When people have looked up at the sky, they have noticed five planets visible to the unaided eye: Mercury, Venus, Mars, Jupiter, and Saturn. These “wanderers” were notable because they changed position relative to the background stars. Ancient peoples did not know what the planets were, but they knew they were significant. Today, we know these five planets, plus Uranus and Neptune (which can be seen through telescopes), and a host of dwarf planets (like Pluto), moons, asteroids, comets, and the Sun and Earth all comprise our solar system. But the five “naked eye” planets (and our own Moon) still are most prominent in our nightly observing, and they are often featured objects in the Observatory’s public telescopes.