Constants#

Scarabaeus defines both physical constants and planetary constants, tabulated below. Additionally, the source code definitions and their references are available further down under API Reference.

Physical Constants#

Name

Value

Units

G

6.6743e-20

km^3/(kg*sec^2)

L_tilde_GR

1.480827e-08

unitless

Stefan_Boltzmann

5.670374419e-08

kg/sec^3

c

299792.458

km/sec

gamma_GR

1.0

unitless

srp_constant1

102115339416981.84

(kg*km)/sec^2

srp_constant2

101979437570000.0

(kg*km)/sec^2

Major Bodies#

Body

SPICE ID

Mass (kg)

GM (km³/s²)

Mean Radius (km)

Eq. Radius (km)

Primary

Sun

10

1.9884e+30

1.32712e+11

696000.0

—

—

Mercury

199

3.3010e+23

22031.8

2439.7

2441

—

Venus

299

4.8673e+24

324859

6051.8

6052

—

Earth

399

5.9722e+24

398600

6371.0084

6378

—

Mars

499

6.4169e+23

42828.4

3389.5

3396

—

Jupiter

599

1.8981e+27

1.26687e+08

69911.0

7.149e+04

—

Saturn

699

5.6832e+26

3.79312e+07

58232.0

6.027e+04

—

Uranus

799

8.6810e+25

5.79395e+06

25362.0

2.556e+04

—

Neptune

899

1.0241e+26

6.8351e+06

24622.0

2.476e+04

—

Minor Bodies#

Body

SPICE ID

Mass (kg)

GM (km³/s²)

Mean Radius (km)

Eq. Radius (km)

Primary

Scheeres

20008887

6.2400e+14

4.16e-05

3.907

—

SUN

Deimos

402

1.4407e+15

9.61557e-05

6.0

—

Mars

McMahon

20046829

4.2900e+13

2.86e-06

1.6

—

SUN

Justitia

20000269

1.0488e+17

0.007

50.728

—

SUN

Mattia Pugliatti

2042042

6.2928e+17

0.042

4.2

—

SUN

Moon

301

7.3458e+22

4902.8

1737.4

1738

Earth

Phobos

401

1.0619e+16

0.000708755

11.4

—

Mars

Pluto

999

1.3029e+22

869.614

1195.0

1195

—

API Reference#

class Constants#

Constant values defined within Scarabaeus.

Notes

Contains physical constants and planetary constants.

DANIEL_SCHEERES = PCInfo(name='Scheeres', spice_name='SCHEERES', ref_name=None, body_center_id=20008887, barycenter_id=None, mass=624000000000000.0 kg, GM=4.16e-05 mu, mean_radius=3.907 km, equatorial_radius=None, GM_barycenter=None, primary_body='SUN')#

Planetary constants and related information for asteroid (8887) Scheeres, given as PCInfo.

Named in honor of Prof. Daniel J. Scheeres (ORCCA, CU Boulder), pioneer of small-body gravitational dynamics and orbital mechanics. Mean radius from NEOWISE thermal survey (diameter 7.814 ± 0.071 km, albedo 0.187 ± 0.014). GM estimated from assumed S-type bulk density of 2500 kg/m³; no spacecraft measurement exists.

[1]

JPL Small-Body Database, https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=8887

DEIMOS = PCInfo(name='Deimos', spice_name='DEIMOS', ref_name='IAU_DEIMOS', body_center_id=402, barycenter_id=None, mass=1440685861906164.2 kg, GM=9.615569648120313e-05 mu, mean_radius=6.0 km, equatorial_radius=None, GM_barycenter=None, primary_body='Mars')#

Planetary constants and related information for Deimos, given as PCInfo.

EARTH = PCInfo(name='Earth', spice_name='EARTH', ref_name='ITRF93', body_center_id=399, barycenter_id=3, mass=5.972168398724898e+24 kg, GM=398600.435436096 mu, mean_radius=6371.0084 km, equatorial_radius=6378.1366 km, GM_barycenter=403503.23550226 mu, primary_body=None)#

Planetary constants and related information for Earth, given as PCInfo.

G = 6.6743e-20 km^3/(kg*sec^2)#

Universal gravitational constant.

JAY_MCMAHON = PCInfo(name='McMahon', spice_name='MCMAHON', ref_name=None, body_center_id=20046829, barycenter_id=None, mass=42900000000000.0 kg, GM=2.86e-06 mu, mean_radius=1.6 km, equatorial_radius=None, GM_barycenter=None, primary_body='SUN')#

Planetary constants and related information for asteroid (46829) McMahon, given as PCInfo.

Named in honor of Prof. Jay W. McMahon (ORCCA, CU Boulder), co-developer of Scarabaeus. A main-belt binary system (1998 OS14); the radius is estimated from absolute magnitude H = 15.10 assuming S-type albedo ~0.15. GM estimated from assumed bulk density of 2500 kg/m³; no spacecraft measurement exists.

[1]

JPL Small-Body Database, https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=46829

JUPITER = PCInfo(name='Jupiter', spice_name='JUPITER', ref_name='IAU_JUPITER', body_center_id=599, barycenter_id=5, mass=1.898124671078627e+27 kg, GM=126686534.92180079 mu, mean_radius=69911.0 km, equatorial_radius=71492.0 km, GM_barycenter=126712764.8 mu, primary_body=None)#

Planetary constants and related information for Jupiter, given as PCInfo.

JUSTITIA = PCInfo(name='Justitia', spice_name='JUSTITIA', ref_name=None, body_center_id=20000269, barycenter_id=None, mass=1.0487991250018728e+17 kg, GM=0.007 mu, mean_radius=50.728 km, equatorial_radius=None, GM_barycenter=None, primary_body='SUN')#

Planetary constants and related information for Justitia, given as PCInfo.

