Lately, this question has had a changing answer! For many years, we knew of 16 moons for the largest planet in our solar system. In the last few years, about two dozen new moons have been announced by astronomers I. However, being announced does not mean that these become "official" moons of the planet. To be recognized by the scientific community as a new moon involves a process which may take several years - and some announced objects never get recognized at all! Let's explain.
When a scientist makes observations which indicate a new moon, they submit their data and analysis to the scientific community.