Editing Solar system (section)

=== The Boundary of the Solar System ===
The Solar System is not  just made up of the Sun, planets, and moons. It also has an invisible boundary that defines the region influenced by the Sun’s gravity and solar wind. This boundary plays an important role in protecting the planets from cosmic radiation and interstellar particles. '''Heliosphere:''' The '''heliosphere''' is the vast bubble created by the Sun’s solar wind, a stream of charged particles emitted by the Sun. It extends far beyond the orbit of the outer planets and marks the region where the Sun’s gravitational and magnetic influence dominates. The heliosphere acts as a shield, protecting the Solar System from high-energy cosmic rays coming from other parts of the galaxy. Spacecraft like '''Voyager 1''' and '''Voyager 2''' have crossed the outer edges of the heliosphere, entering '''interstellar space''', and provided valuable data about this distant boundary. '''Oort Cloud:''' Beyond the heliosphere lies the '''Oort Cloud''', a theoretical spherical region surrounding the Solar System. The Oort Cloud is believed to contain '''millions of icy bodies and comets''', which serve as a reservoir for long-period comets that occasionally enter the inner Solar System. Though it has not yet been directly observed, scientists infer its existence from the orbits of comets and models of the Solar System’s formation. The Oort Cloud extends nearly a quarter of the distance to the nearest stars, making it the outermost region of the Sun’s gravitational influence. Together, the heliosphere and the Oort Cloud define the true '''boundary of the Solar System'''. The heliosphere marks the active influence of the Sun, while the Oort Cloud represents the distant outer limits where icy objects orbit the Sun. Understanding these regions helps astronomers learn about the Solar System’s formation, its interactions with interstellar space, and the origin of comets that occasionally visit the inner planets.