In mid-June, astronomers announced the discovery of a terrestrial planet outside of our solar system with conditions that may be favorable for sustaining an atmosphere.

The characteristics of the planets in our solar system indicate that really only two fundamental types of planets exist: those that are similar to Earth (the terrestrial planets) and those that are similar to Jupiter (gas-giant planets). The terrestrial planets include Mercury, Venus, Earth, and Mars. The gas-giant planets include Jupiter, Saturn, Neptune, and Uranus. The size and other properties of Pluto, however, make it unlike either of the terrestrial or gas-giant planets.

Despite their similarities, however, planets are also like people -- they have their own individual characteristics that distinguish each from all the other planets. Visit Space.com to find out what scientists are discovering about the personality of their latest discovery.