| Mass (1023
kg) |
Mass of the body in 10^24 kilograms. |
| Volume (1010 km3) |
Volume of the body in 10^10 km^3. |
| Equatorial radius (km) |
Radius of the body at the equator
in kilometers. |
| Ellipticity (Flattening) |
The ratio (equatorial - polar
radius)/(equatorial radius), dimensionless. |
| Mean density
(kg/m3) |
Average density of the body
(mass/volume) in kilograms/(meter^3). |
| Surface gravity (m/s2) |
Effective equatorial gravitational
acceleration at the surface of the body or the 1 bar level, including
the effects of rotation, in meters/(second^2). |
| Escape velocity (km/s) |
Initial velocity required to
escape the body's gravitational pull in kilometers/second. |
| GM (x 106 km3/s2) |
Gravitational constant times the
mass of the body in 10^6 kilometers^3/seconds^2. |
| Mean distance from the Sun (km) |
Mean distance from the Sun in 10^6
kilometers. |
| Rotational period (days/hrs) |
The time for one rotation of the
body on its axis relative to the fixed
stars, in hours. A minus
sign indicates retrograde rotation. |
| Orbital period (days) |
The time it takes the body to make
one revolution about the Sun relative to the fixed stars in days. |
| Mean orbital velocity (km/s) |
The average speed of the body in orbit, in kilometers/second. |
| Orbit eccentricity |
A measure of the circularity of
the orbit, equal to (aphelion -
perihelion distance)/(2 x
semi-major
axis). |
| Tilt of axis (degrees) |
The tilt of the body's equator
relative to the body's orbital plane, in degrees. |
| Orbit inclination (degrees) |
The inclination of the orbit to
the ecliptic, in degrees. |
| Bond albedo |
The fraction of incident solar
radiation reflected back into space without absorption, dimensionless.
Also called planetary albedo. |
| Visual geometric albedo |
The ratio of the body's brightness
at a phase angle of zero to the brightness of a perfectly diffusing disk
with the same position and apparent size, dimensionless. |
| Visual magnitude V(1,0) |
The visual magnitude of the body
if it were one AU (1.496 x 10^8
kilometers) from the Earth at a
phase angle of zero, dimensionless. |
| Solar irradiance (W/m2) |
Solar energy on the body in
Watts/(meter^2). |
| Moment of inertia (I/MR2) |
The moment of inertia of the body
expressed as the rotational inertia divided by the body's (mass x
radius^2). A hollow spherical shell has a moment of inertia of
2/3, a homogeneous sphere 0.4. |
| J2 (x 10-6) |
The ratio of the difference in the
moments of inertia to the mass of the body times the radius^2, (C-A)/(M
R^2), x 10^-6, dimensionless. |
| Mean surface temperature |
Mean temperature of the body over
the entire surface in degrees Celsius and Kelvin. |
| Maximum surface temperature |
Maximum temperature of the body
over the entire surface in degrees Celsius and Kelvin. |
| Minimum surface temperature |
Minimum temperature of the body
over the entire surface in degrees Celsius and Kelvin. |
| Atmospheric composition/Trace
amounts of |
Relative volume of constituents in
the atmosphere, by percentage or ppm (parts per million). |
