1. Earth's Rotation: As the Earth spins on its axis, the sky appears to rotate around us. This means that the constellations we see will change throughout the night, and different constellations will be visible at different times of the year.
2. Earth's Orbit: As Earth orbits the Sun, our perspective on the distant stars changes. This means that different constellations are visible during different seasons. For example, constellations like Orion are only visible in the winter sky, while constellations like Sagittarius are only visible in the summer sky.
