Adrastea (moon) No surface details of Adrastea are known, due to the low resolution of available images. Adrastea is the smallest and second-closest member of the inner Jovian satellite family. It orbits Jupiter at a radius of about 129,000 km (1.806 Jupiter radii) at the exterior edge of the planet's Main Ring. Adrastea is one of only three moons in the Solar System known to orbit its planet in less than the length of that planet's day—the other two being Jupiter's innermost moon Metis, and Mars' moon Phobos. The orbit has very small eccentricity and inclination—around 0.0015 and 0.03°, respectively. Inclination is
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