Heterogeneous mass distribution of the rubble-pile asteroid (101955) Bennu.
Sci Adv
; 6(41)2020 Oct.
Article
em En
| MEDLINE
| ID: mdl-33033036
ABSTRACT
The gravity field of a small body provides insight into its internal mass distribution. We used two approaches to measure the gravity field of the rubble-pile asteroid (101955) Bennu (i) tracking and modeling the spacecraft in orbit about the asteroid and (ii) tracking and modeling pebble-sized particles naturally ejected from Bennu's surface into sustained orbits. These approaches yield statistically consistent results up to degree and order 3, with the particle-based field being statistically significant up to degree and order 9. Comparisons with a constant-density shape model show that Bennu has a heterogeneous mass distribution. These deviations can be modeled with lower densities at Bennu's equatorial bulge and center. The lower-density equator is consistent with recent migration and redistribution of material. The lower-density center is consistent with a past period of rapid rotation, either from a previous Yarkovsky-O'Keefe-Radzievskii-Paddack cycle or arising during Bennu's accretion following the disruption of its parent body.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Sci Adv
Ano de publicação:
2020
Tipo de documento:
Article