body objects, the Surface Heat Capacity property can be found in the Energy Flow section of the Surface tab. For Stars, Black Holes, Fragments, and Human-Scale Objects, the Surface Heat Capacity property can be found in the Temperature tab.

### Units

Effective Temperature can be viewed using the following units:

* Megajoules per Kelvin per Meter Squared (MJ/K/m2 or MJ/C/m2) = 105 J/K/m2
* Joules per Kelvin per Meter Squared (J/K/m2 or J/C/m2) uses the SI unit for energy, temperature, and area

## Simulation Effects

### Surface Temperature

At each simulation time step, the change in the temperature of each point on the object's surface, Δ*T*, is calculated using the Energy Absorption Rate, *Pabs*, the Energy Radiation Rate, *Prad*, the time step, Δ*t*, and the object's Surface Heat Capacity, *C*, using

Δ
# T
(

P

a
b
s

−

P

r
a
d

)
Δ
T

/

C
.

{\displaystyle \Delta T = (P\_{abs} - P\_{rad})\Delta T / C. }
Time Zone

The Time Zone setting controls which time zone the date and time of the current simulation will be displayed in the bottom bar. There are two options: Local, which uses the user's time zone, and Universal (UTC), which uses Coordinated Universal Time, also known as Greenwich Mean Time (GMT).

## Setting Details

The Time Zone setting is located in the Time section of the Sim Settings Menu.
Roche Lobe Radius

The Roche Lobe Radius property of an object represents the size of the object's Roche lobe: the region around the object where smaller objects would be gravitationally bound to it, rather than to a second object in the simulation.

This is a **read-only** property that is automatically calculated by Universe Sandbox based on the mass of the object, *m*1 the mass of the second object, *m*2 and the distance between them, *d*, using

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{\displaystyle R\_{roche} = 0.866 d \frac{0.49 (\frac{m\_1}{m\_2})^{2/3}}{0.6 (\frac{m\_1}{m\_2})^{1/3} + \ln{(1 + (\frac{m\_1}{m\_2})^{1/3})}}.}

If there are multiple other objects in the simulation, the Roche Lobe Radius property will display the smallest Roche lobe size for this object.

## Property Details

### Location

The Roche Lobe Radius property is located in the Tidal Effects section of the Motion tab of the object's properties panel.

### Units

Roche Lobe Radius can be viewed using the following properties:

* Milky Way Galaxy radius (milky way) = 5.5×104 light year
* Parsec (parsec) = 3.08568025×1016 m
* Light-year (light year) = 9.46073047×1015 m
* Astronomical Unit (AU) = 1.495978707×1011 m
* Solar radius (sun) = 6.955×108 m
* Lunar distance (lunar dist) = 3.844×108 m
* Light-second (light sec) = 2.99792458×108 m
* Jupiter radius (jupiter) = 6.9911×107 m
* Earth radius (earth) = 6.37101×106 m
* Moon radius (moon) = 1.7371×106 m
* Kilometer (km) = 1000 m
* Meter (m) is the SI base unit for length
* Centimeter (cm) = 0.01 m
* Millimeter (mm) = 0.001 m

## References

1. ↑ Binaries and Stellar Evolution, Onno Pohls, Utrecht University
Nebula Tab

The Nebula tab in an object's properties panel displays the properties of a Galaxy Nebula object, including nebula-specific properties. The name of the Galaxy that the nebula is a part of is listed at the top of the Nebula tab. Clicking on this name will select the galaxy and display the Galaxy tab in place of the Nebula tab in the properties panel.

* Uncategorized
	+ Name
	+ Mass
	+ Radius
	+ Density
	+ Age
* Content
	+ Enable Nebula Evolution
	+ Gas Fraction
	+ Star Fraction
	+ Dust Fraction
	+ Average Star Temperature
	+ Star Count
* Motion
	+ Relative to
	+ Distance
		- Position Vector
	+ Speed
		- Velocity Vector
	+ Distance to You
Magnetic Pole Angle

The Magnetic Pole Angle represents the angle between the axis of the object's magnetic field and its rotation axis.

## Property Details

### Location

The Magnetic Pole Angle is located in the Magnetic Fields section at the bottom of the Composition tab in the object's properties panel.

### Units

Magnetic Pole Angle is an angle, and can be viewed or edited using the following units:

* Radians (rad)
* Degrees (°) = (180/π) rad

Magnetic Pole Angle is only defined in the range 0-180°, or 0-π rad.
Stellar Heating

One of the sources of heat energy that can change the temperature of an object is heat received from stars in the simulation. This stellar energy is produced inside the star and radiated in all directions out into space. Any object with a direct line-of-sight to the star will receive a fraction of the energy.

## Related Properties & Settings

### Properties

* The rate at which energy is added to the object from stellar sources is shown in the Stellar Power property.
* The amount of heating depends on the Luminosity of the star.
* Stellar heating will affect an object's Average Temperature or Surface Temperature.

## Models

Every star in a simulation radiates energy out into space. The rate at which the energy is emitted, also known as the emitted power, is called the star's Luminosity. For an object located a distance

D

{\displaystyle D}

 from the star with luminosity

L

{\displaystyle L}

, the power per area received by the object is

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{\displaystyle F\_{star}={\frac {L}{4\pi D^{2}}}.}

Power per area is sometimes called flux density or irradiance.

