Many people believe that a blinking sky object is a star, but a steadily glowing one is a planet or a satellite. However, the flickering effect depends not on the type of sky object but the observation conditions and air vibrations. Planets may also twinkle while hanging low above the horizon. To know for sure if you see a star or a planet, use Sky Tonight: point your device at the object in question, and the app will tell you its name.