New image shows 200 mile-long liquid river on Titan Evan AckermanWednesday, December 12, 2012 Planetary scientists have suspected for quite a while that Titan, one of Saturn's moons, has a 'methane cycle' that's much like the water cycle we have here on Earth. New pictures from Cassini suggests that the similarity between Titan and Earth may be even more pronounced, as astronomers have identified a huge, Earth-like river system full of liquid methane.
The giant orange moon Titan — larger than the planet Mercury — can be seen at upper right. The white icy moons that are much closer to Saturn, hence much closer to the ring plane in this view, are, from left to right: Enceladus, Dione, and Mimas. The dark band running across the face of the planet slightly above the rings is the shadow of the rings cast on the planet
Like the sun, Jupiter is composed predominantly of hydrogen & helium. But unlike the sun, it lacks the necessary amount to begin fusion, the process that fuels a star. Jupiter would need to be 75-80 times more massive than it is at present to be considered a star. If all of the planets in the solar system had formed as part of the gas giant, it still would not have sufficient mass. Still, by itself, Jupiter is 2 & 1/2 times larger than all of the other planets in the solar system combined.
Saturn’s south polar vortex- A monstrous vortex sits at Saturn’s south pole. It’s not just beautiful. It also lets astronomers peer deep into Saturn’s dense atmosphere: NASA/JPL/Space Science Institute