Themisto (muin)

Themisto (frae Greek: Θεμιστώ), an aa kent as Jupiter XVIII, is a smaw prograde irregular satellite o Jupiter. It wis discovered in 1975, subsequently lost, an rediscovered in 2000.

S 2000 J 1.jpg
Discovered biCharles Kowal (1975)

Elizabeth Roemer (1975)
Scott S. Sheppard (2000)
David C. Jewitt (2000)
Yanga R. Fernández (2000)

Eugene A. Magnier (2000)
Discovery dateSeptember 30, 1975
November 21, 2000 rediscovered
AdjectivesThemistoan, Themistonian
Orbital chairactereestics
Periapsis5,909,000 km (0.039 AU)
Apoapsis8,874,300 km (0.059 AU)
Mean orbit radius
7,391,650 km (0.04941 AU)
129.82761 d (0.3554 a)
4.098 km/s
Inclination45.81° (tae the ecliptic)
47.48° (tae Jupiter's equator)
Satellite oJupiter
Pheesical chairacteristics
Mean radius
4 km[1]
Circumference~25 km
~200 km2
Vollum~270 km3
Mass6.89×1014 kg
Mean density
2.6 g/cm3 (assumed)[2]
Albedo0.04 (assumed)[1]
Temperatur~124 K


  1. 1.0 1.1 Sheppard, S. S.; Jewitt, D. C.; An abundant population of small irregular satellites around Jupiter, Nature, 423 (May 15, 2003), pp. 261–263
  2. "Planetary Satellite Physical Parameters". JPL.