The origin of binary rogue planets, also known as unbound or free-floating planets, is still a topic of active research in astronomy and planetary science. Two main theories attempt to explain their existence:

1. Ejection from Planetary Systems:

One theory suggests that binary rogue planets could be ejected from existing planetary systems through various dynamical processes. Gravitational interactions within a multi-planet system can cause one or more planets to be ejected into unbound orbits, eventually becoming free-floating. This ejection can occur due to gravitational encounters between planets or the influence of a massive perturber like a nearby star.

2. Failed Star Formation:

Another theory proposes that binary rogue planets may form as failed stars. During the process of star formation, when a collapsing cloud of gas and dust fragments into multiple clumps, it's possible for some fragments to fail to accumulate enough mass to become stars. These clumps can still form planet-like objects that lack the mass and internal pressure required to sustain nuclear fusion. These failed stars then wander as rogue planets.

It's worth noting that these are just two of the proposed scenarios, and there could be other mechanisms that contribute to the formation of binary rogue planets. Additionally, the distinction between rogue planets and brown dwarfs (objects with masses between planets and stars) can be challenging, further complicating the study of these celestial objects.