 We have now visited a number of stars from our local neighborhood. We started with the nearest stars where parallax measurements from Earth-bound telescopes were good enough. We then moved out to the furthest reaches of the neighborhood using Hipparchus-based parallax measurements. And we went even further with Gaia. In our segment on the solar system, we extended the direct measurement and triangulation to include parallax for the planets. This segment covered how we measured stellar distance, mass, luminosity, and motion, all based on parallax techniques just like we did with the solar system. And thanks to the Hipparchus and Gaia satellites, we know the parallax for hundreds of thousands of stars, which are relatively close to the Sun, so we can add stars to the reach of the parallax rung on our cosmic distance ladder. But if all we had was parallax, we'd know very little about our galaxy, and virtually nothing about the universe beyond. But the only thing we get from a star is its light.