The larger the object is, the more total power it will receive from the star. This total power depends on the cross-sectional area of the object. For a sphere (like a planet or moon) with radius

R

{\displaystyle R}

, cross-sectional area is

π

R
2

{\displaystyle \pi R^2}

, and the total power received from the star is

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{\displaystyle P\_{rec}=F\_{star}\pi R^{2}={\frac {LR^{2}}{D^{2}}}.}

A fraction of the received energy will be absorbed by the object, and the rest will be reflected back into space. Only the absorbed energy will affect the object's temperature. The fraction of energy reflected into space is represented by the object's albedo,

a

{\displaystyle a}

, so the rate at which energy is absorbed from the star, or the Stellar Power, is

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{\displaystyle P\_{star}=P\_{rec}(1-a)={\frac {LR^{2}}{4D^{2}}}(1-a).}
Fragment

A **Fragment** in Universe Sandbox is a simulated object that is too small to have a significant gravitational effect on other objects. Fragments are produced by processes like collisions, Roche fragmentation, and friction fragmentation, and are also used to represent smaller Solar System objects.

## Properties Panel

The properties panel for a Fragment object will include the following tabs:

* Overview
* Temperature
* Composition
* Visuals
* Actions

## Characteristics

Fragment objects have the following characteristics:

* They are non-attracting objects, meaning that they do **not** exert a gravitational force on other objects in the simulation.
* They are attracted objects, meaning that they feel the effects of gravity from other attracting objects in the simulation.
* They have no calculated orbital elements, and their orbit will not be displayed.
* They can collide with other objects.
* They have a single Surface Temperature rather than a two-dimensional simulation of temperature across the surface.
Enable Nebula Evolution

The Enable Nebula Evolution property of a Galaxy Nebula object determines whether Galaxy Nebula Evolution is simulated for that nebula. The Enable Nebula Evolution property of a Galaxy object controls the Enable Nebula Evolution properties for each individual nebula in the galaxy.

## Property Details

### Location

The Enable Nebula Evolution property for an individual Galaxy Nebula object is located in the Content section of the Nebula tab in the nebula's properties panel. The Enable Nebula Evolution property for a Galaxy object is located at the bottom of the Properties section of the Galaxy tab of the galaxy's properties panel.
Life Likelihood

The **Life Likelihood** property of an object is a measure of how similar the object's habitability-related properties are to the Earth's. The Life Likelihood property is **read-only** and is calculated automatically by Universe Sandbox.

Universe Sandbox calculates an object's Life Likelihood based on its Earth Similarity Index, tangential speed at equator, liquid level, and atmosphere mass. The Life Likelihood is given by

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{\displaystyle LL=(ESI\*LL\_{spin}\*LL\_{water}\*LL\_{atmo})^{1/4},}

where *ESI* is the Earth Similarity, and *LL**spin*, *LL**water*, and *LL**atmo* are the individual contributions to the Life Likelihood of the tangential speed at equator, liquid level, and atmosphere mass, respectively. For example, if the object's tangential speed at equator is *v**obj* and the Earth's is *v**earth*, then the contribution of tangential speed at equator to Life Likelihood is

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{\displaystyle LL\_{spin}=\left(1-{\frac {v\_{obj}-v\_{earth}}{v\_{obj}+v\_{earth}}}\right)^{w\_{spin}}.}

The contribution of each property is weighted according to the following values:

* *w**ESI* = 2.57
* *w**spin* = 0.87
* *w**water* = 1.70
* *w**atmo* = 4.32

Properties with larger weights have larger effects on the object's Life Likelihood.

## Property Details

### Location

The Life Likelihood property of an object is located in the Comparisons section of the Composition tab of the object's properties panel.
Delete Object

The Delete Object action will remove the selected object from the simulation.

## Property Details

### Location

The Delete Object button can be found at the bottom of the Overview tab of an object's properties panel, as well as in the Actions tab.

A selected object can also be removed from the simulation using the Delete or Backspace button on the keyboard.
Tidal Heating Effect

The Tidal Heating Effect property of an object represents the amount of energy the object will absorb over time due to tidal heating. This is a **read-only** property that is automatically calculated by Universe Sandbox.

## Property Details

### Location

The Tidal Heating Effect property is located in the Tidal Effects section in the Motion tab of the object's properties panel.

### Units

Tidal Heating Effect can be viewed using the following units:

* Yottawatts (YW) = 1024 W
* Zetawatts (ZW) = 1021 W
* Exawatts (EW) = 1018 W
* Petawatts (PW) = 1015 W
* Terawatts (TW) = 1012 W
* Gigawatts (GW) = 109 W
* Megawatts (MW) = 106 W
* Kilowatts (kW) = 1000 W
* Watts (W) is the SI unit for power, or energy per time.
Selected Cell Water Vapor Pressure

The Water Vapor Pressure property indicates the pressure of the water vapor in the selected cell.

## Property Details

### Location

The Water Vapor Pressure property is located in the Selected Grid Cell section of the Surface tab in the object's properties panel.

