Authors:
Fulle, Marco; Blum, J.; Green, S. F.; Gundlach, B.; Herique, A.; Moreno, F.; Mottola, S.; Rotundi, A.; Snodgrass, C.
Journal:
Monthly Notices of the Royal Astronomical Society
Abstract:
We review the complex relationship between the dust-to-gas mass ratio usually estimated in the material lost by comets, and the refractory-to-ice mass ratio inside the nucleus, which constrains the origin of comets. Such a relationship is dominated by the mass transfer from the perihelion erosion to fallout over most of the nucleus surface. This makes the refractory-to-ice mass ratio inside the nucleus up to 10 times larger than the dust-to-gas mass ratio in the lost material, because the lost material is missing most of the refractories which were inside the pristine nucleus before the erosion. We review the refractory-to-ice mass ratios available for the comet nuclei visited by space missions, and for the Kuiper Belt Objects with well-defined bulk density, finding the 1-σ lower limit of 3. Therefore, comets and KBOs may have less water than CI-chondrites, as predicted by models of comet formation by the gravitational collapse of cm-sized pebbles driven by streaming instabilities in the protoplanetary disc.
URL:
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85059857798&doi=10.1093%2fmnras%2fsty2926&partnerID=40&md5=9ba255164fa844b543ce73e9eb836b93
Keywords:
space vehicles; comets: general; comets: individual: 67P/Churyumov-Gerasimenko; Kuiper belt: general; protoplanetary discs