Can an Earth-mass planet exist between Jupiter and Saturn? A numerical experiment

Author(s)
Rudolf Dvorak, Manfred Cuntz
Abstract

Motivated by previous studies about asteroids situated between Jupiter and Saturn, where long-term stable orbits with small eccentricities and low inclinations have been identified, we extend this research by placing an Earth-mass planet in the region between Jupiter and Saturn. We pursued numerical integrations of the equations of motions for the outer solar system encompassing Jupiter, Saturn, Uranus, and Neptune, as well as the additional Earth-mass planet. This 6-body system has been integrated with the Lie method for up to 500 Myr. The default initial stable zone for the Earth-mass planet has been assumed between 7.04 and 7.31 au based on the results from previous studies by our group. We explored each region separately for 360 Earth-mass planets (assuming different mean anomalies) and inspected the respective escape times (ETs). The overall picture shows that the most stable orbits occur between 7.12 and 7.28 au. Furthermore, the mean of the ETs for all 360 mean anomalies between 7.24 and 7.12 au gradually decreases from ET = 11 to 0.9 Myr, although smaller values are obtained for the median due to outliers. To check the role of stability of the Earth-mass planet depending on its initial inclination, we focused on three regions (i.e., 7.23, 7.24, and 7.25 au) in terms of their ETs assuming i = 1°, 3°, and 5°; however, no significant differences were found. Hence, the general possibility of an Earth-mass planet situated between Jupiter and Saturn in the Solar System's distant past is highly notable, although it would have been a transient event.

Organisation(s)
Department of Astrophysics
External organisation(s)
University of Texas, Arlington
Journal
Astronomische Nachrichten
Volume
344
ISSN
0004-6337
DOI
https://doi.org/10.1002/asna.20220077
Publication date
03-2023
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy, 103004 Astrophysics
Keywords
ASJC Scopus subject areas
Astronomy and Astrophysics, Space and Planetary Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/ea3bc953-de93-4367-a319-d156d5cf7097