### Units

Water Vapor Pressure can be viewed and edited using the following units:

* Standard atmosphere (atm) = 101325 Pa
* Bar (bar) = 100000 Pa
* Kilopascal (kPa) = 1000 Pa
* Millibar (mbar) = 100 Pa
* Pascal (Pa) is the SI unit for pressure.
Gravitational Lens Appearance

The Gravitational Lens property of a Black Hole object determines the source of the object's color. The property has two options: Default and Custom. When the Gravitational Lens is set to Custom, the color of the distorted region around the black hole can be set by the user. When the Gravitational Lens is set to Default, this region will be transparent.

## Property Details

### Location

The Gravitational Lens property is located in the Layers section of the Visuals tab of the object's properties panel.
Ice Appearance

The Ice Appearance control determines whether simulated ice is displayed on the object's surface.

The checkbox on the left of the control determines whether the object's ice is displayed. The color setting on the right of the control sets the color of the ice.

## Property Details

### Location

The Ice Appearance control is located in the Layers section of the Visuals tab of an object's properties panel.
Supernova Heating

One of the sources of heat energy that can change the temperature of an object is heat received from a recent supernova in the simulation. This energy is produced by the supernova explosion and radiated in all directions out into space. Any object with a direct line-of-sight to the supernova will receive a fraction of the energy.

## Related Properties & Settings

### Properties

* The rate at which energy is added to the object from supernova sources is shown in the Supernova Power property.
* The amount of heating depends on the Luminosity of the supernova.
* Supernova heating will affect an object's Average Temperature or Surface Temperature.

## Models

Every supernova in a simulation radiates energy out into space. The rate at which the energy is emitted, also known as the emitted power, is called the supernova's Luminosity. The luminosity of a supernova will change over time, increasing rapidly until it peaks and then slowly fading with time. For an object located a distance

D

{\displaystyle D}

 from the supernova with luminosity

L

{\displaystyle L}

, the power per area received by the object is

F

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v
a

=

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.

{\displaystyle F\_{nova}={\frac {L}{4\pi D^{2}}}.}

Power per area is sometimes called flux density or irradiance.

The larger the object is, the more total power it will receive from the supernova. This total power depends on the cross-sectional area of the object. For a sphere (like a planet or moon) with radius

R

{\displaystyle R}

, the total power received from the supernova is

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{\displaystyle P\_{rec}=F\_{nova}4\pi R^{2}={\frac {L^{2}R^{2}}{D^{2}}}.}

A fraction of the received energy will be absorbed by the object, and the rest will be reflected back into space. Only the absorbed energy will affect the object's temperature. The fraction of energy reflected into space is represented by the object's albedo,

a

{\displaystyle a}

, so the rate at which energy is absorbed from the supernova, or the Supernova Power, is

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{\displaystyle P\_{nova}=P\_{rec}(1-a)={\frac {L^{2}R^{2}}{D^{2}}}(1-a).}
Rotation Axis

An object's rotation axis is the line through the object that the object rotates around. The orientation of the line is represented by the object's Obliquity and Argument of Obliquity properties, and the angle of rotation about the axis is represented by the object's Yaw property. The speed of the rotation is represented by the Rotational Period property.
Elliptical Ratio

The Elliptical Ratio property of an elliptical galaxy is a measure of how much the galaxy's shape varies from perfectly spherical. The Elliptical Ratio is the ratio of the length of the shortest axis of the galaxy to the length of the longest axis of the galaxy. For example, if the galaxy's length is twice its height, the Elliptical Ratio is 0.5. A perfectly spherical galaxy will have an Elliptical Ratio of one.

## Property Details

### Location

The Elliptical Ratio property is located in the Elliptical section of the Galaxy tab of the galaxy's properties page. This section is only visible for elliptical galaxies.
Stellar Power

The Stellar Power property of an object represents the rate that energy from stellar heating is absorbed by the object over time. Stellar Power is a **read-only** property that is continually calculated by Universe Sandbox.

## Property Details

### Location

For Planetary Body object, the Stellar Power property is located in the Energy Flow section of the object's Surface tab, when the Energy Absorption Rate property is expanded. For Stars, Black Holes, Fragments, and Human-Scale Objects, the Stellar Power property is located in the Temperature tab.

### Units

Stellar Power can be viewed using the following units:

* Solar luminosity (L star) = 3.846×1026 W
* Watts (W) is the SI unit for luminosity.

## Simulation Effects

### Temperature

Stellar Power is one of several sources of energy that can increase an object's Average Temperature or Surface Temperature.
Motion Tab

The Motion tab in an object's properties panel displays properties related to the motion of the object in space, including its orbital elements if the object is in orbit around another object, its rotation properties, and motion-related actions.

* Uncategorized
	+ Relative to
		- Orbital Parent
	+ Distance
		- Position Vector
	+ Speed
		- Velocity Vector
* Orbital Elements
	+ Orbital Parent
	+ Orbital Period
	+ Semi-Major Axis
	+ Pericenter Distance
	+ Apocenter Distance
	+ Eccentricity
	+ Inclination
	+ Argument of Pericenter
	+ Longitude of the Ascending Node
	+ True Anomaly
	+ Mean Anomaly
* Rotation
	+ Rotation Relative to
	+ Obliquity
	+ Argument of Obliquity
	+ Yaw
	+ Rotational Period
	+ Tangential Speed at Equator
	+ Tidally Lock
* Tidal Effects
	+ Roche Lobe Radius
	+ Tidal Stress Direction
	+ Tidal Stress Magnitude
	+ Tidal Heating Effect
* Impacting Objects
	+ Strongest Attractor
	+ Orbital Parent
* Camera Relative
	+ Normalized Light Curve
	+ Radial Velocity
	+ Camera Inclination
	+ Camera Azimuth
	+ Distance to You
* Actions
	+ Position Lock
	+ Auto Orbit
	+ Zero Velocity
Temperature Tab

The Temperature tab in an object's properties panel displays properties related to the object's temperature.

