Mab (moon)

Mab
Discovery
Discovered byMark R. Showalter and Jack J. Lissauer
Discovery dateAugust 25, 2003
Designations
Designation
Uranus XXVI
Pronunciation/ˈmæb/[1]
AdjectivesMabian[2]
Orbital characteristics[3]
97 736 km
Eccentricity0.00347
0.923 d
7.70 km/s (calculated)
Inclination0.12217° (to Uranus' equator)
Satellite ofUranus
Physical characteristics
6 km/12.4±0.5 km
~450/1930 km2
Volume~900/7990 km3
Mass~(0.90/8.0)×1015 kg
Mean density
0.5–1.2 g/cm3[4]
1 g/cm3 (assumed)
~0.002/0.003 m/s2
~0.004/0.009 km/s
synchronous
0
Albedo~0.46/0.1 (assumed)[5]
Temperature~63 K
26[6]

Mab, or Uranus XXVI,[7] is an inner satellite of Uranus. It was discovered by Mark R. Showalter and Jack J. Lissauer in 2003 using the Hubble Space Telescope.[8] It was named after Queen Mab, a fairy queen from English folklore who is mentioned in William Shakespeare's play Romeo and Juliet.[7]

Because the moon is small and dark, it was not seen in the heavily scrutinized images taken by Voyager 2 during its Uranus flyby in 1986. However, it is brighter than another moon, Perdita, which was discovered from Voyager's photos in 1997. This led scientists to re-examine the old photos again, and the satellite was finally found in the images.[9] Following its discovery, Mab was given the temporary designation S/2003 U 1.[8]

The size of Mab is not precisely known. If it is as dark as Puck, it is about 24.8±1.0 km in diameter.[11] On the other hand, if it has a relatively bright surface like the neighbouring moon Miranda, it would be smaller than Cupid and comparable to the smallest outer satellites.[9] Infrared observation published in 2023 suggest that Mab is probably a 12-km body with a Miranda-like surface, rich in water ice; though not leaving out the possibility of it being a 24-km body with a Puck-like surface.[5]

Mab is heavily perturbed. The actual source for perturbation is still unclear, but is presumed to be one or more of the nearby orbiting moons.[9]

Mab orbits at the same distance from Uranus as the μ ring (formerly known as R/2003 U 1), a dusty ring discovered around the same time as Mab. The moon is nearly the optimal size for dust production, since larger moons can recollect the escaping dust and smaller moons have too small surface areas for supplying the ring via ring particle or meteoroid collisions.[12] No rings associated with Perdita and Cupid have been found, probably because Belinda limits the lifetimes of dust they generate.[9]

  1. ^ "Mab". Dictionary.com Unabridged (Online). n.d.
  2. ^ Richard Allen Isomaki (1986) Shelley's Causal Themes. PhD thesis, University of Washington.
  3. ^ Cite error: The named reference ĆukEtAl2022 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference French & Showalter 2012 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Molter2023 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Sheppard urasatdata was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Gazetteer was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference IAUC 8209 was invoked but never defined (see the help page).
  9. ^ a b c d e Cite error: The named reference Showalter Lissauer 2006 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Ćuk et al. 2022 was invoked but never defined (see the help page).
  11. ^ Showalter & Lissauer (2006),[9] as cited in Ćuk et al. (2022).[10]
  12. ^ Cite error: The named reference Layton 2005 was invoked but never defined (see the help page).