Martian soil perchlorate readings being caused by terrestrial sources, which at the time were thought could have migrated from the spacecraft either into samples or the instrumentation. However, each new lander has confirmed their presence in the soil locally and the "Mars Odyssey" orbiter confirmed they are spread globally across the entire surface of the planet. While our understanding of Martian soils is extremely rudimentary, their diversity may raise the question of how we might compare them with our Earth-based soils. Applying an Earth-based system is largely debatable but a simple option is to distinguish the (largely) biotic Earth from the abiotic
Giant planet with Jupiter than with the other giant planets, some have claimed that "jovian planet" is a more accurate term for them. Many of the exoplanets are much closer to their parent stars and hence much hotter than the giant planets in the Solar System, making it possible that some of those planets are a type not observed in the Solar System. Considering the relative abundances of the elements in the universe (approximately 98% hydrogen and helium) it would be surprising to find a predominantly rocky planet more massive than Jupiter. On the other hand, models of planetary-system formation have suggested