Going Farther

Astronomers have discovered more than 1,000 planets in star systems beyond our own. Most of those planets are quite close to their parent stars. This diagram, for example, shows the layouts of several planetary systems discovered by the Kepler spacecraft, in which most or all of the planets are closer to their parent stars than Earth is to the Sun. Astronomers at McDonald Observatory, however, are hunting for planets in more-distant orbits, which are much more difficult to detect. Such planets can help theorists understand the birth and evolution of all planetary systems, including our own. [NASA Ames/Dan Fabrycky (UC Santa Cruz)]