What are exoplanets?

Exoplanets, or extrasolar planets, are defined as planets that exist outside of our solar system, orbiting stars other than the Sun. The discovery of these planets has expanded our understanding of the universe and the potential for diverse planetary systems.

This definition is critical as it includes a vast range of planetary types that could be found in various environments across the galaxy. Exoplanets can vary widely in size, composition, and distance from their host stars, making them a key area of study in contemporary astronomy.

In contrast, the other definitions provided do not accurately capture what exoplanets are. For example, planets that do not orbit any star are known as rogue planets, and while some exoplanets may have rings or be similar to Earth, those characteristics do not define them as exoplanets in the broader sense. Exoplanets encompass all planets that exist beyond our solar system, regardless of their specific traits.