Exploring the Solar System

Most people can name the planets. Very few know how we actually learned what they're like. For most of human history, planets were just lights in the sky. Then, in a few decades, we sent machines to fly past them, orbit them, land on them, and bring pieces of them back. That shift, from speculation to direct measurement, is one of the most dramatic turns in the history of science.

This course follows that story from the beginning. You'll see how ancient sky-watchers gave way to spacecraft engineers, and why it took a space race to turn planetary science from a backwater into one of the most active fields in research. You'll learn how scientists read a planet's temperature, composition, and history from data collected millions of miles away. And you'll trace the logic of exploration missions: why a flyby is cheaper than an orbiter, why an orbiter tells you more, and why a sample-return mission is worth the decade-long wait.

By the end, you'll understand the comparative view that runs through all of planetary science. The same processes, cratering, volcanism, differentiation, appear across every world we've visited. That pattern is what makes it possible to look at a surface and read its age, or look at Europa and have a serious scientific conversation about whether something might be alive there. This is not a course about memorizing facts. It's about learning to see the solar system the way researchers actually do.