* Uncategorized
	+ Surface Temperature
* Energy Flow
	+ Energy Absorption Rate
		- Fusion Power
		- Stellar Power
		- Supernova Power
		- Tidal Power
		- Gas Drag Power
	+ Energy Radiation Rate
	+ Heating Rate
	+ Equilibrium Temperature
	+ Surface Heat Capacity
	+ Average Albedo
	+ Effective Temperature
Freezing Point

The Freezing Point (also known as the melting point) of an object represents the temperature at which water will change from the solid to liquid state. Above this temperature, the water will exist as a liquid or gas, and below this temperature, it will exist as a solid.

This property is read-only and is automatically calculated by Universe Sandbox based on the Surface Pressure of the object.

## Property Details

### Location

The Freezing Point property is located in the Water section of the Surface tab of the object's properties panel.

### Units

Freezing Point can be viewed using the following units:

* Kelvin (K) is the SI base unit for temperature
* Degrees Fahrenheit (°F)
* Degrees Celsius (°C)

Conversions between these three units are as follows:

°C = K - 273

°F = (9/5)°C + 32
Total Water Mass

Total Water Mass indicates the total mass of water present on the object's surface, in the gas, liquid, and solid phases. Total Water Mass is equal to the sum of the Total Water Vapor Mass, the Total Liquid Water Mass, and the Total Ice Mass.

## Property Details

### Location

The Total Water Mass property of an object is located in the Water section of the Surface tab in the object's properties panel.

### Units

Total Water Mass can be viewed and edited using the following units:

* Milky Way Galaxy mass (milky way) = 1.5×1012 sun
* Solar mass (sun) = 1.9891×1030 kg
* Jupiter mass (jupiter) = 1.8986×1027 kg
* Earth mass (earth) = 5.97219×1024 kg
* Moon mass (moon) = 7.349×1022 kg
* Earth ocean mass (ocean) = 1.4×1021 kg
* Earth atmosphere mass (atmosphere) = 5.158×1018 kg
* Kilogram (kg) is the SI base unit for mass
* Gram (g) = 1×10-3 kg
* Milligram (mg) = 1×10-6 kg
Spiral Arms

The Spiral Arms property of a spiral galaxy indicates the number of arms in the galaxy. A spiral galaxy can have between zero and six arms, although a spiral galaxy with zero arms is automatically categorized as a type S0.

## Property Details

### Location

The Spiral Arms property is located in the Spiral section of the Galaxy tab of the galaxy's properties panel. This section is only visible for spiral galaxies.
Equilibrium Temperature

The Equilibrium Temperature of an object represents the Average Temperature of Surface Temperature that the object would have if it were in thermal equilibrium. In other words, the temperature such that the object's Energy Absorption Rate equals its Energy Radiation Rate. At any given time, the object will be heating or cooling in order to change its Average Temperature to match this Equilibrium Temperature.

Equilibrium Temperature is a **read-only** property, and is continually recalculated as time passes in the simulation. At very high temperatures, a Planetary Body object will evaporate.

## Property Details

### Location

For Planetary Body objects, the Equilibrium Temperature property can be found in the Energy Flow section of the Surface tab. For Stars, Black Holes, Fragments, and Human-Scale Objects, the Equilibrium property can be found in the Temperature tab.

### Units

Equilibrium Temperature can be viewed using the following units:

* Kelvin (K) is the SI base unit for temperature
* Degrees Fahrenheit (°F)
* Degrees Celsius (°C)

Conversions between these three units are as follows:

°C = K - 273

°F = (9/5)°C + 32
Dust Fraction

The Dust Fraction property of a Galaxy Nebula object represents the fraction of the object's mass that is present in dust, relative to the amount of mass in gas or stars. The Dust Fraction affects the object's appearance, as dust will appear as an opaque cloud in the nebula. The Dust Fraction, Gas Fraction, and Star Fraction values will always sum to 100%.

The Dust Fraction is automatically calculated by Universe Sandbox based on the Galaxy Type and the nebula's position within the Galaxy. However, the user can change the Dust Fraction, which will automatically turn off the Enable Nebula Evolution toggle for the individual nebula.

## Property Details

### Location

The Dust Fraction property is located in the Content section in the Nebula tab of the nebula's properties panel.

### Units

Dust Fraction is a unitless property between 0 and 1, but it can be viewed and edited as either a fraction or a percentage.
True Anomaly

The True Anomaly of an object describes the object's position along its orbit. It represents the angle between the pericenter (the point where the object is closest to its Orbital Parent) and the object's current position.

True Anomaly is one of six orbital elements that describe an object's orbit.

## Property Details

### Location

The True Anomaly property is located in the Orbital Elements section of the Motion tab of an object's properties panel, if that object has an Orbital Parent.

