In a lunar eclipse, the Sun, Earth, and Moon are aligned in a specific way. A lunar eclipse occurs when the Earth comes between the Sun and the Moon, blocking the sunlight from reaching the Moon. The positions of the Sun, Moon, and Earth during a lunar eclipse are as follows:
Sun: The Sun is on one side of the Earth, illuminating it. The Sun's rays are blocked by the Earth, causing the Earth to cast a shadow on the Moon.
Earth: The Earth is positioned in the middle, with the Moon on one side and the Sun on the other. The Earth's shadow is cast onto the Moon, leading to the eclipse. The Earth's shadow has two distinct parts: the outer shadow, called the penumbra, and the darker inner shadow, called the umbra.
Moon: The Moon is on the side opposite to the Sun, with the Earth's shadow falling on it. Depending on the alignment and the position of the Moon within the Earth's shadow, different types of lunar eclipses can occur, such as a total lunar eclipse (when the Moon is fully within the Earth's umbra), a partial lunar eclipse (when only a portion of the Moon passes through the Earth's umbra), or a penumbral lunar eclipse (when the Moon passes through the Earth's penumbra but not the umbra).
In contrast, during a "no Moon" or New Moon phase, the positions of the Sun, Moon, and Earth are different. In this phase, the Moon is positioned between the Sun and the Earth, causing the side of the Moon facing the Earth to be in shadow. As a result, the illuminated side of the Moon faces away from the Earth, making it mostly or completely invisible from our perspective on Earth.