Oceanus. Artwork of the hypothetical planet Oceanus, which was predicted to lie beyond the edge of the known solar system. Here it is comprised mainly of swirling gas, & has a ring of ice grains & dust. Oceanus was one of three planets whose existence was predicted by Thomas Jefferson Jackson See in 1900-05. He made his predictions by studying the perturbations in the orbits of known planets. He calculated that Oceanus was a large planet that orbited the Sun once every 272 years at a distance that is 41.25 times further out than Earth's orbit. Extensive searches have failed to find such a planet, and it is unlikely to exist.