New gravity field of comet 67P/C-G based on Rosetta's Doppler and optical data

TL;DR

This paper presents a detailed gravity model of comet 67P/C-G derived from Rosetta's Doppler and optical data, revealing mass heterogeneity, mass loss, and center of gravity shifts due to sublimation.

Contribution

It provides the first degree 4 gravity field of the comet and quantifies mass loss and center of gravity shifts with high precision.

Findings

Detected mass heterogeneity in the nucleus.

Estimated mass loss at 0.28% of total mass.

Measured a 35 m shift in the center of gravity.

Abstract

We provide a new gravity field of Comet 67P-C/G up to degree 4. We detect mass heterogeneity in the comet nucleus. The loss of mass is restimated at 0.28\% of the comet's total mass (3 times larger than previous estimate). Comparison of the gravity field between pre- and post-perihelion allowed us to measure a shift in the comet's center of gravity of 35 m northward, attributed to ice sublimation process.