Learning about far-away planets is useful if we want to know more about planets in general, such as how do they form and what kinds of planetary systems are we

Learning about far-away planets is useful if we want to know more about planets in general, such as how do they form and what kinds of planetary systems are we most likely to find outside our solar system? Even if we never visit that particular planet, we may learn something useful that tells us something about planets nearby, or even about our own solar system. At this point, we're just collecting data about extra-solar planets, which we weren't sure even existed until recently. With so many unknowns, it's exciting whenever we can fill in our knowledge gaps just a little bit.