The moon of Jupiter – Carme (XI) – was discovered in
1938 by S. Nicholson. It is one four moons discovered by this astronomer, since the discovery came 24 years after he discovered Sinope.
In the same year he discovered Lysithea. Some time later he also discovered
Ananke.
The name of that moon is of mythological origin. Carme was a nymph and attendant of Artemis; mother, by Zeus, of Britomartis (Cretan
idols)...
The moon by this name
is in elliptical retrograde orbit
(→eccentricity
e = 0.2533) with a →semimajor axis a = 23,404,000 km. At pericenter (closest to the planet) Carme is separated from the Jupiter a distance of q = 17,475,767 km. At apocenter (furthest from the planet) this moon is separated from the Jupiter a distance of Q = 29,332,233 km.
In future these parameters may vary due to a large orbital distance from Jupiter and the orbital motion being disturbed by the Sun and other factors. Perhaps it is a captured asteroid (with a diminutive mass: ~1.3188×1017 kg – it equals
almost 18 mountains like Giewont
!),
and in future will possibly return to heliocentric orbit.
The orbital period is over 2 earthly years, which means that the average speed of its celestial motion is
only 0°29'25'' per day. When this motion was detected and compared to the changes in Jupiter's position, this body was classified as a true planetary satellite (and not a distant celestial body with its position projected near the planet).
Other obstacle in detecting this moon earlier was its brightness of only 17.6m
(almost 43.7 thousand times fainter than the faintest stars visible to naked eye). For comparison: Jupiter's brightness is about
–2.7m,
so Carme is shining fainter by about 20.3m.
The corresponding difference in brightness is almost 132 million times!
I have given some crucial data of Carme below. Table one
contains the basic information. Whereas table two gives more detailed parametrs
of its orbit (calculated using the following formulae).
Translated by Karol Pankowski
|
Carme
|
|---|
| Mean distance from the planet [×103 km] |
23,404.0
|
| Mean distance from the planet [planetary R] |
327.4
|
| Orbital period [days] |
734.17
|
| Orbital eccentricity [e] |
0.2533
|
| Orbit inclination [degrees] |
164.9
|
| Mean diameter [km] |
46.0
|
| Main discoverer and year of the discovery |
S. Nicholson 1938
|
| Visual magnitude [mag] |
17.6
|
| Mass [kg] |
~1.3188 × 1017
|
Orbital Parameters |
Pericenter
[q] |
Apocenter
[Q] |
| Distance from the planet [×103 km] |
17,475.8
|
29,332.2
|
| Distance from the planet [planetary R] |
244.4
|
410.3
|
| Angular size of the moon's orbit observed from the Earth* [degrees] |
1°35'33.67''
|
2°40'25.94''
|
|
| Angular diameter of the planet's disc as observed from the moon [degrees] |
0°28'07.63''
|
0°16'45.47''
|
| Brightness of the planet as observed from the moon** [mag] |
–10.5
|
–9.4
|
| Diameter of the moon's disc as observed from the planet's "surface" [degrees] |
0°00'00.55''
|
0°00'00.32''
|
| Brightness of the moon as observed from the planet's "surface"** [mag] |
9.8
|
10.9
|
|
Orbital velocity [km/sec] |
3.01
|
1.80
|
* This value is calculated for Jupiter at opposition (distance 628.8 million km = 4.2 AU)
** The given value of magnitude is not corrected for some decreasing factors (e.g. the changing phase of illumination)
|
See other related links:
Astronomy for every – Jupiter's moons
Monde
des Monats
– CARMEGRUPPE
Views
of the Solar System – CARME
Solar
System Exploration – CARME
The
Nine Planets – CARME
The Astronomy Workshop – Satellite Viewer
Planetary Satellite Mean Orbital Parameters
Natural Satellite Physical Parameters
