![Orbital trajectories of two example scattering experiments. Left: An interaction that results in a free-floating planet-moon pair. Right: An interaction that results in a free-floating planet and a separate free-floating moon. The starting points of the bodies are indicated by the black dots. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Planet-moon.png?resize=1200%2C720&ssl=1)
[astro-ph.EP] Free-floating planet-moon pairs (FFPMs) may form when planetary systems experience close stellar encounters.
Rogue Planet
Posted inAstronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Interstellar, Status Report
A Free-floating-Planet Microlensing Event Caused By A Saturn-mass Object
A population of free-floating planets is known from gravitational microlensing surveys. None have a directly measured mass, owing to a degeneracy with the distance, but the population statistics indicate that […]
Posted inAstrogeology, Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Origin & Evolution of Life, Status Report
Life In The Dark: Potential Urability Of Moons Of Rogue Planets
Free-floating (rogue) planets are thought to be numerous in the Galaxy and may retain their moons after ejection from their natal systems. If those satellites acquire or preserve orbital eccentricity, […]
Posted inAstrogeology, Astronomy & Telescopes, Exoplanets, -moons, -comets, Press Release
A Rogue Planet Is Growing At Record Rate Of Six Billion Tons Per Second
Astronomers have identified an enormous ‘growth spurt’ in a so-called rogue planet. Unlike the planets in our Solar System, these objects do not orbit stars, free-floating on their own instead.
Posted inAstronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report
The JWST Weather Report From the Isolated Exoplanet Analog SIMP 0136+0933: Pressure-Dependent Variability Driven by Multiple Mechanisms
Isolated planetary-mass objects share their mass range with planets but do not orbit a star. They lack the necessary mass to support fusion in their cores and thermally radiate their […]
Posted inExoplanets, -moons, -comets, Status Report
Formation of Free-floating Planetary Mass Objects Via Circumstellar Disk Encounters
The origin of planetary mass objects (PMOs) wandering in young star clusters remains enigmatic, especially when they come in pairs. They could represent the lowest-mass object formed via molecular cloud […]
Posted inAstronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Status Report, Stellar Cartography
The Origin Of Free-floating Objects In The Galaxy
The Milky way Galaxy is brimming with free-floating objects, including stars, planets and planetesimals. For the purpose of this chapter, we define a free-floating object as a solid body that […]
Posted inAstronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Interstellar, Press Release, Stellar Cartography
In Six New Rogue Worlds, Webb Telescope Finds More Star Birth Clues
The James Webb Space Telescope has spotted six likely rogue worlds—objects with planetlike masses but untethered from any star’s gravity—including the lightest ever identified with a dusty disk around it.
Posted inAstronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Status Report, Stellar Cartography
Predicting The Galactic Population Of Free-floating Planets From Realistic Initial Conditions
We present the first prediction for the mass distribution function of Galactic free-floating planets (FFPs) that aims to accurately include the relative contributions of multiple formation pathways and stellar populations.
Posted inAstronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Interstellar, Press Release, Stellar Cartography
Study Finds Rogue Planets Can Become Permanently Trapped in Sun’s Orbit
Objects from interstellar space, such as rogue planets and asteroids, can become permanently trapped in the Sun’s orbit as a result of the combined gravitational effects of the Sun and […]