Leda (moon)

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Leda
Discovery
Discovered by Charles T. Kowal
Discovery time September 11, 1974[1]
Orbit
Avgdistance from the center of its orbital path 11,160,000 km[2]
How egg-shaped its orbit is
("eccentricity")
0.16[2]
How long it takes to complete an orbit 240.92 d (0.654 a)[2]
Average speed 3.4 km/s
Angle above the reference plane
("inclination")
27.46° (to the ecliptic)
29.01° (to Jupiter's equator)[2]
What it orbits Jupiter
Size and Other Qualities
Average distance from its center to its surface 10 km
Area of its surface ~1250 km²
Volume inside it ~4200 km³
Mass 1.1×1016 kg
Average density 2.6 g/cm³ (assumed)
Gravity at its surface ~0.0073 m/s2 (0.001 g)
Slowest speed able to escape into space
("escape velocity")
~0.012 km/s
How much light it reflects 0.04 (assumed)
Avg. surface temp. ~124 K
Seeming brightness
("apparent magnitude")
20.2 [3]

Leda or Jupiter XIII, is a prograde non-spherical moon of Jupiter. It was found 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).[1][4] 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 supported it in 1975.[5]

Leda belongs to the Himalia group, five moons orbiting between 11,000,000 and 13,000,000 km from Jupiter at an inclination of about 27.5°.[2] The orbital elements given here are as of January 2000, but they are changing a lot due to Solar and planetary perturbations.

References[change | edit source]

  1. 1.0 1.1 Kowal, C. T.; Aksnes, K.; Marsden, B. G.; and Roemer, E. (1974). "Thirteenth satellite of Jupiter". Astronomical Journal 80: pp. 460–464. http://adsabs.harvard.edu//full/seri/AJ.../0080//0000460.000.html.
  2. 2.0 2.1 2.2 2.3 2.4 Jacobson, R. A. (2000). "The orbits of outer Jovian satellites". Astronomical Journal 120: pp. 2679-2686. doi:10.1086/316817.
  3. "Leda Statistics". http://www.solarviews.com/eng/leda.htm. Retrieved 2007-10-01.
  4. IAUC 2702: Probable New Satellite of Jupiter 1974 September 20 (discovery)
  5. Marsden, B. G. (7 October 1974). "Satellites of Jupiter". IAUC Circular 2846. http://cfa-www.harvard.edu/iauc/02800/02846.html.

Other websites[change | edit source]