Misaligned binary star systems can create rogue planets. In single-star systems, planets need to be closely spaced to create a rogue planet. However, in binary systems, planets can be widely spaced and still generate rogues. The combination of gravitational tugs from both the stars and other planets is sufficient to destabilize the orbits of some planets.
Rogue planets are free-floating planets that roam the universe without any revolution to any host star. They can originate from planetary systems in which they are formed and later ejected, or they can also form on their own, outside a planetary system.
The Milky Way alone may have billions to trillions of rogue planets. The nearest rogue planet to Earth is WISE-0855-0714, which was discovered in 2014 and is approximately 7.2 light-years away from us. The mass of this planet is around 10 times of Jupiter
Scientists estimate that there are trillions of rogue planets in our solar system. There’s a 0.5% chance that one of these planets formed in our solar system and ended up in the Oort cloud.
Astronomers are confident that rogue planets exist because simulations of solar system formation show that many planets are formed but don’t end up orbiting the star. They get kicked out of their home system at an early age
Rogue planets are difficult to detect because they don’t orbit a star. The most successful methods for detecting rogue planets are:
- Gravitational microlensing: This method involves watching foreground objects that move in front of background stars. When light passes over these planets, it bends due to gravity.
- Direct observation in the infrared or far infrared: Rogue planets emit radiation in the far infrared.
The transit method doesn’t work well for rogue planets because at least three transits are needed to confirm a planet.
NASA is using the Nancy Grace Roman Space Telescope to detect rogue planets. This telescope detects microlensing, which is when light from a star bends toward a planet’s gravit
A planet is considered rogue if it doesn’t orbit a star. Rogue planets are also known as:
- Interstellar planets
- Orphan planets
- Nomad planets
- Free-floating planets
- Isolated planetary-mass objects
- Starless planets
- Unbound planets
- Wandering planets
Rogue planets can be ejected from their parent system or form from the collapse of a gas cloud that’s too small to form a star. They can range in size from Pluto to larger than Jupiter.
Rogue planets can exist in the Milky Way or be ejected from it entirely. They can also be homes for life
There are between 100 and 100,000 rogue planets for every star in our galaxy. This means that there are around a quadrillion planets wandering through the Milky Way.
Rogue planets are six times more common than planets orbiting parent stars. NASA senior scientist David Bennett estimates that there are 20 times more rogue planets than stars in our galaxy.
Earth-mass planets are 180 times more common than rogue Jupiters. Most rogue worlds are small.
NASA’s Roman Space Telescope could find about 400 Earth-mass rogue planets.
The closest rogue planet to Earth is WISE-0855-0714, which is about 7.2 light-years away. It was discovered in 2014 by astronomer Kevin Luhman using data from the Wide-field Infrared Survey Explorer (WISE). WISE-0855-0714 is a sub-brown dwarf located in the constellation Hydra. It has a mass of around 10 times Jupiter’s.
Other nearby rogue planets include:
- CFBDSIR2149: Located about 120 light-years away.
- 2MASS J1119–1137: Located about 95 light-years away.
- Proxima d: A planet candidate orbiting the red dwarf star Proxima Centauri.
Universe discoveries 