Searching for a Black Hole in the Outer Solar System

Abstract

There are hints of a novel object ("Planet 9") with a mass $5-10$ $M_{\oplus }$ in the outer Solar System, at a distance of order 500 AU. If it is a relatively conventional planet, it can be found in telescopic searches. Alternatively, it has been suggested that this body might be a primordial black hole (PBH). In that case, conventional searches will fail. A possible alternative is to probe the gravitational field of this object using small, laser-launched spacecraft, like the ones envisioned in the Breakthrough Starshot project. With a velocity of order $.001c$, such spacecraft can reach Planet 9 roughly a decade after launch and can discover it if they can report timing measurements accurate to $10^{-5}$ seconds back to Earth.

4 pp, additional references

References in corpus (3)

• Constraints on Earth-mass primordial black holes from OGLE 5-year microlensing events
• No large population of unbound or wide-orbit Jupiter-mass planets
• The Brute-Force Search for Planet Nine

Cited by in corpus (4)

• Low-cost precursor of an interstellar mission
• Exploration of the outer solar system with fast and small sailcraft
• The Brute-Force Search for Planet Nine
• Project Lyra: Catching 1I/'Oumuamua -- Using Laser Sailcraft in 2030