Astronomy Practice Exam 2026 – Complete Preparation Guide

The celestial equator is tilted approximately 23.5 degrees with respect to the ecliptic plane. This tilt is a result of the axial tilt of the Earth, known as obliquity, which is the angle between the Earth’s rotational axis and its orbital plane around the Sun. This 23.5-degree tilt is significant because it leads to the seasonal variations we experience on Earth.

As the Earth orbits the Sun, different parts of the planet receive varying amounts of sunlight throughout the year due to this axial tilt, creating the cycle of seasons. The celestial equator is an imaginary projection of the Earth's equator into space, and as a result of the axial tilt, it appears tilted relative to the ecliptic, which is the apparent path of the Sun across the sky as a result of Earth's orbit around it. This relationship helps astronomers understand celestial events and the behavior of objects in the sky.

Understanding the 23.5-degree tilt is crucial for grasping the fundamentals of celestial navigation and astronomical observations, which rely on the positions of celestial bodies in relation to both the celestial equator and the ecliptic.