L_tilde_GR = 1.480827e-08 unitless#

L tilde constant for General Relativity.

MARS = PCInfo(name='Mars', spice_name='MARS', ref_name='IAU_MARS', body_center_id=499, barycenter_id=4, mass=6.416908682663213e+23 kg, GM=42828.37362069909 mu, mean_radius=3389.5 km, equatorial_radius=3396.19 km, GM_barycenter=42828.375214 mu, primary_body=None)#

Planetary constants and related information for Mars, given as PCInfo.

MATTIA_PUGLIATTI = PCInfo(name='Mattia Pugliatti', spice_name='MATTIA_PUGLIATTI', ref_name=None, body_center_id=2042042, barycenter_id=None, mass=6.292794750011237e+17 kg, GM=0.042 mu, mean_radius=4.2 km, equatorial_radius=None, GM_barycenter=None, primary_body='SUN')#

Planetary constants and related information for asteroid Mattia Pugliatti, given as PCInfo.

A fictitious S-type asteroid in the main belt, named in honor of Dr. Mattia Pugliatti (ORCCA, CU Boulder), co-developer of Scarabaeus. All physical parameters are suspiciously close to multiples of 42.

MERCURY = PCInfo(name='Mercury', spice_name='MERCURY', ref_name='IAU_MERCURY', body_center_id=199, barycenter_id=1, mass=3.300987369461969e+23 kg, GM=22031.78 mu, mean_radius=2439.7 km, equatorial_radius=2440.53 km, GM_barycenter=22031.78 mu, primary_body=None)#

Planetary constants and related information for Mercury, given as PCInfo.

MOON = PCInfo(name='Moon', spice_name='MOON', ref_name='IAU_MOON', body_center_id=301, barycenter_id=None, mass=7.345789170645305e+22 kg, GM=4902.8000661638 mu, mean_radius=1737.4 km, equatorial_radius=1738.14 km, GM_barycenter=None, primary_body='Earth')#

Planetary constants and related information for the Moon, given as PCInfo.

NEPTUNE = PCInfo(name='Neptune', spice_name='NEPTUNE', ref_name='IAU_NEPTUNE', body_center_id=899, barycenter_id=8, mass=1.0240923396370664e+26 kg, GM=6835099.502439672 mu, mean_radius=24622.0 km, equatorial_radius=24764.0 km, GM_barycenter=6836527.10058002 mu, primary_body=None)#

Planetary constants and related information for Neptune, given as PCInfo.

PHOBOS = PCInfo(name='Phobos', spice_name='PHOBOS', ref_name='IAU_PHOBOS', body_center_id=401, barycenter_id=None, mass=1.0619160161956238e+16 kg, GM=0.0007087546066894452 mu, mean_radius=11.4 km, equatorial_radius=None, GM_barycenter=None, primary_body='Mars')#

Planetary constants and related information for Phobos, given as PCInfo.

PLUTO = PCInfo(name='Pluto', spice_name='PLUTO', ref_name='IAU_PLUTO', body_center_id=999, barycenter_id=9, mass=1.3029288730816338e+22 kg, GM=869.6138177608749 mu, mean_radius=1195.0 km, equatorial_radius=1195.0 km, GM_barycenter=977.000000000001 mu, primary_body=None)#

Planetary constants and related information for Pluto, given as PCInfo.

SATURN = PCInfo(name='Saturn', spice_name='SATURN', ref_name='IAU_SATURN', body_center_id=699, barycenter_id=6, mass=5.683173890692993e+26 kg, GM=37931207.49865224 mu, mean_radius=58232.0 km, equatorial_radius=60268.0 km, GM_barycenter=37940585.2 mu, primary_body=None)#

Planetary constants and related information for Saturn, given as PCInfo.

SUN = PCInfo(name='Sun', spice_name='SUN', ref_name='IAU_SUN', body_center_id=10, barycenter_id=0, mass=1.9884098713264208e+30 kg, GM=132712440041.939 mu, mean_radius=696000.0 km, equatorial_radius=None, GM_barycenter=None, primary_body=None)#

Planetary constants and related information for the Sun, given as PCInfo. The mean and equatorial radii of the Sun are taken to be equivalent, and so only mean_radius is given.

Stefan_Boltzmann = 5.670374419e-08 kg/sec^3#

Stefan-Boltzmann constant.

Note that the units of the Stefan-Boltzmann constant are W/(m^2*K^4). ArrayWUnits does not support units of Kelvin (K), so the constant is returned in kg/s^3, or W/m^2, with the 1/K^4 omitted.

URANUS = PCInfo(name='Uranus', spice_name='URANUS', ref_name='IAU_URANUS', body_center_id=799, barycenter_id=7, mass=8.680987253013813e+25 kg, GM=5793951.322279009 mu, mean_radius=25362.0 km, equatorial_radius=25559.0 km, GM_barycenter=5794548.60000001 mu, primary_body=None)#

Planetary constants and related information for Uranus, given as PCInfo.

VENUS = PCInfo(name='Venus', spice_name='VENUS', ref_name='IAU_VENUS', body_center_id=299, barycenter_id=2, mass=4.867305814842005e+24 kg, GM=324858.592 mu, mean_radius=6051.8 km, equatorial_radius=6051.8 km, GM_barycenter=324858.592 mu, primary_body=None)#

Planetary constants and related information for Venus, given as PCInfo.

c = 299792.458 km/sec#

Speed of light in a vacuum.

gamma_GR = 1.0 unitless#

Gamma constant for General Relativity.

srp_constant1 = 102115339416981.84 (kg*km)/sec^2#

SRP Constant #1.

srp_constant2 = 101979437570000.0 (kg*km)/sec^2#

SRP Constant #2.