Exoplanets

An exoplanet is defined as any planet that exists outside our solar system. While the majority orbit stars, there are also free-floating exoplanets known as rogue planets, which do not have a gravitational anchor to any star. To date, we have confirmed the existence of over 5,600 exoplanets, although it is estimated that billions more remain undiscovered in the vastness of the universe.

The majority of exoplanets that have been discovered so far are located within a relatively small region of our galaxy, the Milky Way. When we say "small," we refer to distances of thousands of light-years; for perspective, one light-year is approximately 5.88 trillion miles (or 9.46 trillion kilometers). Even the closest known exoplanet, Proxima Centauri b, is situated about 4 light-years away from Earth. It is widely believed that there are more planets in our galaxy than there are stars.

By studying the sizes (diameters) and masses (weights) of these exoplanets, we can uncover a fascinating array of compositions, ranging from rocky planets like Earth and Venus to gas giants such as Jupiter and Saturn. Some exoplanets may be primarily composed of water or ice, while others are rich in materials like iron or carbon. We have even identified lava worlds with molten oceans, fluffy planets with densities akin to Styrofoam, and dense planetary cores still in orbit around their stars.