Every January marks the anniversary of the discovery of the two largest moons of Uranus.
German born British astronomer Friedrich Wilhelm (Frederick William) Herschel [1738-1822] had discovered the planet Uranus on 13 March 1781, at first mistaking it for a comet. On 11 January 1787, Herschel discovered both Titania and Oberon, the first Uranian moons to be discovered. The two moons are named after the Queen (Titania) and King (Oberon) of the mythical fairies in Shakespeare's "A Midsummer Night's Dream", and were named by William's son, John Herschel [1792-1871], in 1852.
Three more moons were discovered in 1851, two more in 1948, and ten more by the Voyager II science team. Uranus is now known to have 27 moons, the remaining twelve discovered post-Voyager (see the JPL link below).
The pictures of Titania & Oberon are both dated in January 1986, and both returned by Voyager II. No spacecraft has visited Uranus since then.
The two images of Uranus were made in 2004, by one of the two 10-meter Keck telescopes, observing at near infrared wavelength, with adaptive optics. They are more detailed than anything returned by Voyager, which could not image at infrared wavelengths. The rings are not visible, but there is a grey circle on the images, to show where the rings would be, if you could see them. The images show two opposite hemispheres of Uranus.
https://en.wikipedia.org/wiki/William_Herschel (William Herschel - Wikipedia)
https://en.wikipedia.org/wiki/Uranus (Uranus - Wikipedia)
https://en.wikipedia.org/wiki/Titania_(moon) (Titania, moon of Uranus - Wikipedia)
https://en.wikipedia.org/wiki/Oberon_(moon) (Oberon, moon of Uranus - Wikipedia)
https://ssd.jpl.nasa.gov/sats/discovery.html (Planetary Satellite Discovery Circumstances - JPL Small Body Database)
https://ssd.jpl.nasa.gov/sats/phys_par/ (Planetary Satellite Physical Parameters - JPL Small Body Database)
https://ssd.jpl.nasa.gov/sats/discovery.html (Planetary Satellite Discovery Circumstances - JPL Small Body Database)
https://science.nasa.gov/image-detail/amf-pia17306/ (Uranus images source - NASA)
https://photojournal.jpl.nasa.gov/catalog/PIA00036 (Titania image source - JPL Photojournal)
https://photojournal.jpl.nasa.gov/catalog/PIA00034 (Oberon image source - JPL Photojournal)
Reposted with permission from Tim Thompson, Retired NASA JPL Senior Astronomer
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