### Units

True Anomaly is an angle, and can be viewed or edited using the following units:

* Radians (rad)
* Degrees (°) = (180/π) rad

True Anomaly is defined in the range from -180° to +180°, or -π to π rad.
Interface Color

The Interface Color property of an object determines the color of the object's displayed trail and orbit, among other interface elements. The property has two options: Default and Custom. When the Interface Color property is Custom, the color of these elements can be set by the user.

## Property Details

### Location

The Interface Color property is located in the Properties section of the Visuals tab of the object's properties panel.

## Simulation Effects

### Default Color

For known planets planets in the Solar System, including Venus, Earth, and Mars, the Default color of the planet's interface elements is set by the Universe Sandbox databases. For other objects, the default interface color is randomly generated.

### Custom Color

The Custom interface color of an determines the color of the object's trail, orbit, label, icon, selection circle, and the color of the line representing that object in a Graph.
Surface Map

For each surface property simulated by Universe Sandbox, a 2D heat map of the property can be displayed using the View Panel.

These data maps can also be displayed directly on the 3D surface of the object in the simulation using the Surface menu in the Visuals tab.

The map is a 2D representation of the object's surface, divided into a rectangular grid of cells. The color of each cell represents the value of the surface property at that point on the surface. The resolution of the map, or the number of grid cells, depends on the performance demands of the simulation.

The following types of data maps can be displayed for Terrestrial Planet or Planetoid objects:

* Surface Temperature
* Sea Level Temperature
* Elevation
* Displacement
* Water Vapor Pressure
* Liquid Water Depth
* Ice Thickness

For Gas Giant objects, which have no solid surface and thus no valid elevation or material phase simulation, only the Surface Temperature and Sea Level Temperature maps will be displayed.

## Selecting Grid Cells

Hovering over a single cell in the grid will display the value of the displayed surface property in that cell. Clicking the cell will display all surface property values for that cell in the Selected Grid Cell section of the Surface tab.

## Legend

A horizontal legend appears below the map, displaying the values represented by the map colors. A dropdown menu to the right of the legend controls the units used. The legend can be toggled on and off in the 2D View Settings menu.

## Color Scheme

The color scheme used in the map can be changed using the Gradient setting in the 2D View Settings menu. The Logarithmic setting in this menu will determine whether the color scheme is linear or logarithmic.
Base Color

The Base Color property of a Terrestrial Planet or Planetoid determines the source of the object's surface colors. The property has two options for its Source setting: Map, which will apply a known surface map, or Elevation, which will color the surface by local elevation.

## Property Details

### Location

The Solid Surface property is located in the Layers section of the Visuals tab of the object's properties panel.

### Settings

#### Source

Determines whether the surface of the object is colored according to a known Map, or colored by Elevation.

#### Map

This setting will appear when Source is set to Map. It provides a list of surface maps for known Solar System objects, including Earth, Mars, Venus, Pluto, and the Moon. Any of these known surface maps can be applied to the object.

#### Colors

This setting will appear when Source is set to Elevation. When the user changes the High/Middle/Low elevation colors, the Colors setting will change to Custom. When changed back to Default, the original elevation colors will be restored.

#### High/Middle/Low

These three color settings determine the colors of each elevation range on the object.

## Simulation Effects

### Default Color

For known terrestrial planets and some planetoids in the Solar System, including Mercury, Venus, Earth, Mars, Pluto, and Ceres, the Default appearance of the object's surface is set by the Universe Sandbox database to match the known appearance of these planets. For other terrestrial planets and planetoids, the surface colors depend on elevation, and the three elevation colors (see below) are randomly generated.

### Custom Color

The Custom colors of a terrestrial planet or planetoid determine the appearance of the object's surface. The color of any point on the surface is based on the point's elevation. Three elevation colors, representing the colors at High, Middle, and Low elevation, can be set by the user.
Black Hole

A Black Hole in Universe Sandbox is a simulated object representing an actual black hole, or a new black hole created by the user.

A Galaxy object is made up of several Galaxy Nebula objects and a single Black Hole (see Galaxy Structure). A Black Hole in a Galaxy will exert a gravitational force on other objects in the simulation based on the total mass of the galaxy, rather than the mass of the Black Hole itself.

## Properties Panel

The properties panel for a Black Hole object will include the following tabs:

* Overview
* Motion
* Temperature
* Composition
* Visuals
* Actions

## Characteristics

Black Hole objects have the following sets of properties:

* They are attracting objects, meaning that they exert a gravitational force on other objects in the simulation.
* They are attracted objects, meaning that they feel the effects of gravity from other attracting objects in the simulation.
* They have calculated orbital elements, and their orbit can be displayed.
* They can collide with other objects.
* They have a simulated composition.
Delete Supernova

The Delete Supernova action removes all Supernova Cloud objects associated with the supernova from the simulation. This action does not remove the Supernova Remnant from the simulation.

## Property Details

### Location

The Delete Supernova button is located in the Actions section of the Nova tab in the supernova cloud's properties panel.
Surface Lock

Surface Lock is a feature that automatically adjusts the visible rotation and lighting of an object so the user to clearly see its surface. This can be particularly helpful when experimenting with surface simulation.

The toggle to enable the Surface Lock feature is located in the View menu in the bottom bar. Once enabled, Surface View can be activated by zooming in on a selected object, and deactivated by zooming out.

