Planetoidit

Planetoidit, or planetoids, refer to small, rocky celestial bodies that orbit the Sun, typically found in the asteroid belt between Mars and Jupiter, though they can also be located in other regions of the solar system. These objects are smaller than planets and moons but larger than meteoroids, generally ranging from a few meters to hundreds of kilometers in diameter. The term "planetoid" is sometimes used interchangeably with "asteroid," though historically, it was applied more broadly to include objects like dwarf planets and other minor planets.

The majority of known planetoids reside in the asteroid belt, a region densely populated with millions of rocky fragments left over from the early solar system. Some notable examples include Ceres, the largest asteroid and the only dwarf planet within the belt, and Vesta, which is the second-largest and has a well-preserved surface. Planetoids can also be found in other areas, such as near-Earth objects (NEOs), which have orbits that bring them close to Earth, or in the Kuiper Belt, a distant region beyond Neptune populated by icy bodies.

Planetoids vary widely in composition, often containing silicates, metals, and organic compounds. Their surfaces can be heavily cratered, indicating collisions with other objects over billions of years. Some planetoids may have moons of their own, such as the binary asteroid system Didymos and its moonlet Dimorphos, which was studied during NASA’s DART mission.

The study of planetoids provides valuable insights into the early solar system’s formation and the processes that shaped planetary bodies. Missions like NASA’s Dawn spacecraft, which orbited Vesta and Ceres, have helped scientists better understand these objects through direct observation and data collection. Planetoids also pose a theoretical risk to Earth, as some NEOs could potentially collide with the planet, making their study important for both scientific and practical reasons.