Cassiopeia is not visible all year long. Like all constellations, its visibility depends on your location on Earth and the time of year.

Here's why:

* Earth's Tilt: The Earth's axis is tilted, causing different parts of the planet to face the sun at different times of year. This leads to seasonal changes and the apparent movement of constellations across the sky.

* Circumpolar Constellations: Some constellations, like Cassiopeia, are located near the celestial poles. From certain latitudes, these constellations appear to circle around the pole star, never setting below the horizon. However, they are not visible all year long for everyone.

* Latitude: The further north you are, the more circumpolar constellations you can see. Cassiopeia is a circumpolar constellation for those living at latitudes above about 35° N.

Therefore, while Cassiopeia may be visible year-round for people living at high northern latitudes, it is not visible all year long for everyone on Earth.