Once activated, the camera will rotate with the object, allowing a stable view of the object's surface even if the object is rotating. The user can still rotate the object to see different parts of the object's surface. The Lighting of the simulation will also automatically switch to Surface Illumination to increase the visibility of the surface, and the Background will fade to a single color, with other objects in the simulation visible as they move by.
Reload Simulation

The Reload Simulation action will reset the simulation and all settings to its initial state. If the simulation was originally created as a New simulation, the simulation will be completely empty once again.

## Setting Details

The Reload Simulation button, labeled Restart, is located in the Time menu in the bottom bar.
Escape Velocity

The Escape Velocity of an object is the speed that a second object would need to have in order to overcome gravity to escape the surface of the first object. An object with a mass of *M* and a radius of *R* in a simulation with gravitational constant *G* will have an escape velocity of

v

e

=

2
G
M

R

.

{\displaystyle v\_{e}={\sqrt {\frac {2GM}{R}}}.}

Escape Velocity is a **read-only** property that is calculated automatically by Universe Sandbox.

## Property Details

### Location

The Escape Velocity property of an object is located in the Cumulative Properties section of the Composition tab of the object's properties panel.

### Units

Escape Velocity can be viewed using the following properties:

* The Speed of Light (lightspeed) = 2.99792458×108 m/s
* Kilometers per Second (km/s) = 1000 m/s
* Meters per Second (m/s) is the SI unit for speed
* Kilometers per Hour (km/h) = 0.2778 m/s
Fusion Power

The Fusion Power property of an object represents the rate that energy from internal fusion is added to the object over time. Fusion Power is a **read-only** property that is continually calculated by Universe Sandbox. Fusion Power is zero only greater than zero for planets and stars with masses larger than 13 Jupiter masses.

## Property Details

### Location

For Planetary Body object, the Fusion Power property is located in the Energy Flow section of the object's Surface tab, when the Energy Absorption Rate property is expanded. For Stars, Black Holes, Fragments, and Human-Scale Objects, the Fusion Power property is located in the Temperature tab.

### Units

Fusion Power can be viewed using the following units:

* Solar luminosity (L star) = 3.846×1026 W
* Watts (W) is the SI unit for luminosity.

## Simulation Effects

### Temperature

Fusion Power is one of several sources of energy that can increase an object's Average Temperature or Surface Temperature.
Gas Fraction

The Gas Fraction property of a Galaxy Nebula object represents the fraction of the object's mass that is present in gas, relative to the amount of mass in stars or dust. The Gas Fraction affects the object's appearance, as gas will appear as a glowing cloud in the nebula. The Gas Fraction, Star Fraction, and Dust Fraction values will always sum to 100%.

The Gas Fraction is automatically calculated by Universe Sandbox based on the Galaxy Type and the nebula's position within the Galaxy. However, the user can change the Gas Fraction, which will automatically turn off the Enable Nebula Evolution toggle for the individual nebula.

## Property Details

### Location

The Gas Fraction property is located in the Content section in the Nebula tab of the nebula's properties panel.

### Units

Gas Fraction is a unitless property between 0 and 1, but it can be viewed and edited as either a fraction or a percentage.
Cloud Mass

The Cloud Mass property of a Supernova Cloud object represents the total mass of material contained within all of the Supernova Clouds originating from this supernova. This property is **read-only** and is automatically calculated by Universe Sandbox.

## Property Details

### Location

The Cloud Mass property is located in the Properties section of the Nova tab in the Supernova Cloud's properties panel.

### Units

Cloud Mass can be viewed and edited using the following units:

* Milky Way Galaxy mass (milky way) = 1.5×1012 sun
* Solar mass (sun) = 1.9891×1030 kg
* Jupiter mass (jupiter) = 1.8986×1027 kg
* Earth mass (earth) = 5.97219×1024 kg
* Moon mass (moon) = 7.349×1022 kg
* Earth ocean mass (ocean) = 1.4×1021 kg
* Earth atmosphere mass (atmosphere) = 5.158×1018 kg
* Kilogram (kg) is the SI base unit for mass
* Gram (g) = 1×10-3 kg
* Milligram (mg) = 1×10-6 kg
Surface Temperature

The Surface Temperature of an object represents the average temperature of the surface of an object. Object types including Stars, Black Holes, Fragments, and Human-Scale Objects have only a single Surface Temperature property to represent the temperature of the entire surface of the object.

## Property Details

### Location

The Surface Temperature property of a Star, Black Hole, Fragment, or Human-Scale object can be found in the Overview tab and at the top of the Temperature tab.

The Surface Temperature of an object is also displayed in its mini-info panel.

### Units

Surface Temperature can be viewed and edited using the following units:

* Kelvin (K) is the SI base unit for temperature
* Degrees Fahrenheit (°F)
* Degrees Celsius (°C)

Conversions between these three units are as follows:

°C = K - 273

°F = (9/5)°C + 32
Sea Level

The Sea Level of an object represents the expected elevation of liquid water, assuming it is distributed across the surface and settled into low-lying areas, measured from the lowest point on the object's Elevation map. The Surface Temperature of different points of the object's surface is calculated using each point's Sea Level and the object's Lapse Rate. The user can also change the Sea Level, which will change the Total Liquid Water Mass and Total Water Mass of the object.

## Property Details

### Location

The Sea Level property of a Planetary Body can be found in the Water section of the Surface tab.

