Are we alone? This course introduces core concepts in astronomy, biology, and planetary science that enable the student to speculate scientifically about this profound question and invent their own solar systems.
From the lesson
Einstein and the Search for Planets
Einstein’s theory of General Relativity tells us that mass curves space and deflects light. Thus, observations of light deflection can tell us about the distribution of mass. Microlensing observations use this effect to detect planets around distant stars. We discuss how these observations have shown us that planets are as common as stars and imply the existence of “orphan planets”, planets that were ejected by their Suns and are now wandering the Galaxy.