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
Phaeton (hypothetical planet) the protoplanetary disk, and in this region the incorporation of protoplanetary remnants into the planets was prevented by large gravitational perturbations induced by Jupiter during the formative period of the solar system. Some scientists and non-scientists continue to advocate for the existence and destruction of a Phaeton-like planet. Zecharia Sitchin suggested that the goddess known to the Sumerians as Tiamat in fact relates to a planet that was destroyed by a rogue planet known as Nibiru, creating both Earth and the asteroid belt. His work is widely regarded as pseudoscience. The astronomer and author Tom Van Flandern held that Phaeton