### Units

Sea Level can be viewed using the following units:

* Milky Way Galaxy radius (milky way) = 5.5×104 light year
* Parsec (parsec) = 3.08568025×1016 m
* Light-year (light year) = 9.46073047×1015 m
* Astronomical Unit (AU) = 1.495978707×1011 m
* Solar radius (sun) = 6.955×108 m
* Lunar distance (lunar dist) = 3.844×108 m
* Light-second (light sec) = 2.99792458×108 m
* Jupiter radius (jupiter) = 6.9911×107 m
* Earth radius (earth) = 6.37101×106 m
* Moon radius (moon) = 1.7371×106 m
* Kilometer (km) = 1000 m
* Meter (m) is the SI base unit for length
* Centimeter (cm) = 0.01 m
* Millimeter (mm) = 0.001 m
Pulse Tool

The Pulse Tool launched a ring or sphere of particles from a selected object. The particles will move outwards away from the object.

## Tool Details

### Location

The Pulse button is located in the Tools menu in the bottom bar. When clicked, a menu will appear containing the settings.

### Settings

There are a number of settings affecting the shape and speed of the group of particles produced by the Pulse tool.

* Shape
	+ Determines whether the particles will be produced in a ring or a sphere
* Plane Alignment
	+ If Ring is chosen for shape, the Plane Alignment will determine whether the ring is orientated relative to the Simulation Grid or the object's orbital plane.
* Particles
	+ The number of particles produced
* Speed
	+ The initial speed of the particles as they move away from the object
Universe Sandbox Wiki/Section 2

Guides

* Getting Started
* Interface
* Object Types
* VR

* Support
* About

Object Properties

* Overview
* Motion
* Composition
* Surface
* Temperature
* Visuals
* Actions

* Galaxy
* Nebula
* Nova
* Barycenter

Simulated Scientific Phenomena

* Gravity
	+ N-Body Simulation
	+ Roche Fragmentation
* Collisions
	+ Collision Simulation
	+ Momentum Conservation
	+ Mass Conservation
	+ Collision Fragmentation
	+ Friction Fragmentation
* Heating
	+ Temperature Calculations
	+ Collision Heating
	+ Tidal Heating
	+ Evaporation
* Surface Simulation
	+ Lasers

* Composition
	+ Materials
	+ Magnetic Fields
	+ Atmospheres
	+ Life Simulation
* Stars
	+ Stellar Evolution
	+ Supernova
	+ Stellar Wind
	+ Stellar Prominence
	+ Habitable Zone
* Galaxies
	+ Galaxy Structure
	+ Galaxy Types
	+ Galaxy Nebula Evolution
Lighting

The Lighting setting of a simulation determines how light reflects off objects, making them visible to the camera.

There are three options for lighting objects in a simulation, based on the source of light:

* Realistic
	+ Light is produced by stars. If there are no stars present in the simulation, objects are lit from the negative z-direction.
* Studio
	+ Light is produced by a virtual light source from behind the camera to the upper left.
* Flashlight
	+ Light is produced by a virtual light source from the direction of the camera.

## Related Settings

The Lighting setting is located in the View menu in the bottom bar, or in the full View Settings menu.

The brightness of the light source can be controlled by the Intensity setting in the View Settings menu.
Irregular Galaxy

An Irregular Galaxy is a type of Galaxy object representing a specific irregular-type galaxy, or a new irregular galaxy created by the user. Irregular galaxies can have a variety of shapes, and do not meet the requirements to be classified as spiral or elliptical galaxies.

## Related Properties and Settings

### Properties

* The Galaxy Type is located in the Galaxy tab of the Galaxy's properties panel.

## Models

The structure of an irregular galaxy is very simple. Galaxy Nebula objects in the galaxy are given randomly oriented, circular orbits around the central black hole, and the size of the orbits is constrained by the galaxy's radius.

There is minimal simulated evolution of the Galaxy Nebula objects in an irregular galaxy. The Average Star Temperature of the nebulae in an irregular galaxy is randomly chosen, and the Dust Fraction for all nebula is set to 0%.
Barycenter Velocity

The Total Velocity property of a Barycenter object represents the Velocity Vector of the barycenter, relative to the Simulation Grid. This property is a 3D vector, with x-, y-, and z-components. Total Velocity is a **read-only** property that is automatically calculated by Universe Sandbox.

## Property Details

### Location

The Total Mass property is located near the top of the Barycenter tab in the barycenter's properties panel.

### Units

Each component of the Total Velocity can be viewed and edited using the following units:

* The Speed of Light (lightspeed) = 2.99792458×108 m/s
* Kilometers per Second (km/s) = 1000 m/s
* Meters per Second (m/s) is the SI unit for speed
* Kilometers per Hour (km/h) = 0.2778 m/s
Stellar Wind

Stellar wind refers to the flow of gas particles ejected from the upper atmosphere of a star. Stellar wind from the Sun is sometimes referred to as solar wind.

## Related Properties & Settings

### Properties

* The stellar wind from any stars in a simulation will affect the Magnetosphere Size of a Planetary Body object.

