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
Planet Nine cause the orbits of the other planets to precess, similar to but slower than the eTNOs, covering short arcs over the lifetime of the Solar System. These observations are consistent with the Planet Nine hypothesis but do not prove that Planet Nine exists as there are other potential explanations for the spin–orbit misalignment of the Solar System. Batygin was cautious in interpreting the results of the simulation developed for his and Brown's research article, saying, "Until Planet Nine is caught on camera it does not count as being real. All we have now is an echo." Brown put the odds