Exoplanet names can look long and complicated at first, but they have a logic behind them that is important to scientists cataloging thousands of planets. Let’s use HD 189733 b (a blue-ish planet where it may rain glass sideways) as an example. The first part of the name is usually the telescope or survey that found it. In this case "HD" stands for the "Henry Draper Catalogue,” a widely-used star catalog. The number 189733 is the order in which the star was catalogued by position (the 189,733rd star added to the catalog). The lowercase letter "b" stands for the planet, in the order in which the planet was found. The first planet found is always named b, with ensuing planets named c, d, e, f and so on.