Neptune’s Moon Triton: Continuing Surface Seasonal Volatile Transport

Abstract

Observations of Triton’s rotational light curve from Table Mountain Observatory in 2017 show that volatile transport is continuing on its surface. Changes in the light curve are consistent with sustained increases in albedo in two patches near the equator at longitudes of ∼120° and ∼280°, as first reported by Bauer et al. based on observations obtained with the Hubble Space Telescope. An early observation of Triton’s visual albedo shows a substantially lower albedo in the past, when the northern polar region was visible. This result confirms the hypothesis of Moore & Spencer and Spencer & Moore of a net flux of volatile material into the southern hemisphere of Triton over much of the satellite’s history and up to the present. The averaged V-band geometric albedo of Triton has been stable over the past three decades. The color of Triton has also been stable during the past decade.