The article covering Jupiter's largest moon Ganymede is today's featured article over at Wikipedia. This is the third moon of Jupiter to be the featured article on Wikipedia's front page, the last being Europa back in February 2009. TFA highlights an article each day that has been recognized as a featured article on Wikipedia. These articles exemplify the best work on the website, meeting requirements such as extensive referencing (for verifiability), comprehensiveness, and stability. Additional Jupiter system articles that have been recognized as featured articles include the article on Io, Volcanism on Io, the Rings of Jupiter, the Magnetosphere of Jupiter, Callisto, the Atmosphere of Jupiter, and Jupiter itself.
Of course I couldn't help but get into an edit war on the Ganymede article over the discovery date of Ganymede, which is January 7.
Link: Wikipedia | Ganymede (moon) [en.wikipedia.org]