Describing something that resembles a planet in appearance, characteristics, or behavior. This includes features like having a rounded shape, possessing a significant gravitational field, exhibiting orbital motion, and potentially harboring an atmosphere and surface features. It can refer to celestial bodies beyond the recognized planets of our solar system, such as exoplanets, or to objects in our own solar system that share planetary attributes. It's often used to compare and contrast the physical properties of different celestial objects, emphasizing similarities and differences.
Planet-like meaning with examples
- Observations of the exoplanet Kepler-186f reveal it has a size and potential mass suggesting a rocky, planet-like composition, similar to Earth. Its discovery fueled hopes of finding another Earth-like planet. Further studies are needed to investigate whether it has a planet-like atmosphere, surface, and presence of water, possibly supporting life. Scientists use this data to understand the evolution of planets, and their properties.
- The large moon, Titan, orbiting Saturn, exhibits many planet-like characteristics: a dense atmosphere, stable surface liquids (methane), and varied topography including mountains and river systems. Its atmosphere, while distinct from Earth's, is of the most intriguing, as it shares similarities in chemistry. These features make Titan a fascinating subject for research, and a place where liquid might be accessible.
- The protoplanetary disk around a young star exhibits planet-like structures, visible as gaps and rings, suggesting that planet formation is underway. The dust and gas swirling around the star will collect, forming planetesimals, then planets, and possibly moons. These disks give information on the process and the formation of planets, even before they are planet-like.
- Some dwarf planets, such as Ceres, display a rounded shape and features like a possible subsurface ocean, leading astronomers to describe them as planet-like bodies, though they are smaller and share their orbit with other objects. Their size and composition make them intriguing objects for studying, and make it necessary to define what makes an object 'planet-like'.