Is the recently proposed Mars-sized perturber at $65-80\text{AU}$ ruled out by the Cassini ranging data?

Abstract

Recently, the existence of a pointlike pertuber PX with $1m_{\text{Mars}}\lesssim m_{\text{X}}\lesssim 2.4m_{\oplus }$ supposedly moving at $65-80\text{AU}$ along a moderately inclined orbit has been hypothesized in order to explain certain features of the midplane of the Kuiper Belt Objects (KBOs). We preliminarily selected two possible scenarios for such a PX, and numerically simulated its effect on the Earth-Saturn range $\rho (t)$ by varying some of its orbital parameters over a certain time span; then, we compared our results with some existing actual range residuals. By assuming $m_{\text{X}}=1m_{\text{Mars}}$ and a circular orbit, such a putative new member of our Solar System would nominally perturb $\rho (t)$ by a few km over $\Delta t=12\text{yr}(2004-2016)$. However, the Cassini spaceraft accurately measured $\rho (t)$ to the level of ${\sigma }_{\rho }\simeq 100\text{m}$. Nonetheless, such a scenario should not be considered as necessarily ruled out since the Cassini data were reduced so far without explicitly modeling any PX. Indeed, a NASA JPL team recently demonstrated that an extra-signature as large as 4 km affecting the Kronian range would be almost completely absorbed in fitting incomplete dynamical models, i.e. without PX itself, to such simulated data, thus not showing up in the standard post-fit range residuals. Larger anomalous signatures would instead occur for $m_{\text{X}}>1m_{\text{Mars}}$. Their nominal} amplitude could be as large as $50-150\text{km}$ for $m_{\text{X}}=2.4m_{\oplus }$, thus making less plausible their existence.

LaTex2e, 10 pages, no tables, 2 figures. Accepted for publication in the Research Topic "From Comets to Pluto and Beyond: Kuiper Belt Objects and Investigations" of Frontiers in Astronomy and Space Sciences

References in corpus (12)

• Evidence for a Distant Giant Planet in the Solar System
• Constraints on MOND theory from radio tracking data of the Cassini spacecraft
• Observational constraints on the orbit and location of Planet Nine in the outer solar system
• Extreme trans-Neptunian objects and the Kozai mechanism: signalling the presence of trans-Plutonian planets
• New Extreme Trans-Neptunian Objects: Towards a Super-Earth in the Outer Solar System
• Constraints on the location of a possible 9th planet derived from the Cassini data
• The curiously warped mean plane of the Kuiper belt
• The Comparative Exploration of the Ice Giant Planets with Twin Spacecraft: Unveiling the History of our Solar System
• Orbital clustering of distant Kuiper Belt Objects by hypothetical Planet 9. Secular or resonant ?
• Consequences of a Distant Massive Planet on the Large Semi-major Axis Trans-Neptunian Objects
• Preliminary constraints on the location of the recently hypothesized new planet of the Solar System from planetary orbital dynamics
• Evidence for a possible bimodal distribution of the nodal distances of the extreme trans-Neptunian objects: avoiding a trans-Plutonian planet or just plain bias?

Cited by in corpus (2)

• Is There an Earth-like Planet in the Distant Kuiper Belt?
• A search for Planet Nine with small spacecraft:Three-body, post-Newtonian, non-gravitational, planetary and Kuiper Belt effects