15 June 2017:
Two new moons were announced on 2 June 2017, and 5 June 2017. These moons, provisionally named S/2016 J 1 and S/2017 J 1, were discovered on 8 March 2016 and 23 March 2017, respectively. The announcements only came out this month because the International Astronomical Union insists on confirmation that a new body actually exists, by other astronomers, before going public. It took so long to verify their existence because these moons are absolutely tiny, at probably no more than 2km across. Incidentally, astronomers have actually lost some of the earlier moons. They’re tiny, so they’re easily buffeted by the gravity of other passing objects, and they’re hard to see so we don’t always spot when that happens!
18 July 2018
A group of astronomers searching for a 9th planet, predicted to have a highly elliptical orbit way out beyond that of Pluto, happened to have Jupiter drift through the area of sky they were studying. They didn’t find the elusive world, but did stumble upon a batch of new moons orbiting Jupiter, bringing the total up to 79.