when do total lunar eclipses occur?
Total lunar eclipses occur when the Earth is directly between the Sun and the Moon. It happens only when the Moon is in its full phase. However, not all full moons result in a total lunar eclipse as the Moon's orbit is tilted with respect to the Earth's orbit around the Sun. This tilt causes the Moon to pass above or below the Earth's shadow during most full moons. Therefore, total lunar eclipses can only occur when the Moon is within a specific range of the Earth's shadow, which is why they are relatively rare events.
Total lunar eclipses occur when the Earth is positioned directly between the Sun and the Moon. This alignment causes the Earth to cast its shadow on the Moon, resulting in a darkening and reddening of the Moon's appearance.
Total lunar eclipses can only occur during a full moon, when the Sun, Earth, and Moon are perfectly aligned in that order. However, not all full moons result in a lunar eclipse because the Moon's orbit is inclined relative to the Earth's orbit around the Sun. The Moon must also be in or near one of the two points in its orbit known as the lunar nodes, where it crosses the ecliptic plane (the plane of Earth's orbit around the Sun).
On average, there are about two or three total lunar eclipses a year, but the exact number can vary. The frequency depends on various factors, including the position of the lunar nodes and the geometry of the Earth-Moon-Sun system.