Millions of years prior to the present day, Jove was a planet in between two suns. One of these suns is bigger and stronger than the other, and so the planet slowly has been being pulled towards it. Orbiting this larger sun are 42 planets. Jove is studded with these planets on its own surface, and orbits the larger sun.
Jove has a tripartite atmosphere, consisting of a layer of air, followed by a layer of ozone, followed by a layer of volcanic gas emissions. This causes extreme lightning storms when the two layers mix, which happens from time to time. In the 3rd layer, there are denizens from other planets that exist and are trapped in this atmosphere. They fight and die, and their corpses fall to earth.
Jove has 42 gods. Originally there were 43, but during the absorption of the other planets the God of Life was destroyed, although its corpse lives on. The other 42 gods are the sentient manifestations of forces in the universe, and every planet contains one of them. These 42 gods reside on the surface of Jove, although they are severely weakened following the Immortal War.
Jove has been partially terraformed as a result of the Ark Project's influence on the surface. Each Ark, sent from Earth with the remains of the planet's population, was supposed to terraform part of the planet. It was hoped that the Arks would be able to terraform the majority of the planet before they became too destroyed, but most of the Arks were destroyed on contact with the planet and so weren't able to terraform. The planet's own conditions are not inhospitable to humans, but following the destruction of the God of Life the planet has an abundance of unusual flora and fauna, as well as beings that don't easily fall into classifiable kingdoms. These include other sentient beings, as well as other ones.
Jove is the site of many anomalies and abnormal physical properties, due to the influence of it's Gods as well as the unusual formation of the planet. For example, the planet only has 1 pole, the North Pole, which is in the South as well (the place exists in 2 places at the same time). At the North Pole there is a mountain, with an Ark at it's peak. However, this peak is in the volcanic atmosphere, and is surrounded by intense radiation.
There are rivers, mountains, forests, etc on Jove. Most landscapes are simply far bigger than on Earth, although the continent boundaries can form anomalies and strange occurrences. There are multiple seas, which have their own seascapes.
See more about the Geology of Jove.