Here's why:
* Earth's Tilt: The Earth is tilted on its axis, which causes different parts of the planet to receive varying amounts of sunlight throughout the year. This is why we have seasons.
* Earth's Orbit: As Earth orbits the Sun, our perspective of the night sky changes. We see different constellations as we face different directions in our orbit.
* Constellation Visibility: Constellations appear to move across the sky over time because of Earth's rotation and orbit.
* During a particular season, we face a particular region of the sky at night.
* As Earth moves in its orbit, we face different regions, revealing different constellations.
In summary: The Earth's orbit around the Sun, coupled with its axial tilt, leads to the seasonal changes in the constellations we see at night.