## Models

Universe Sandbox simulates stellar wind only through its effect on an object's magnetosphere. In the Universe Sandbox model, stellar wind is spherically symmetric, and the stellar wind pressure due to a star with a luminosity of *L* at a distance *D* from the object is

# P

L

4
π

D
2

c

,

{\displaystyle P = \frac{L}{4\pi D^2 c},}

where *c* is the speed of light.
Average Star Temperature

The Average Star Temperature of a Galaxy Nebula object is the average Effective Temperature of the stars represented by the nebula. These stars are not simulated with individual Star objects, so this average temperature is not calculated from the stars. However, the color of the nebula is based on this temperature, allowing Universe Sandbox to simulate effects like the blue color of the arms in a spiral galaxy, or the redder color of an elliptical galaxy. Lower temperatures are represented by colors towards the red end of the spectrum, while higher temperatures are represented by bluer colors.

Average Star Temperature is automatically calculated by Universe Sandbox based on the Galaxy Type and the nebula's position within the Galaxy. However, the user can change the Average Star Temperature, which will automatically turn off the Enable Nebula Evolution toggle for the individual nebula.

## Property Details

### Location

The Average Star Temperature property is located in the Content section of the Nebula tab in the nebula's properties panel.

### Units

Average Star Temperature can be viewed and edited using the following units:

* Kelvin (K) is the SI base unit for temperature
* Degrees Fahrenheit (°F)
* Degrees Celsius (°C)

Conversions between these three units are as follows:

°C = K - 273

°F = (9/5)°C + 32
Distance to Closest Star

The Distance to Closest Star property of an object represents the distance between the object and the closest Star in the simulation. If there is no star in the simulation, the Distance to Star will read No Stars Present. If the object is the only star in the simulation, the Distance to Closest Star will be zero.

Distance to Closest Star is a **read-only** property, as it is calculated automatically by Universe Sandbox based on the locations and types of objects in the simulation.

## Property Details

### Location

The Distance to Closest Star property is not listed in an object's property panel, but can be graphed.

### Units

Distance to Closest Star can be viewed using the following units:

* Milky Way Galaxy radius (milky way) = 5.5×104 light year
* Parsec (parsec) = 3.08568025×1016 m
* Light-year (light year) = 9.46073047×1015 m
* Astronomical Unit (AU) = 1.495978707×1011 m
* Solar radius (sun) = 6.955×108 m
* Lunar distance (lunar dist) = 3.844×108 m
* Light-second (light sec) = 2.99792458×108 m
* Jupiter radius (jupiter) = 6.9911×107 m
* Earth radius (earth) = 6.37101×106 m
* Moon radius (moon) = 1.7371×106 m
* Kilometer (km) = 1000 m
* Meter (m) is the SI base unit for length
* Centimeter (cm) = 0.01 m
* Millimeter (mm) = 0.001 m
Selected Cell Water Vapor Mass

The Water Vapor Mass property indicates the mass of the water vapor in the selected cell.

## Property Details

### Location

The Water Vapor Mass property is located in the Selected Grid Cell section of the Surface tab in the object's properties panel.

### Units

Water Vapor Mass can be viewed and edited using the following units:

* Milky Way Galaxy mass (milky way) = 1.5×1012 sun
* Solar mass (sun) = 1.9891×1030 kg
* Jupiter mass (jupiter) = 1.8986×1027 kg
* Earth mass (earth) = 5.97219×1024 kg
* Moon mass (moon) = 7.349×1022 kg
* Earth ocean mass (ocean) = 1.4×1021 kg
* Earth atmosphere mass (atmosphere) = 5.158×1018 kg
* Kilogram (kg) is the SI base unit for mass
* Gram (g) = 1×10-3 kg
* Milligram (mg) = 1×10-6 kg
Universe Sandbox Wiki

Welcome to the Official Universe Sandbox Wiki, the Official Universe Sandbox reference written and maintained by the players.

Universe Sandbox is a physics-based space simulator that allows you to create, destroy, and interact on an unimaginable scale.

It merges real-time gravity, climate, collision, and materials interactions to reveal the beauty of our universe and the fragility of our planet. Universe Sandbox is the long-awaited sequel to the original Universe Sandbox Legacy.

[Read more...]

### Helping out

How to help
See how you can help contribute to Universe Sandbox Wiki! Remember to maintain a standard for grammar and punctuation in your contributions, please.
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### Guides

* Getting Started
* Interface
* Object Types
* VR
* Support
* About

### Object Properties

* Overview
* Motion
* Composition
* Surface
* Temperature
* Visuals
* Actions
* Galaxy
* Nebula
* Nova
* Barycenter

### Simulated Science

* Gravity
	+ N-Body Simulation
	+ Roche Fragmentation
	+ Spin Fragmentation
* Collisions
	+ Collision Simulation
	+ Momentum Conservation
	+ Mass Conservation
	+ Collision Fragmentation
	+ Friction Fragmentation
* Heating
	+ Temperature Calculations
	+ Collision Heating
	+ Tidal Heating
	+ Evaporation
* Surface Simulation
	+ Lasers

* Composition
	+ Materials
	+ Magnetic Fields
	+ Atmospheres
	+ Life Simulation
* Stars
	+ Stellar Evolution
	+ Supernova
	+ Stellar Wind
	+ Stellar Prominence
	+ Habitable Zone
* Galaxies
	+ Galaxy Structure
	+ Galaxy Types
	+ Galaxy Nebula Evolution

### Twitter

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