The Hunt for Captured Planets: Analyzing the Potential Discovery of Small Rogue Objects in Our Solar System

Tuesday - April 2 2024, 20:00 UTC - 7 months ago

A recent study suggests that there could be small rogue objects, ranging from the size of Mars to the size of Mercury, captured into our solar system. Current predictions estimate the existence of 1.2-2.7 Mars-sized objects and 2.4-5.2 Mercury-sized objects. Additional exploration is needed to refine these estimates. Upcoming instruments like the Nancy Grace Roman Telescope and LSST will aid in the search for these captured planets. It is possible that even smaller objects, such as dwarf planets, could be detected by these instruments.

A recent study conducted by astronomers explored the possibility of small rogue objects being captured into our solar system. These objects, which could range from the size of Mars to the size of Mercury, would have a median distance of 1400 AU from the Sun. This research was based on adopting logarithmic bins centered at the Mars mass and Mercury mass, and it predicted the existence of ∼2.7 objects with mass comparable to that of Mars and ∼5.2 with mass comparable to that of Mercury.

While these findings are intriguing, the study does not account for the possibility of smaller objects being captured as well. It is estimated that there could be dozens of Pluto-sized objects that have been captured into our solar system. This could have significant implications for our understanding of the formation and evolution of our solar system.

The hunt for captured planets will be aided by upcoming instruments such as the Nancy Grace Roman Telescope and the Large Synoptic Survey Telescope (LSST). The LSST, in particular, has the potential to discover free-floating planets with a blind shift-and-stack algorithm. In addition, LSST is expected to detect extreme trans-Neptunian objects, which will help refine the estimates for captured objects in our solar system.

One of the main questions that this research raises is the detectability of these captured planets. While the current study focused on objects with mass comparable to Mars and Mercury, it is possible that smaller objects could also be detected. The Nancy Grace Roman Telescope and LSST will be important tools in exploring this further, and the statistics from Sumi et al. (2023) suggest that even dwarf planets with masses similar to Pluto could be discovered early on in the LSST observing program.