Pluto before Charon was discovered. Pluto is more than twice the diameter and a dozen times the mass of the dwarf planet Ceres, the largest object in the asteroid belt. It is less massive than the dwarf planet Eris, a trans-Neptunian object discovered in 2005, though Pluto has a larger diameter of 2376.6 km compared to Eris's approximate diameter of 2326 km. Determinations of Pluto's size had been complicated by its atmosphere, and hydrocarbon haze. In March 2014, Lellouch, de Bergh et al. published findings regarding methane mixing ratios in Pluto's atmosphere consistent with a Plutonian diameter greater than 2360 km,
Atmosphere of Pluto it was possible to calculate its distance from Pluto's center. Subtracting the modern figure for the radius of Pluto, the result is a height of ; hence this "haze" is indistinguishable from the surface of Pluto. During later occultations (when the atmosphere of Pluto was already denser) this kink was absent. Another evidence of the haze was obtained in 2002 due to a new occultation. The stellar light which managed to reach Earth during the occultation (due to refraction in Pluto's atmosphere), demonstrated an increase of intensity with wavelength. This was interpreted as a reliable evidence of light scattering by