Saturn , Nasa probe . 土星 ， NASA探測器 。

Mysteries of Saturn revealed: Nasa probe captures clearest views of planet's rings - and the tiny 'mini-moons' swimming inside them | Mail Online http://www.dailymail.co.uk/sciencetech/article-2174882/Mysteries-Saturn-revealed-Nasa-probe-captures-clearest-views-planets-rings--tiny-mini-moons-swimming-inside-them.html