Prospero (moon)


Prospero is a relatively small retrograde irregular satellite of Uranus discovered on 18 July 1999 by the astrophysicist Matthew Holman and his team, and given the provisional designation S/1999 U 3. Confirmed as Uranus XVIII it was named after the sorcerer Prospero in William Shakespeare's play The Tempest.

Prospero - Uranus moon.jpg
Discovery image of Prospero, taken by the CFHT in July 1999
Discovered by
Discovery date18 July 1999
Uranus XVIII
AdjectivesProsperonian /prɒspɛˈrniən/,[2] Prosperian /prɒˈspɪəriən/[3]
Orbital characteristics
Mean orbit radius
16,256,000 km[4][5]
1978.29 d
Inclination152°[4] (to the ecliptic)[4]
Satellite ofUranus
Physical characteristics
Mean radius
25 km (estimate)[6]
~8000 km2 (estimate)
Volume~65,000 km3 (estimate)
Mass~8.5×1016 kg (estimate)
Mean density
~1.3 g/cm3 (assumed)
~0.0063 m/s2 (estimate)
~0.021 km/s (estimate)
7.145 h
Albedo0.04 (assumed)[6]
Temperature~65 K (estimate)
Animation of discovery images to show Prospero's motion among background stars

The orbital parameters suggest that it may belong to the same dynamic cluster as Sycorax and Setebos, suggesting common origin.[7] However, this suggestion does not appear to be supported by the observed colours. The satellite appears neutral (grey) in visible light (colour indices B-V=0.80, R-V=0.39),[8] similar to Setebos but different from Sycorax (which is light red).

See alsoEdit


  1. ^ Benjamin Smith (1903), The Century Dictionary and Cyclopedia
  2. ^ Emenyonu, Ernest (2003), Emerging perspectives on Chinua Achebe, v. 1.
  3. ^ in scare quotes in Bate (1997) The genius of Shakespeare
  4. ^ a b c Sheppard, Jewitt & Kleyna 2005, p. 523, Table 3.
  5. ^ a b Yeomans, Donald K. (28 June 2007). "Planetary Satellite Mean Orbital Parameters". JPL/NASA. Retrieved 19 January 2008.
  6. ^ a b Sheppard, Jewitt & Kleyna 2005, p. 523, Table 3 ... ri (km) ... 25 ... i Radius of satellite assuming a geometric albedo of 0.04.
  7. ^ Grav, Tommy; Holman, Matthew J.; Gladman, Brett J.; Aksnes, Kaare Photometric survey of the irregular satellites, Icarus, 166, (2003), pp. 33–45. arXiv:astro-ph/0301016
  8. ^ Grav, Holman & Fraser 2004.

External linksEdit

  • Prospero Profile by NASA's Solar System Exploration
  • David Jewitt pages
  • Uranus' Known Satellites (by Scott S. Sheppard)
  • MPC: Natural Satellites Ephemeris Service