|Discovered by||Charles T. Kowal|
|Discovery date||September 11, 1974|
Mean orbit radius
|240.92 d (0.654 a)|
Average orbital speed
|Inclination||27.46° (to the ecliptic)|
29.01° (to Jupiter's equator)
|2.6 g/cm3 (assumed)|
|~0.0073 m/s2 (0.001 g)|
Leda (// LEE-də; Greek: Λήδα), also known as Jupiter XIII, is a prograde irregular satellite of Jupiter. It was discovered by Charles T. Kowal at the Mount Palomar Observatory on September 14, 1974, after three nights' worth of photographic plates had been taken (September 11 through 13; Leda appears on all of them). It was named after Leda, who was a lover of Zeus, the Greek equivalent of Jupiter (who came to her in the form of a swan). Kowal suggested the name and the IAU endorsed it in 1975.
Leda belongs to the Himalia group, five moons orbiting between 11 and 13 Gm from Jupiter at an inclination of about 27.5°. The orbital elements given here are as of January 2000, but they are continuously changing due to solar and planetary perturbations.
- The 1956 British film Fire Maidens from Outer Space was set on Jupiter's 13th moon, although this film was made before the discovery of Leda in 1974.
- In Brenda Hiatt's 2013 teen, science fiction themed romance novel, Starstruck, Rigel impresses Marsha with a telescope that clearly sees Leda. Rigel is in turn impressed that Marsha knows so much about the obscure moon of Jupiter, to include that it was not even discovered until 1974.
- In Liu Cixin's 2010 science fiction novel Death's End, Jupiter XIII is consumed by a man-made blackhole, thus creating the first-ever stable man-made blackhole.
- Kowal, C. T.; Aksnes, K.; Marsden, B. G.; Roemer, E. (1974). "Thirteenth satellite of Jupiter". Astronomical Journal. 80: 460–464. Bibcode:1975AJ.....80..460K. doi:10.1086/111766.
- Jacobson, R. A. (2000). "The orbits of outer Jovian satellites" (PDF). Astronomical Journal. 120 (5): 2679. Bibcode:2000AJ....120.2679J. doi:10.1086/316817.
- Calvin J. Hamilton (1997–2009). "Leda Statistics". Views of the Solar System. Retrieved October 1, 2007.
- Brian G. Marsden (September 20, 1974). "IAUC 2702: Probable New Satellite of Jupiter". International Astronomical Union.
- Marsden, Brian G. (October 7, 1975). "Satellites of Jupiter". International Astronomical Union.