Mab (moon)

Mab, or Uranus XXVI,<ref name="Gazetteer" /> is an inner satellite of Uranus. It was discovered by Mark R. Showalter and Jack J. Lissauer in 2003 using the Hubble Space Telescope.<ref name="IAUC 8209" /> It was named after Queen Mab, a fairy queen from English folklore who is mentioned in William Shakespeare's play Romeo and Juliet.<ref name="Gazetteer" />

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.<ref name="Showalter Lissauer 2006" /> Following its discovery, Mab was given the temporary designation S/2003 U 1.<ref name="IAUC 8209" />

The size of Mab is not precisely known and has not been measured, so it is inferred by assuming the albedo to be similar to that of one of Mab's neighbouring moons, those being Puck and Miranda. If it is as dark as Puck, it would be about Template:Cvt in diameter.Template:Refn 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.<ref name="Showalter Lissauer 2006" /> Infrared observations published in 2023 suggest that Mab is probably a Template:Cvt diameter body with a brighter, Miranda-like surface that is rich in water ice; though not leaving out the possibility of it being a Template:Cvt diameter body with a dark, Puck-like surface.<ref name="Molter2023"/>

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.<ref name="Showalter Lissauer 2006" />

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.<ref name="Layton 2005" /> No rings associated with Perdita and Cupid have been found, probably because Belinda limits the lifetimes of dust they generate.<ref name="Showalter Lissauer 2006" />

See also

• Moons of Uranus

External links

• Hubble Uncovers Smallest Moons Yet Seen Around Uranus – Hubble Space Telescope news release (25 September 2003)
• NASA's Hubble Discovers New Rings and Moons Around Uranus – Hubble Space Telescope news release (22 December 2005)
• Hubble detects two large outer rings, two new moons orbiting Uranus (Courtesy of Astronomy Magazine 2005)